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| J Clin Microbiol, 1986 Oct, 24(4), 661 - 4 Evidence for production of an enterotoxin and cholera toxin cross-reactive factor by Aeromonas hydrophila; Chopra AK et al.; The enterotoxins produced by Aeromonas hydrophila were examined for biological activity by the rabbit ileal loop and suckling mouse assays, as well as by elongation of CHO cells . Antigenic evaluation of the culture filtrates from various isolates of A . hydrophila was performed by enzyme-linked immunosorbent assay with anti-cholera toxin and anti-Aeromonas enterotoxin . Heat stability data demonstrated the presence of a heat-labile cholera toxin cross-reactive factor and a heat stable non-cholera toxin cross-reactive enterotoxin . The biological activities of both enterotoxins were heat labile at 56 degrees C for 20 min. Can J Microbiol, 1986 Oct, 32(10), 814 - 9 Melanogenesis in murine B16 cells exposed to Aeromonas hydrophila cytotoxic enterotoxin; Bunning VK et al.; Specific markers (growth, melanogenesis) of B16 murine melanoma cells in culture were used as indicators of toxin production by Aeromonas hydrophila . Cytotonic enterotoxinlike activity (inhibited growth, raised tyrosinase activity, and melanin accumulation) occurred at cytotoxic end points of purified beta-hemolysin and several culture filtrates . Antihemolysin rabbit serum inhibited this activity . A hemolysin-neutralized culture filtrate concentrate (10X) failed to elevate tyrosinase relative to untreated and cholera toxin treated controls . Similar dilution profiles using Chinese hamster ovary cells showed limited cell extension only at cytotoxic end points with antihemolysin inhibiting this activity . Cytotoxicity of Chinese hamster ovary cells and B16 cells was proportional to hemolytic activity, with B16 cells showing about 100-fold greater sensitivity on a per cell basis . Cell culture cytotoxicity attributed to beta-hemolysin correlated with reactivity in rabbit ileal loop assays . The ADP-ribosyl transferase activity of concentrated (10X) A . hydrophila culture filtrates and fractions thereof was negative . Apparently sublethal doses of A . hydrophila beta-hemolysin can nonspecifically stimulate cyclic adenosine monophosphate mediated events in melanoma and Chinese hamster ovary cell assays, producing lower activities than cholera toxin with shorter lag times. Hepatogastroenterology, 1986 Aug, 33(4), 187 - 90 New unusual forms of colitis . Report of four cases with known and unknown etiology; Bayerdorffer E et al.; Four patients with colitis, in two of whom the etiology was unknown, are presented . One patient with discontinuous segmental colitis was infected by Aeromonas hydrophila, and another with presumed idiopathic inflammatory bowel disease was superinfected by this pathogen . Although Aeromonas hydrophila has been known as a rare cause of diarrhea in our region, it is in the first instance reported to cause severe long-lasting colitis as well as superinfection of idiopathic inflammatory bowel disease (IIBD) . Another patient presented with segmental ischemic colitis which was rather atypical and of unknown etiology; the patient was young and had no predisposing factors for vascular occlusive disease . The fourth patient with long-lasting segmental granulomatous colitis which was suspected to be parasitic in origin remained without a definitive diagnosis . This presentation of patients with endoscopically proven colitis should in view of our increasing knowledge of colitis remind us to keep a look out for new infections and other forms of inflammatory bowel disease. J Clin Microbiol, 1986 Aug, 24(2), 228 - 32 Purification and characterization of an Aeromonas hydrophila hemolysin; Asao T et al.; A hemolysin produced by Aeromonas hydrophila CA-11, isolated from an environmental source, was purified by sulfopropyl-Sephadex C-25 chromatography at pH 5.0 . This hemolysin caused fluid accumulation in infant mouse intestines and rabbit intestinal loops and killed Vero cells, as did the hemolysin produced by strain AH-1, isolated from a diarrheal case . In polyacrylamide gel electrophoreses at pHs 4.0 and 9.4 and in thin-layer isoelectric focusing, CA-11 hemolysin migrated as a single band to a position different from that of AH-1 hemolysin . Immunodiffusion tests indicated that CA-11 hemolysin was immunologically related to AH-1 hemolysin but possessed unique antigenic determinants . Neutralization tests with antihemolysin sera also demonstrated immunological cross-reactivity between AH-1 and CA-11 hemolysins . These results apparently indicate that the hemolysins produced by the two strains of A . hydrophila are immunologically and physicochemically different from each other. J Med Microbiol, 1986 Aug, 22(1), 51 - 5 Biochemical characteristics, enterotoxigenicity and susceptibility to antimicrobial agents of clinical isolates of Aeromonas species encountered in the western region of Saudi Arabia; Gosling PJ; The biochemical characteristics, enterotoxigenicity and susceptibility to antibiotics are reported for 22 strains of Aeromonas species isolated from clinical specimens in the Western Region of Saudi Arabia . Aeromonas caviae was the species most frequently observed; a high proportion of these strains fermented lactose, whereas lactose fermentation was not observed in strains of A . hydrophila and A . sobria . Enterotoxigenicity, as judged by cytotoxicity in tissue culture was observed in three of four A . hydrophila strains and six of seven A . sobria strains, but in only one of 11 A . caviae strains . Two schemes for the biochemical assessment of enterotoxigenicity were found to be in 91% and 86% agreement respectively with cytotoxicity studies and in 95% agreement with each other . No single biochemical test correlated fully with enterotoxigenicity, but 86% of strains that oxidized gluconate produced a cytotoxin . Most strains were inhibited by concentrations of gentamicin, amikacin, chloramphenicol and tetracycline achievable in plasma . Most strains were resistant to broad-spectrum penicillins and many were also resistant to cefuroxime and cefoxitin. Surgery, 1986 Aug, 100(2), 214 - 21 Thromboxane A2 mediates hemodynamic and respiratory dysfunction in graded bacteremia; Slotman GJ et al.; Thromboxane A2 has been implicated as a mediator of cardiorespiratory dysfunction in sepsis . This study evaluated whether or not thromboxane A2 was necessary or sufficient for these adverse effects to occur during bacteremia . Fourteen adult swine under barbiturate anesthesia and breathing room air were monitored with arterial and pulmonary artery catheters . Animals were studied for 4 hours in three groups: group I, graded infusion of 10(9)/ml Aeromonas hydrophila; group II, Aeromonas hydrophila infusion plus SQ 29,548 (thromboxane A2 antagonist); and group III, U46619 (thromboxane A2 agonist) infusion in normal swine to pulmonary artery pressures observed in group I . Hemodynamic parameters, arterial and mixed venous blood gases, and plasma thromboxane B2 and prostaglandin 6-keto-F1 were measured . At sacrifice after 4 hours, wet-to-dry lung weights were calculated . Results indicated that thromboxane A2 was necessary and sufficient for the development of pulmonary hypertension and impaired alveolar-capillary oxygen diffusion in graded bacteremia . It was necessary but not sufficient for increased lung water to occur and sufficient but not necessary for decreased cardiac index and stroke volume index . Thromboxane A2 was neither sufficient nor necessary to the pathophysiology of systemic hypotension during graded bacteremia . Plasma prostaglandin 6-keto-F1 levels were increased in hypotensive animals with sepsis, suggesting its involvement in hypotension during sepsis. Mol Gen Genet, 1986 Aug, 204(2), 289 - 95 Molecular cloning and expression in Escherichia coli of the structural gene for the hemolytic toxin aerolysin from Aeromonas hydrophila; Howard SP et al.; The structural gene for the hemolytic toxin aerolysin has been cloned into the plasmid vectors pBR322 and pEMBL8+ . The gene was localized on the hybrid plasmids by analysis of plasmids generated by transposon mutagenesis . The sequence of the first 683 bases of an insert in pEMBL8+ was determined and shown to encode the amino terminus of the protein as well as a typical signal sequence of 23 amino acids . Aerolysin is produced by E . coli cells containing the cloned aerolysin gene and it is processed normally by removal of the signal sequence, however it is not released from the cell . The protein appears to be translocated across the inner membrane of E . coli as its signal sequence is removed and the processed protein can be released by osmotic shock. J Bacteriol, 1986 Jul, 167(1), 368 - 74 Cloning, expression, and mapping of the Aeromonas hydrophila aerolysin gene determinant in Escherichia coli K-12; Chakraborty T et al.; DNA sequences corresponding to the aerolysin gene (aer) of Aeromonas hydrophila AH2 DNA were identified by screening a cosmid gene library for hemolytic and cytotoxic activities . A plasmid containing a 5.8-kilobase EcoRI fragment of A . hydrophila DNA was required for full expression of the hemolytic and cytotoxic phenotype in Escherichia coli K-12 . Deletion analysis and transposon mutagenesis allowed us to localize the gene product to 1.4 kilobases of Aeromonas DNA and define flanking DNA regions affecting aerolysin production . The reduced hemolytic activity with plasmids lacking these flanking regions is associated with a temporal delay in the appearance of hemolytic activity and is not a result of a loss of transport functions . The aerolysin gene product was detected as a 54,000-dalton protein in E . coli maxicells harboring aer plasmids and by immunoblotting E . coli whole cells carrying aer plasmids . We suggest that the gene coding aerolysin be designated aerA and that regions downstream and upstream of aerA which modulate its expression and activity be designated aerB and aerC, respectively. J Gen Microbiol, 1986 Jul, 132 ( Pt 7), 1975 - 9 Characterization of extracellular metallo- and serine-proteases of Aeromonas hydrophila strain B51; Nieto TP et al.; The extracellular proteases of Aeromonas hydrophila B51 were stable on heating (56 degrees C) and on storage at 4 degrees C or -20 degrees C . Inhibitor studies showed that 72% of the total activity was inhibited by EDTA (a metalloprotease inhibitor) and 26% was inhibited by phenylmethanesulphonyl fluoride (a serine protease inhibitor) . Analytical isoelectric focussing revealed the presence of 33 proteins in the crude extracellular products . Using a casein overlay technique three separate zones of proteolytic activity were detected: a zone with pI 6.5-6.8, formed of two closely focussed bands (possibly isomers of the same protease) and completely inhibited by EDTA; a single band with pI 7.0, which was inhibited by EDTA; and a diffuse zone with pI 8.3-8.5, which was only partially inhibited by EDTA . It is concluded that the serine protease activity focussed in this latter zone . These results indicate the presence of at least four, and possibly five proteases . Our results differ substantially from those reported by other workers using different isolates and it is suggested that significant differences in the character of extracellular products and extracellular proteases exist between different isolates of A . hydrophila. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 345 - 50 Protective efficacy of Aeromonas hydrophila vaccines in nile tilapia; Ruangpan L et al.; Protection and serum antibody production against Aeromonas hydrophila was examined in nile tilapia, Tilapia nilotica (L.) . Intraperitoneally injected formal in-killed and Freunds complete adjuvant vaccines were compared using different doses (2.9 X 10(7) and 2.9 X 10(9) cfu/ml) . Upon challenge, the protective ability and antibody titers resulting were significantly different between vaccinated and unvaccinated groups . A relative level of protection of 100% was obtained within two-weeks, and a maximum level of 53-61% protection was found one-week post-vaccination. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 339 - 44 Surface antigens of virulent strains of Aeromonas hydrophila; Dooley JS et al.; Antiserum was raised in rabbits to whole cells of a representative strain from a group of A . hydrophila strains exhibiting enhanced virulence for fish . The major surface antigens of the strain were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting . The lipopolysaccharide (LPS) was examined using SDS-PAGE and silver staining . It was found to possess O polysaccharide chains of homogeneous length that were highly immunogenic . The LPS was conserved both morphologically and antigenically throughout the high virulence group . Heat-labile protein antigens were detected after absorption of the antiserum with boiled cells of the homologous strain . Only one major protein antigen, with a molecular weight of approximately 52,000, was present in outer membrane preparations or in whole cell lysates . A representative strain from the high virulence group, strain TF7, was shown by electron microscopy to be covered by a regular surface protein array (S-layer) which was found to be composed primarily of the 52 KD protein antigen . All the other members of the A . hydrophila high virulence group were shown to possess similar S-layers. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 331 - 8 Does Aeromonas salmonicida affect the immune system of carp, Cyprinus carpio L.? Pourreau CN, Evenberg D, de Raadt WM, van Mechelen JA, van Muiswinkel WB. Aeromonas salmonicida is a significant bacterial pathogen of cyprinid and salmonid fishes causing the systemic disease furunculosis . Several observations led us to believe that A . salmonicida was able to evade or suppress the immune system of the fish: injection of whole bacteria or surface antigens was unsuccessful at protecting fish against lethal challenges; memory did not develop in survivors of sublethal infections; diseased fish often carried other opportunistic bacterial pathogens in addition to A . salmonicida, and serum protein and particularly immunoglobulin significantly decreased during A . salmonicida infections . We tested the ability of fish sublethally infected with virulent and avirulent A . salmonicida to mount a humoral immune response to sheep erythrocytes and found fewer plaque forming cells in the pronephros and lower serum anti-SRBC antibodies in infected fish as compared to controls . We also monitored the cellular immune response of diseased fish by skin allograft rejection and found an enhancement of the response that increased as the disease progressed . However, the extend of inflammation was reduced in infected fish as compared to non-infected animals . At this moment these preliminary observations are difficult to explain . Our future research will focus more specifically on cell populations that may be affected by A . salmonicida. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 321 - 30 Blood changes in carp (Cyprinus carpio) induced by ulcerative Aeromonas salmonicida infections; Evenberg D et al.; Only recently Aeromonas salmonicida has been recognized as a significant bacterial pathogen in ulcerative disease of cyprinid fish . Our attempts to formulate a vaccine based on bacterial surface antigens were unsuccessful in conferring reliable protection against lethal challenge . This lead us to study pathological changes in the humoral defense system during ulcerative A . salmonicida infection in carp . High numbers of opportunist pathogens such as A . hydrophila and Pseudomonas sp . were frequently recovered from the internal organs of moribund fish, in addition to A . salmonicida . These findings together with leucopenia in moribund fish suggest that pathogenesis is characterized by a state of immune suppression . In addition, fish which had sustained a sublethal infection were not protected against a subsequent lethal challenge . However, fish previously injected with a concentrated and inactivated culture supernatant showed protection . Differential blood cell counts did not differ between experimental and control groups during sublethal infection in contrast to serum proteins . Furthermore infected non-immune carp showed a progressive decrease of immunoglobulin and total serum protein levels before the day of peak mortality whereas protected carp maintained the immunoglobulin concentration despite a decrease in protein . Our observations suggest the involvement of multiple pathogenic events, affecting different parts of the humoral defense system during ulcerative A . salmonicida infection . The immunosuppressive effects can be minimized by prior vaccination with culture supernatant. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 287 - 96 Effect of an immunopotentiator on Aeromonas salmonicida infection in rainbow trout (Salmo gairdneri); Kitao T et al.; The immunoactive peptide FK-565 (heptanoyl-y-D-glutamyl-(L)-mesodiaminopimelyl-(D)-alanine) was found to induce protection against intraperitoneal Aeromonas salmonicida infection in rainbow trout (Salmo gairdneri Richardson) . The survival rate was as high as 60% when FK-565 was given intraperitoneally as a single dose (1mg/kg) one day before bacterial challenge . A non-specific stimulation of phagocytic cells by FK-565 at an early stage of the bacterial infection may contribute to the resistance observed . The phagocytic activity of peritoneal phagocytic cells as well as phagocytic cells of the pronephros were stimulated by FK-565 in vivo and in vitro, respectively, as compared to untreated control fish . Furthermore, decreased activity of phagocytic cells previously immunosuppressed with cyclophosphamide was rapidly restored by application of FK-565. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 223 - 34 Interaction between Aeromonas salmonicida and peritoneal macrophages of brook trout (Salvelinus fontinalis); Olivier G et al.; The phagocytic and bactericidal properties of peritoneal macrophages obtained from brook trout (Salvelinus fontinalis), injected with either glycogen or a modified Freund's complete adjuvant (MFCA), were evaluated against an avirulent and a virulent strain of Aeromonas salmonicida . Avirulent bacteria were effectively phagocytized and killed by macrophages obtained from fish injected with both irritants . With glycogen-elicited macrophages, no enhancement of killing was observed following opsonization of avirulent bacteria with specific antibodies . A killing index (K.I.) of 38 was obtained, compared to a K.I . of 39 for unopsonized bacteria . When avirulent bacteria were opsonized with complement, the K.I . was increased to 67 . Virulent bacteria were less susceptible to the phagocytic and the bactericidal activities of glycogen-elicited macrophages, even after opsonization with antibodies and/or complement, K.I . of 9 to 15 . In contrast, MFCA-elicited macrophages showed increased phagocytic and bactericidal activities against both strains . The K.I . of unopsonized virulent bacteria was increased to 47 and 46 compared to K.I . of 4 and 7 obtained with glycogen-elicited macrophages. Eur J Clin Microbiol, 1986 Jun, 5(3), 311 - 6 Incidence and virulence of Aeromonas species in feces of children with diarrhea; Megraud F; Aeromonas spp . occurring in feces of children with diarrhea were studied . Forty-eight strains were isolated from 2,025 specimens during a one year period . Only 11 of 44 strains tested yielded virulence factors (cytotoxin, hemolysin and hemagglutinin) . Six strains were identified as Aeromonas sobria and five as Aeromonas hydrophila . The other strains isolated were identified as Aeromonas caviae . The biochemical characteristics associated with virulence factors were a positive Voges-Proskauer reaction, production of gas from glucose, fermentation of mannose, and absence of beta-lactosidase . Beta-D-glucosidase and esculin hydrolysis were the main characteristics used to differentiate Aeromonas sobria from the other two species . The incidence of Aeromonas spp . with virulence factors in feces of children with diarrhea would seem to vary widely from one area to another. J Med Microbiol, 1986 Jun, 21(4), 319 - 24 Partial characterisation of a soluble haemagglutinin from human diarrhoeal isolates of Aeromonas; Stewart GA et al.; A soluble haemagglutinin has been identified in cell-free culture supernates of human diarrhoeal isolates of Aeromonas sobria, A . hydrophila and A . caviae . It was oligomeric; a major peak of haemagglutinating activity had an apparent mol . wt of 780,000 but there was haemagglutinating activity throughout the mol . wt range less than 40,000- greater than 10(6) . Human group O, A and B, horse, rabbit, chicken and rat erythrocytes, but not those of sheep and cow, were agglutinated by the soluble haemagglutinin, in contrast to the cell-bound agglutinin . Agglutination was inhibited by fetuin, a complex glycoprotein, but not by simple sugars . The haemagglutinating activity was not affected by 0.5 M NaCl, dithiothreitol or the presence or absence of Ca++ . It was unrelated to the haemolytic, enterotoxigenic and proteolytic activities present in cell-free extracts of A . sobria . All A . sobria, 73% of A . hydrophila and 68% of A . caviae strains tested produced this soluble haemagglutinin . A . caviae does not appear to be an enteric pathogen, therefore this soluble haemagglutinin alone is unlikely to be a virulence factor in Aeromonas spp. J Clin Microbiol, 1986 Jun, 23(6), 1140 - 2 Production of "Asao toxin" by Aeromonas strains isolated from feces and drinking water; Notermans S et al.; Cultures of Aeromonas species were tested for production of a toxin recently purified by Asao et al . (T . Asao, Y . Kinoshita, S . Kozaki, T . Uemura, and G . Sukaguchi, Infect . Immun . 46:122-127, 1984) and described as a hemolysin with enterotoxic and cytotoxic activity . The toxin was produced by only 63% of Aeromonas sobria strains and by 93% of Aeromonas hydrophila strains . Also, 54% of A . hydrophila strains produced another cytotoxic entity. J Clin Microbiol, 1986 Jun, 23(6), 1065 - 7 Growth of Aeromonas species on enteric agars; Desmond E et al.; The efficacy of eight routine enteric agars for supporting the growth of 32 strains of Aeromonas spp . (17 A . hydrophila strains, 8 A . sobria strains, and 7 A . caviae strains) was investigated . The plating efficiency of Aeromonas spp . on these media varied greatly (range, 0 to 100%), as did their colony size when compared with that on noninhibitory medium (5% sheep blood agar) . Plating efficiency on seven of these eight media appeared to be strain- and not species dependent . Overall, eosin-methylene blue and Hektoen enteric agars showed low plating efficiencies for A . hydrophila, whereas both A . sobria and A . caviae were severely inhibited on brilliant green agar . When all these species are considered collectively, deoxycholate, MacConkey, and xylose lysine deoxycholate appeared to be the most satisfactory routine agars for Aeromonas spp . recovery when used in conjunction with blood agar. J Clin Microbiol, 1986 Jun, 23(6), 1026 - 9 Phenotypic characteristics of Aeromonas species isolated from adult humans; George WL et al.; The phenotypic characteristics of 89 Aeromonas strains, most of which had been isolated from feces, were examined . Eighty-two percent of the isolates could be placed into one of four groups on the basis of five tests . The relationship of these groups to the three motile species of Aeromonas (Aeromonas caviae, A . hydrophila, and A . sobria) that have been isolated from humans is unclear . Because the means for identification of Aeromonas strains to the species level appear to be imprecise and because the role of each of these species in human diarrhea is unclear at this time, we recommend that identification of enteric Aeromonas isolates to the species level not be done routinely. Antimicrob Agents Chemother, 1986 Jun, 29(6), 992 - 6 Multiple low-level antibiotic resistance in Aeromonas salmonicida; Wood SC et al.; Mutants with multiple low-level antibiotic resistance were isolated from virulent wild-type Aeromonas salmonicida strains exposed to a low concentration of any one of several low-molecular-mass (approximately 635 daltons or less) antibiotics . Multiple resistance was toward beta-lactam compounds (penicillin G, ampicillin, cloxacillin), quinolones (flumequine, oxolinic acid, nalidixic acid), tetracyclines, chloramphenicol, and novobiocin . Susceptibilities of the mutants toward several higher-molecular-mass (greater than 700 daltons) hydrophobic or polycationic antibiotics such as rifampin, erythromycin, polymyxin B, and streptomycin sulfate were not affected . The mutants were obtained at frequencies suggesting point mutations . Outer membrane protein profiles, examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, revealed that all multiple low-level resistant mutants were deficient in a major protein of approximately 38.5 kilodaltons and contained a major protein of approximately 37 kilodaltons which was not present in significant amounts in the wild-type strains . In addition, these mutants lacked exoprotease activity . Furthermore, mutants isolated as deficient in exoprotease were found, with the exception of one avirulent strain, to exhibit multiple low-level antibiotic resistance and the outer membrane protein changes. Appl Environ Microbiol, 1986 Jun, 51(6), 1343 - 9 Electrostatic mechanism of survival of virulent Aeromonas salmonicida strains in river water; Sakai DK; The ecological mechanism of survival of Aeromonas salmonicida, the bacterial pathogen of fish furunculosis, in river water was investigated by laboratory-based experiments with two virulent strains (which were autoagglutinating) and two virulent strains (which were nonagglutinating) . A difference in net electrical charge of A . salmonicida cells was detected by electrophoresis; cells of the virulent strains were negative, whereas cells of the avirulent strains were positive . Despite the loss of viable cells within a week in distilled water and physiological saline (0.85% sodium chloride), the cells of the virulent strains survived for more than 15 weeks in the presence of diluted humic acid (10 micrograms/ml), tryptone (10 micrograms/ml), and cleaned river sand (100 g/100 ml of medium), but loss of viable cells occurred within 5 weeks in the absence of sand . The cells of the avirulent strains lost viability within 2 weeks with no relation to the presence of sand . Using ion-exchange columns, humic acid and the amino acids of tryptone were found to be anionic and cationic in water (pH 7.0), respectively . Sand particles had a high capacity to adsorb humic acid alone and amino acid-humic acid complexes . Thirty to fifty times the environmental concentration of amino acids (10 micrograms/ml) were accumulated on the surface of sand particles, thereby permitting only bacterial cells carrying net negative electrical charges (virulent cells) to survive for a long period on the surface of the sand particles . These electrostatic interrelationships among river sand, humic acid, and bacterial cells are closely implicated in the mechanism of long-term survival of virulent A . salmonicida in river sediments. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 93 - 105 The ontogeny of humoral immunity in rainbow trout, Salmo gairdneri; Tatner MF; The ontogeny of the humoral immune response to a 'thymus dependent' and a 'thymus independent' antigen, human gamma globulin (HGG) and Aeromonas salmonicida (AS) respectively, was investigated in the fry of rainbow trout, Salmo gairdneri, by direct immersion vaccination in the antigens (dose 5 mg/L HGG; 10(8) cells/ml AS; 30 minutes) at known ages/weights from 7 days post hatch, and at 1, 2, 3, and 4 months post hatch . Half the fry in each group were tested for antibodies 4 weeks after vaccination, the remainder were reimmunised and tested again after a further 4 weeks . Appropriate controls to test for tolerance induction and memory responses were included . The results indicate that fry are capable of mounting a humoral immune response very early in ontogeny . There is a period of 'unresponsiveness' which persists for longer against HGG, than against AS, though it was not thought to be tolerance as such . Memory could be detected to HGG in fry given a first immunisation at 2 months . The results are compared with preliminary experiments in which fry were first thymectomised 4 weeks before the first immunisation . In fry thymectomised at 1 month post hatch, and tested for primary and secondary responses at 2 and 3 months, the primary response to HGG is unaltered, but the secondary response is reduced . Both the primary and secondary response to AS is unaltered . When thymectomy is performed later, the effect on the secondary response to HGG is no longer apparent, but the primary response to AS is slightly reduced. Vet Immunol Immunopathol, 1986 Jun, 12(1-4), 181 - 92 Effects of direct immersion in antigen on immunological memory in young carp, Cyprinus carpio; Mughal MS et al.; The study asks whether, in fish, antigens encountered early in life can prime the immune system to yield memory responses on subsequent challenge with the same antigen and, if so, whether positive immunity or immunological tolerance is induced . The direct immersion method of vaccination was used to prime 4 week old carp, Cyprinus carpio, and was compared with priming by injection . Three different forms of antigen were used: the thymus dependent antigen, human gamma globulin (HGG) in soluble and in particulate (latex bound) form; also the putative thymus independent bacterin, formalin-killed Aeromonas salmonicida . The thymus dependent antigens were also used on 9 month old animals . In 4 week old carp, A . salmonicida vaccine delivered either by direct immersion or intraperitoneally (i.p.) yielded enhanced serum antibody levels and heightened proliferative responses in the lymphoid tissue of the spleen and kidney . Latex-bound HGG applied by direct immersion was found to partially suppress secondary antibody production while still eliciting enhanced proliferation . The decrease in antibody production following direct immersion priming of young fish with latex-bound HGG was not nearly as marked as the tolerance induced following priming with latex-bound HGG by the i.p . route and, unlike the tolerance induced by the injection route, may possibly still occur in older fish . When HGG was applied to young carp in soluble form by direct immersion it was ineffective and failed to influence memory induction . This is in contrast to the antibody tolerance, accompanied by an enhanced proliferative response following challenge, which resulted from administration of the soluble antigen by injection in the young fish . The status of the immune system in these antibody-tolerant fish is still far from clear . This highlights the need for further investigation of the role of cell-mediated reactions and local immunity in the immune responses of fish. Appl Environ Microbiol, 1986 Jun, 51(6), 1309 - 13 Differential partition of virulent Aeromonas salmonicida and attenuated derivatives possessing specific cell surface alterations in polymer aqueous-phase systems; Van Alstine JM et al.; Two-polymer aqueous-phase systems were used to compare via partitioning the surface properties of strains of the fish pathogen Aeromonas salmonicida which differed in their ability to produce the surface protein array known as the A layer and in their ability to produce smooth lipopolysaccharide . In these two-phase systems, biological particles are known to partition between the phases in a manner related to a variety of surface properties, including hydrophobicity, charge, and lipid composition . Both the presence of the superficial protein layer and the O polysaccharide chains of lipopolysaccharide were shown to play an important role in the partitioning behavior of A . salmonicida cells . The presence of the A layer, which is crucial to the virulence of A . salmonicida, appeared to decrease the surface hydrophilicity of this pathogen and to increase, in a somewhat specific manner, its surface affinity for fatty acid esters of polyethylene glycol . The ability of two-polymer aqueous-phase systems to differentially partition A . salmonicida cells on the basis of differences in surface architecture suggests their general usefulness for the analysis of surface properties important in bacterial virulence and should permit their use in the selection of strains and mutants exhibiting specific surface characteristics. Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi, 1986 May, 19(2), 124 - 36 Comparative study of the biotype, hemolysin-producing capability and antibiogram of the aquatic and the clinical strains of Aeromonas hydrophila; Tsai WC et al.; One hundred and seventy-two Aeromonas hydrophila strains were isolated from aquatic hosts including fish, turtle, frogs, shellfish and water itself . The aquatic organisms were compared with 45 clinical strains with regard to biotype, hemolysin, and antibiogram . The carrier rate of A . hydrophila in the aquatic environment was 61.7% . Of the aquatic strains 51% were hemolysin producers, equivalent to a capability for producing enterotoxin . The hemolysin-producing capability of aquatic strains was not significantly different from that of the clinical strains . The main code numbers or biotypes of aquatic strains were 3265 (29.4%), 3065 (17.5%), 7065 (9.6%), 7265, 3225 (each 8.5%) . The main code number or biotypes of clinical strains were 3265 (36.1%), 3065 (9.8%), 7261 (6.6%), 2265, 3261 and 6241 (each 4.9%) . Analysis of the antibiotic susceptibility pattern of both aquatic and clinical A . hydrophila strains using the microbroth dilution method showed that there is no significant difference in antibiotic susceptibility . Most aquatic and clinical strains were highly susceptible to tobramycin, gentamicin, amikacin, cefuroxime, piperacillin, cefotaxime and cefoperazone . Most strains of aquatic A . hydrophila were highly susceptible to cefamandole and chloramphenicol; however, clinical strains were only moderately susceptible to the same drugs . Most aquatic and clinical strains were highly resistant to ampicillin, and moderately resistant to sulbenicillin . Clinical strains were moderately resistant to cephapirin; however, aquatic strains were moderately susceptible to cephapirin . Based on the above findings, we may considered aquatic environment be, at least partially, the source of clinical strains . Furthermore, biotypes of aquatic A . hydrophila do not correspond to antibiogram or hemolysin-producing patterns. J Bacteriol, 1986 Apr, 166(1), 120 - 7 Two patterns in the Aeromonas salmonicida A-layer may reflect a structural transformation that alters permeability; Stewart M et al.; Electron micrographs of negatively stained regular surface layers (A-layers) of Aeromonas salmonicida showed two square patterns having p4 symmetry . Computer image processing demonstrated that, at a resolution of 2.3 nm, both square arrays were composed of two different morphological units arranged alternatively to give a face-centered lattice in which the four nearest neighbors of each unit were the other type of unit . The lattice constant was slightly but significantly different in the two patterns, and the orientation of one of the two morphological units changed by about 20 degrees between patterns . These patterns were probably not derived from different strains present in the preparation, since both were seen in material that appeared to come from a single layer . This and the difference in lattice constant made it unlikely that they represented different sides of the A-layer . However, it is possible that the two patterns may reflect a structural transformation of the layer . In this respect, it is interesting that the rotation of one morphological subunit changed the size of the gaps between units in the layer . This raised the possibility that the transformation could be related to a change in permeability of the A-layer, possibly analogous to that proposed for gap junctions in eucaryotic cells. Appl Environ Microbiol, 1986 Mar, 51(3), 668 - 70 Heme requirement for growth of fastidious atypical strains of Aeromonas salmonicida; Ishiguro EE et al.; The growth of fastidious atypical strains of the fish pathogen Aeromonas salmonicida on both solid and liquid media was dependent specifically on a source of heme which was apparently required for initiation of growth at low inoculum densities . Thus, hemin enhanced the plating efficiencies of such strains on solid medium and significantly reduced their inoculum-size-dependent lag times in broth . The heme requirement could also be satisfied by hematoporphyrin and, less effectively, by hemoglobin . Since the requirement was a stable property of all 17 strains tested, it may prove to be another taxonomic criterion by which the atypical strains can be differentiated from the typical strains of A . salmonicida. J Clin Microbiol, 1986 Mar, 23(3), 595 - 9 Prevalence, species differentiation, and toxigenicity of Aeromonas strains in cases of childhood gastroenteritis and in controls; Figura N et al.; In a 1-year period (January to December 1984), Aeromonas strains were isolated from feces of 21 of 561 (3.7%) children with gastroenteritis and from 12 of 576 (2.1%) children without intestinal disturbances (controls) . The difference between the two isolation rates was not significant (X2 = 2.2; P greater than 0.05) . In five cases of illness other intestinal pathogens were isolated together with Aeromonas in the same stool sample . A total of 39 Aeromonas strains were detected since in some cases aeromonads with different biochemical characteristics were obtained from the same stool sample . Of the 39 Aeromonas isolates, 6 strains (5 from patients) were Aeromonas hydrophila, 5 strains (3 from patients) were Aeromonas sobria, and 26 strains (18 from patients) were Aeromonas caviae; 2 strains isolated from controls did not ferment sucrose and were considered a distinct group of Aeromonas . We found no significant difference between the prevalence of each of these species from patients and the prevalence from controls . We found no significant difference in the prevalence of enterotoxin-producing strains (suckling mouse model), cytotoxin-producing strains (HEp-2 cell model), or hemolysin-producing strains (rabbit erythrocyte model) between patients and controls . In our geographical region there is no evidence that Aeromonas species are primary intestinal pathogens in children. Am J Clin Pathol, 1986 Mar, 85(3), 330 - 6 The clinical significance of stool isolates of aeromonas; Travis LB et al.; The purpose of this study was to determine the clinical significance of different Aeromonas species isolated from stool . During a 17-month period, 29 strains of Aeromonas were isolated and identified to species with the following results: 22, A . caviae, 5, A . hydrophila, and 2, A . sobria . Clinical significance was determined independently of knowledge of speciation result . Nineteen isolates represented colonization, implying that Aeromonas can be recovered from the gastrointestinal tract without causing primary disease . The remaining 10 isolates were of indeterminate significance and may have played a role in infection, but pertinent tests to rule out other enteric pathogens had not been done . A correlation between species and clinical significance could not be established . Antimicrobial susceptibility testing was performed on the 29 isolates . A . caviae showed an unexpected resistance to cefazolin and cefoxitin, whereas representatives of all three species displayed resistance to trimethoprim/sulfamethoxazole. Can J Microbiol, 1986 Jan, 32(1), 1 - 3 The interaction of complement components with Aeromonas species; Brenden RA et al.; The interaction of seven serum-sensitive Aeromonas strains with the complement system was investigated using a 2-h quantitative assay . Of the strains tested, four isolates activated both the alternative and classical pathways, two activated only the alternative pathway, and one strain was sensitive to the bactericidal action of complement through the classical pathway only . Two of the four Aeromonas caviae strains were such efficient activators of the complement system that when challenged with human sera deficient in normal concentrations of C3 and C4, they were still subject to complement-mediated bacterial lysis . This phenomenon, in conjunction with previous studies on complement activation by Aeromonas spp., may help account for the decreased incidence observed of systemic disease caused by Aeromonas caviae. Rev Argent Microbiol, 1986, 18(3-4), 121 - 6 {Aeromonas hydrophila in waters of Lake San Roque and its tributaries}; Fracchia de Salvay Y; The presence of Aeromonas hydrophila in 72 samples of water of Lake San Roque and two rivers that flow into it, situated in Punilla Valley, Cordoba was investigated . Water-peptone Alkaline (enrichment medium) and Rippey Cabelli Agar without ampicillin (selective and differential medium for Aeromonas hydrophila) were used for isolation . The colonies obtained were assayed by oxidase test and subsequent oxidation-fermentation of Hugh Leifson, motility, urease, mannitol and trehalose fermentation, ornithine and lysine decarboxylation . Voges Proskauer and gas production from glucose and glycerol . Aeromonas hydrophila was isolated in 13% of water samples obtained in days with high temperature . Although this finding is not alarming, its presence should be taken into account because of its potential pathogenesis. Circ Shock, 1986, 20(4), 291 - 7 Prostacyclin and thromboxane A2 in septic shock: species differences; Yellin SA et al.; Prostacyclin and thromboxane A2 have been implicated as mediators of septic shock . Correlations between the human prostanoid response to sepsis and experimental paradigms are poorly understood . The purpose of this study was to compare changes in plasma levels of prostaglandin 6-keto-F1 alpha (PGI) and thromboxane B2 (TxB) during septic shock in Sprague-Dawley rats, domestic pigs, mongrel dogs, and man . Severe sepsis followed by septic shock (systolic BP less than 90 mmHg) was induced in rats by inoculation of 1.0 X 10(9) Aeromonas hydrophila, in pigs by graded IV infusion of 1.0 X 10(9)/ml A . hydrophila; and in dogs by an IV bolus injection of 5.0 X 10(9)/ml Escherichia coli . Plasma PGI and TxB (pg/ml) were measured by radioimmunoassay in control, septic, and septic shock experimental blood samples, and in normal controls, severly septic, and septic shock (systolic BP less than 90 mmHg) S.I.C.U . patients . Control, septic, and septic shock TxB levels in the dog and the pig were significantly greater than in the rat and man . PGI levels in the dog were significantly greater than in other species . TxB increased significantly in murine sepsis and PGI increased significantly in sepsis and septic shock . TxB increased during porcine sepsis and septic shock . In man, both PGI and TxB were significantly increased in severe sepsis, compared to normal controls, but only PGI was significantly higher in septic shock versus normotensive sepsis . Patterns of change in TxB/PGI ratios were similar for all species studied . Changes in PGI in the porcine septic experiments most closely paralleled those observed clinically. Vet Hum Toxicol, 1986, 28 Suppl 1, 45 - 54 Stress factors that can affect studies of drug metabolism in fish; Sommer CV et al.; The effects of environmental stress conditions on the defense response of rainbow trout following a four week exposure to subacute levels of un-ionized ammonia or temperatures 5 C above and 5 C below the temperature optimum (15 C) were investigated . These experimental studies can serve as a model to evaluate the metabolic response of fish to external agents (e.g., drugs, vaccines) under environmental conditions seen in the culture of fish . Blood and tissue immune parameters measured include hematocrits, antibody levels and differentiation of white blood cell populations in tissue imprints of the anterior kidney . These analyses were compared to the growth parameter, average percent weight gain . Fish given primary and secondary immunization with a bacterial vaccine (Aeromonas hydrophila) were exposed to sublethal concentrations of un-ionized ammonia of 0.2, 0.3 or 0.4 mg/ml . Fish exposed to the higher concentrations of ammonia showed a decrease in growth compared to control fish . Several significant changes were observed in the leukocytes of the anterior kidney at the various concentrations of ammonia tested . A decrease in antibody titers to A hydrophila was seen at the two higher concentrations of ammonia . In a second study, the effects of non-optimum temperature conditions (10 C and 20 C) were compared with an optimum temperature (15 C) . Fish held at sub-optimum temperatures had significantly lower hematocrits than the control fish maintained at 15 C . Several significant changes were also seen in the anterior kidney leukocytes . Antibody titers to A hydrophila were significantly lower at the end of the stressing period in the trout maintained at 10 C compared to the immunized controls at 15 C . In contrast, fish held at 20 C had significantly higher antibody titers than did the immunized controls . Compared to controls, fish growth was increased at 10 C and decreased at 20 C . These studies confirm that environmental factors can induce stress and affect the metabolism and health of the fish. J Antimicrob Chemother, 1986 Jan, 17(1), 45 - 50 Beta-lactamases with high activity against imipenem and Sch 34343 from Aeromonas hydrophila; Shannon K et al.; Two groups of inducible beta-lactamases were found among nine isolates of Aeromonas hydrophila . Five isolates produced enzymes with high activity against the penem Sch 34343 and the carbapenem imipenem: the enzymes from some of these isolates also had activity against penicillin, ampicillin, carbenicillin, cephaloridine and cephalexin but one isolate produced an enzyme with no detectable activity against cephalosporins . The other four isolates produced typical 'cephalosporinases' with activity against cephaloridine and cephalexin but not against cefuroxime, cefotaxime, penicillins, imipenem or Sch 34343. Vet Hum Toxicol, 1986, 28 Suppl 1, 11 - 7 Antimicrobials and fish: a review of drugs used to treat bacterial diseases of channel catfish and rainbow trout; Herman RL et al.; The principal bacterial diseases of cultured rainbow trout (Salmo gairdneri) and channel catfish (Ictalurus punctatus), and the antibacterials used in their treatment are briefly reviewed . Gram-negative bacteria predominate, and oxytetracycline is effective in treatment of infections induced by them . The only antibacterials now registered by the US Food and Drug Administration are sulfamerazine for the treatment of furunculosis in trout, and oxytetracycline for the treatment of furunculosis in salmonids and Aeromonas and Pseudomonas infections in salmonids and catfish . Registration 9/50 is now complete for the potentiated sulfonamide Romet-30 for controlling furunculosis in salmonids . Studies on the metabolism of antibacterials in fishes are limited, and are primarily concerned with tissue residue and elimination rate. Bull Soc Pathol Exot Filiales, 1986, 79(4), 447 - 57 {Diarrhea caused by Aeromonas in Ivory Coast}; Dosso M et al.; The authors drawn epidemiological, clinical conclusions, and the geographical data concerning the diarrheas with Aeromonas in Ivory-Coast . The results relate to a study realized from January 1982 to July 1985 . Out of the 1,594 excrements 627 germes have been isolated and among which 153 strains of aeromonas if for instance 24.4% of the whole germs . Aeromonas caviae is the most frequent species (50%) compared to 27.3% for Aeromonas sobria, and 22.7% for Aeromonas hydrophila. Arch Intern Med, 1985 Dec, 145(12), 2207 - 11 Aeromonas-related diarrhea in adults; George WL et al.; We have reviewed the incidence of Aeromonas in patients with enteric disease at our hospital and found it to be the highest of any potential enteric pathogen . Eighty adult patients with diarrhea had Aeromonas isolated from feces, and in 73 Aeromonas was the only potential bacterial or parasitic pathogen detected . The spectrum of illness in patients with Aeromonas-related diarrhea ranged from acute, self-limited diarrhea to a chronic, indolent diarrheal illness . Sixteen percent (13/80) of the patients had evidence of colitis noted during sigmoidoscopy or colonoscopy . Our data (and those from other studies) indicate that Aeromonas is relatively common in the feces of adults with diarrhea; they also indicate the need for prospective, controlled clinical and bacteriological studies to determine whether or not Aeromonas is an important enteric pathogen in adults. J Clin Microbiol, 1985 Dec, 22(6), 1061 - 2 Identification of hydroxy fatty acids in Aeromonas hydrophila, Aeromonas sobria, and Aeromonas caviae; Canonica FP et al.; Gas-liquid chromatographic analysis of fatty acid methyl esters obtained from clinical isolates of Aeromonas hydrophila, A . sobria, and A . caviae revealed the presence of two hydroxy fatty acid species, 3-OH 12:0 and 3-OH 14:0. J Bacteriol, 1985 Dec, 164(3), 1233 - 7 Congo red agar, a differential medium for Aeromonas salmonicida, detects the presence of the cell surface protein array involved in virulence; Ishiguro EE et al.; Strains of the fish pathogen Aeromonas salmonicida which possess the cell surface protein array known as the A-layer (A+) involved in virulence formed deep red colonies on tryptic soy agar containing 30 micrograms of Congo red per ml . These were readily distinguished from colorless or light orange colonies of avirulent mutants lacking A-layer (A-) . The utility of Congo red agar for quantifying A+ and A- cells in the routine assessment of culture virulence was demonstrated . Intact A+ cells adsorbed Congo red, whereas A- mutants did not bind Congo red unless first permeabilized with EDTA . The dye-binding component of A+ cells was shown to be the 50,000-Mr A-protein component of the surface array . Purified A-protein avidly bound Congo red at a dye-to-protein molar ratio of about 30 by a nonspecific hydrophobic mechanism enhanced by high salt concentrations . Neither A+ nor A- cells adsorbed to Congo red-Sepharose columns at low salt concentrations . On the other hand, A+ (but not A-) cells were avidly bound at high salt concentrations. J Bacteriol, 1985 Dec, 164(3), 1332 - 6 Porphyrin binding by the surface array virulence protein of Aeromonas salmonicida; Kay WW et al.; Congo red binding by virulent A-layer-containing (A+) and avirulent A-layer-deficient (A-) strains of Aeromonas salmonicida was examined . Congo red binding to A+ cells was enhanced by salt and thus hydrophobically driven, but at low Congo red concentrations binding was salt independent . Congo red was bound by A+ cells by a kinetically distinct mechanism (Kd, 0.25 microM) which was absent in A- isogenic strains . Purified A-layer protein ("A protein") protein A also bound Congo red with similar affinity (Kd, 0.40 microM) . Congo red binding was structurally specific; it was not influenced by a wide variety of compounds including amino acids and nucleotides and only weakly inhibited by structurally similar dyes . However, protoporphyrin IX and hemin were strong competitive inhibitors of Congo red binding . Protoporphyrin and hemin were bound only by A+ strains (KdS of 0.41 and 0.63 microM, respectively) . Furthermore, binding of these porphyrins was strongly inhibited by Congo red but weakly inhibited by hematoporphyrin . Purified A protein also bound protoporphyrin IX and hemin with affinities similar to those of A+ cells (KdS of 0.94 and 0.41 microM, respectively. Southeast Asian J Trop Med Public Health, 1985 Dec, 16(4), 532 - 3 Purpura fulminans produced by Aeromonas hydrophila: a case report; Thisyakorn U et al.; A case of purpura fulminans produced by Aeromonas hydrophila in a twelve year-old Thai boy was reported . The patient also had aplastic anemia which facilitated the severity of disease . He died despite appropriate antimicrobial therapy. J Gen Microbiol, 1985 Dec, 131 ( Pt 12), 3385 - 91 Comparative electrophoretic profiles of esterases, and of glutamate, lactate and malate dehydrogenases, from Aeromonas hydrophila, A . caviae and A . sobria; Picard B et al.; Esterases, and glutamate, lactate and malate dehydrogenases of 64 Aeromonas hydrophila, A . caviae and A . sobria strains, were analysed by polyacrylamide agarose gel electrophoresis and by thin layer isoelectrofocusing . On the basis of the isoelectric points of malate dehydrogenase from the three species and the mobility of lactate dehydrogenase from A . sobria, 8 species specific zymotypes were defined: three for A . hydrophila strains, three for A . caviae strains and two for A . sobria strains . These zymotypes correlated with previously established DNA hybridization groups . The other electrophoretic data were found to be less useful for distinction between A . hydrophila and A . sobria strains, but supported differentiation into zymotypes for A . caviae strains . The two-dimensional electrophoretic profile established by plotting isoelectric point against electrophoretic mobility of the major esterase illustrated the degree of enzyme polymorphism among the strains of the three species . Variation in electrophoretic patterns within A . hydrophila and A . caviae might provide useful epidemiological markers. J Clin Microbiol, 1985 Nov, 22(5), 888 - 90 Media for the isolation of Aeromonas hydrophila; Kay BA et al.; Isolation rates of Aeromonas hydrophila from stool samples of symptomatic and asymptomatic individuals were examined for several common enteric media . Sheep blood agar with 10 micrograms of ampicillin per ml, preceded by overnight enrichment in alkaline peptone water, yielded 2.6 times the number of isolates as the other media examined and is recommended for the isolation of A . hydrophila from humans. J Clin Microbiol, 1985 Nov, 22(5), 854 - 5 Cephalothin susceptibility as a potential marker for the Aeromonas sobria group; Janda JM et al.; Fifty-four motile Aeromonas strains, composing the three currently recognizable species, were tested for susceptibility to cephalothin by broth dilution and disk agar diffusion assays . Cephalothin susceptibility was significantly associated with Aeromonas sobria (P less than 0.001) and may be an additional phenotypic marker useful in the identification of this species. J Biol Chem, 1985 Oct 25, 260(24), 13154 - 62 The slow, tight binding of bestatin and amastatin to aminopeptidases; Wilkes SH et al.; Bestatin reversibly inhibits Aeromonas aminopeptidase (EC 3.4.11.10) in a process that is remarkable for its unusual degree of time dependence . The binding of bestatin by both Aeromonas aminopeptidase and cytosolic leucine aminopeptidase (EC 3.4.11.1) is slow and tight, with Ki values (determined from rate constants) of 1.8 X 10(-8) and 5.8 X 10(-10) M, respectively . In contrast, microsomal aminopeptidase (EC 3.4.11.2) binds bestatin in a rapidly reversible process with a Ki value of 1.4 X 10(-6) M . Kinetic analysis of the slow inhibition observed is facilitated by the use of a variety of experimental treatments, primarily measurements made during pre-equilibrium; however, careful selection of conditions permits use also of steady state observations . When titrated with bestatin, 1 mol of cytosolic leucine aminopeptidase (containing 6 g atoms each of zinc and manganese) is rendered 80% inactive by 1 mol of inhibitor, thus suggesting that enzymatic activity depends on one active site/hexamer; titration of Aeromonas aminopeptidase by bestatin reveals a 1:1 stoichiometry . Amastatin inhibits all three aminopeptidases through the mechanism of slow, tight binding with Ki values ranging from 3.0 X 10(-8) to 2.5 X 10(-10) M . This behavior of microsomal aminopeptidase contrasts sharply with its rapidly reversible inhibition by bestatin . The slow, tight binding observed with five of the six aminopeptidase-inhibitor pairs investigated suggests the formation of a transition state analog complex between the enzyme and inhibitor . Physical evidence consistent with this possibility was provided by the observation that both bestatin and amastatin perturb the absorption spectrum of cobalt Aeromonas aminopeptidase. Infect Immun, 1985 Oct, 50(1), 62 - 5 Lack of correlation between known virulence properties of Aeromonas hydrophila and enteropathogenicity for humans; Morgan DR et al.; Five strains of Aeromonas hydrophila were selected for use in volunteer challenge trials . All five strains produced cytotoxin, hemolysin enterotoxin, lysine decarboxylase, acetylmethylcarbinol, and DNase . Two strains hydrolyzed esculin . All strains produced purulent hemorrhagic fluid accumulation in rabbit ileal loops, but failed to induce keratoconjunctivitis in guinea pigs . None of the strains produced mannose-resistant hemagglutinins . In challenge studies, diarrhea was demonstrated in only 2 of 57 human volunteers with doses ranging from 10(4) to 10(10) CFU . One person experienced mild diarrhea with 10(9) CFU of strain 6Y . A second person developed moderate diarrhea with 10(7) CFU of strain 3647 . At higher doses, no diarrhea was seen in any of the volunteers . The other three strains (B158, SSU, 3284) failed to cause diarrhea and were not recovered from stools of volunteers . Additional virulence properties of A . hydrophila need to be sought before enteropathogenicity for humans can be established. Infect Immun, 1985 Oct, 50(1), 322 - 3 Demonstration of cholera toxin-related factor in cultures of Aeromonas species by enzyme-linked immunosorbent assay; Honda T et al.; The production of toxins by Aeromonas species was examined by the suckling mouse test, the hemolysin test, and the enzyme-linked immunosorbent assay with anticholera enterotoxin . A factor that was immunologically related to cholera enterotoxin was produced by 5 of 14 strains of Aeromonas hydrophila and 4 of 15 strains of Aeromonas sobria . Analysis by these assays and by a test for heat stability suggested that the factor differed from hemolysin and from toxin that was active in the suckling mouse test. J Gen Microbiol, 1985 Oct, 131 ( Pt 10), 2825 - 30 Molecular cloning and expression of a xylanase gene of alkalophilic Aeromonas sp . no . 212 in Escherichia coli; Kudo T et al.; A gene coding for a xylanase activity of alkalophilic Aeromonas sp . no . 212 (ATCC 31085) was cloned in Escherichia coli HB101 with pBR322 . Plasmid pAX1 was isolated from transformants producing xylanase, and the xylanase gene was located in a 6.0 kb Hind III fragment . The pAX1-encoded xylanase activity in E . coli HB101 was about 80 times higher than that of xylanase L in alkalophilic Aeromonas sp . no . 212 . About 40% of the enzyme activity was observed in the periplasmic space of E . coli HB101 . The pAX1-encoded xylanase had the same enzymic properties as those of xylanase L produced by alkalophilic Aeromonas sp . no . 212, but its molecular weight was lower (135 000 vs 145 000, as estimated by SDS polyacrylamide gel electrophoresis). J Bacteriol, 1985 Oct, 164(1), 263 - 9 Electrophoretic and immunochemical analyses of the lipopolysaccharides from various strains of Aeromonas hydrophila; Dooley JS et al.; Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the lipopolysaccharides isolated from strains of Aeromonas hydrophila which exhibit virulence for fish and which autoaggregate during growth in static broth culture . The lipopolysaccharides contained O-polysaccharide chains of homogeneous chain length . Two of the strains produced a surface protein array, and immunofluorescence and phage-binding studies revealed that a number of these O-polysaccharide chains of homogeneous length traversed the protein array and were exposed on the cell surface . Immunochemical analyses by immunoblotting, enzyme-linked immunosorbent assay, immunofluorescence, and immunoprecipitation with both polyclonal and monoclonal antibodies revealed the presence of three epitopes on the polysaccharide moiety of this homogenous-chain-length lipopolysaccharide morphotype . One epitope was species serogroup specific and reactive by immunoblotting . This epitope was not present on the heterogeneous-chain-length O polysaccharides of nonautoaggregating strains of A . hydrophila examined . The second epitope was conformation dependent and cross-reactive with an epitope on the homogenous-chain-length O polysaccharides of Aeromonas salmonicida lipopolysaccharide . The third epitope was recognized by a monoclonal antibody and appeared to involve that region of the A . hydrophila and A . salmonicida lipopolysaccharide molecules which contained the O-polysaccharide-core oligosaccharide glycosidic linkage. Biochemistry, 1985 Sep 24, 24(20), 5350 - 6 Spectral and kinetic studies of metal-substituted Aeromonas aminopeptidase: nonidentical, interacting metal-binding sites; Prescott JM et al.; Apoenzyme prepared by removal of the 2 mol of Zn2+/mol from Aeromonas aminopeptidase is inactive . Addition of Zn2+ reactivates it completely, and reconstitution with Co2+, Ni2+, or Cu2+ results in a 5.0-, 9.8-, and 10-fold more active enzyme than native aminopeptidase, respectively . Equilibrium dialysis and spectral titration experiments with Co2+ confirm the stoichiometry of 2 mol of metal/mol . The addition of only 1 mol of metal/mol completely restores activity characteristic of the particular metal . Interaction between the two sites, however, causes hyperactivation; thus, addition of 1 mol of Zn2+/mol subsequent to 1 mol of Co2+, Ni2+, or Cu2+ per mole increases activity 3.2-, 42-, or 59-fold, respectively . The cobalt absorption spectrum has a peak of 527 nm with a molar absorptivity of 53 M-1 cm-1 for 1 mol of cobalt/mol, which increases to 82 M-1 cm-1 for a second cobalt atom and is unchanged by further addition of Co2+ . Circular dichroic (CD) and magnetic CD spectra indicate that the first Co2+ binding site is tetrahedral-like and that the second is octahedral-like . Stoichiometric quantities of 1-butylboronic acid, a transition-state analogue inhibitor of the enzyme {Baker, J . O., & Prescott, J . M . (1983) Biochemistry 22, 5322}, profoundly affects absorption, CD, and MCD spectra, but n-valeramide, a substrate analogue inhibitor, has no effect . These findings suggest that the tetrahedral-like site is catalytic and the other octahedral-like site is regulatory or structural. Infection, 1985 Sep-Oct, 13(5), 228 - 30 Aeromonas caviae: an enteric pathogen? Altwegg M. Of the Aeromonas spp . isolated routinely in our laboratory from human feces, about two thirds represent Aeromonas caviae . In contrast to Aeromonas hydrophila and Aeromonas sobria, this species has been considered to be of little enteropathogenic significance due to the absence of known virulence factors . The clinical data presented here suggest a clinical significance of A . caviae, at least in some cases . As yet nothing is known about the pathogenic mechanisms involved. Infect Immun, 1985 Sep, 49(3), 756 - 9 Role of caseinase from Aeromonas salmonicida in activation of hemolysin; Titball RW et al.; Mutants of the bacterial fish pathogen Aeromonas salmonicida selected for inability to digest casein concomitantly lost hemolytic activity against horse erythrocytes under certain conditions . Mixtures of wild-type with mutant culture supernatants indicated that mutants produce an inactive precursor of a hemolysin which was activated by autogenous caseinase and, with less efficiency, by other serine proteases . Selective inhibition or repression of caseinase production in the wild-type strain also resulted in the production of an inactive precursor of a hemolysin . The precursor of hemolysin was also activated by a serum factor which appeared to exert its maximum effect at the bacterial surface or after entry into the bacterial cell . These results could affect the interpretation of studies evaluating the role of individual extracellular products in the pathogenesis of A . salmonicida infections. J Bacteriol, 1985 Sep, 163(3), 877 - 81 Synthesis, export, and assembly of Aeromonas salmonicida A-layer analyzed by transposon mutagenesis; Belland RJ et al.; Suicide plasmid pJB4JI, containing transposon Tn5 and phage Mu, was introduced into Aeromonas salmonicida 449 which produces a surface protein array known as the A-layer . Kanamycin-resistant exconjugants of 449 with altered ability to produce the A-layer were selected by virtue of their altered colonial morphology and color on medium containing the dye Congo red . Analysis of culture supernatants, periplasmic shock fluid, outer membranes, and whole-cell lysates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with a monoclonal antibody to A-protein revealed five classes of single-insertion mutations that affected the ability of cells to produce and export A-protein and to assemble the A-layer . These studies suggest that A-protein is produced from a single chromosomal gene . The subunits subsequently pass through the periplasm and across the outer membrane . At least one gene product is required for this export . Assembly of A-layer on the cell surface then requires the presence of O polysaccharide chains on the lipopolysaccharide . In one case, insertion of Tn5 resulted in loss of ability to produce both A-protein and lipopolysaccharide with O polysaccharide chains, suggesting that synthesis of A-protein and synthesis of lipopolysaccharide may involve coordinate regulation. Biochem Biophys Res Commun, 1985 Aug 15, 130(3), 1154 - 60 A transition-state-analog inhibitor influences zinc-binding by Aeromonas aminopeptidase; Baker JO et al.; The transition-state-analog inhibitor, 1-butaneboronic acid, markedly enhances the uptake of one g-atom of Zn2+ ions from a metal ion buffer system by Zn-depleted Aeromonas aminopeptidase . In contrast, a substrate-analog inhibitor, n-valeramide, does not perturb the equilibrium between Zn2+ ions and the enzyme in a metal ion buffer system . These results establish a role for metal ions in the binding of 1-butaneboronic acid to Aeromonas amino-peptidase and strongly imply that a bound Zn2+ ion interacts directly with substrate during catalysis but not during initial binding of substrate. Avian Dis, 1985 Jul-Sep, 29(3), 681 - 9 Prevalence and pathogenicity of Aeromonas hydrophila; Shane SM et al.; A field survey to determine the prevalence of Aeromonas hydrophila revealed a recovery rate of 8% in 141 specimens derived from a range of live, companion, and exotic avian species . The prevalence rate was similar in 240 sequential postmortem submissions during 1984 . Studies on the pathogenicity of A . hydrophila showed that 2-to-4-day-old chicks and turkey poults were highly susceptible to exposure via the subcutaneous, yolk-sac, and intracerebral routes, and mortality of 80-100% occurred within 48 hours of inoculation . Ducklings aged 4 days were generally refractory to exposure. J Gen Microbiol, 1985 Jul, 131 ( Pt 7), 1603 - 9 The purification and some properties of H-lysin from Aeromonas salmonicida; Titball RW et al.; H-lysin from Aeromonas salmonicida has been purified 1770-fold by freeze fractionation, ammonium sulphate precipitation, ion exchange chromatography and gel filtration chromatography . The purified material was predominantly H-lysin, devoid of detectable T-lysin, caseinase or gelatinase activity, although glycerophospholipid: cholesterol acyltransferase (GCAT) activity was present . The results suggested that H-lysin and GCAT activities were due to different extracellular products . Studies of the kinetics of haemolysis indicated that the H-lysin had an enzymic mode of action, and that initial erythrocyte damage appeared to precede lysis of the cell . The H-lysin was lethal to cultured rainbow trout gonad cells and leucocytes, but when it was injected intravenously in rainbow trout no pathological effects were observed. Antimicrob Agents Chemother, 1985 Jul, 28(1), 151 - 3 In vitro susceptibilities of Aeromonas hydrophila, Aeromonas sobria, and Aeromonas caviae to 22 antimicrobial agents; Motyl MR et al.; MICs of 22 antimicrobial agents for 60 strains of three Aeromonas species were determined by a microdilution method . The newer cephalosporins such as moxalactam, cefotaxime, and cefoperazone, the aminoglycosides, and chloramphenicol, tetracycline, nitrofurantoin, and trimethoprim-sulfamethoxazole inhibited most of the strains studied . Within the genus, A . hydrophila was more resistant than either A . caviae or A . sobria to the antibiotics tested. J Bacteriol, 1985 Jul, 163(1), 336 - 40 Activation of the hole-forming toxin aerolysin by extracellular processing; Howard SP et al.; A precursor-product relationship between aerolysin and a protein with a higher molecular weight was observed in culture supernatants of Aeromonas hydrophila . The larger protein was isolated by ammonium sulfate precipitation and ion-exchange and hydroxyapatite chromatography and compared with purified aerolysin . It was at least 250 times less hemolytic than aerolysin . Both proteins had the same amino acid sequence at the amino terminus . Cyanogen bromide fragments obtained from the two were identical except that each protein contained one unique fragment, and the fragment from the larger protein was 2,500 daltons larger than the fragment obtained from aerolysin . Treatment with trypsin or with an extracellular Aeromonas protease resulted in rapid conversion of the larger protein to a form corresponding in molecular weight and activity to aerolysin . The results indicate that aerolysin is exported to the culture supernatant as a protoxin which is later activated by proteolytic removal of a peptide from the C terminus. Jpn J Med Sci Biol, 1985 Jun, 38(3), 141 - 5 Peritrichous flagella in mesophilic strains of Aeromonas; Shimada T et al.; A total of 186 mesophilic strains of Aeromonas, comprising 151 A . hydrophila and 35 A . caviae, were tested for peritrichous flagella by Leifson's staining method . When incubated on solid medium for 18 hr at 22 C, peritrichous flagella were demonstrated in 28 (18.5%) of the 151 strains of A . hydrophila and in 6 (17.1%) of the 35 strains of A . caviae . The peritrichous flagella in these 34 mesophilic strains of Aeromonas were also observed by electron microscopy. J Clin Microbiol, 1985 Jun, 21(6), 909 - 13 Clinical and microbiological features of Aeromonas hydrophila-associated diarrhea; Agger WA et al.; The prevalence of Aeromonas hydrophila in stool specimens from patients with diarrhea was studied during 18 months . A . hydrophila was found in 1.1% of patients with diarrhea and in none of 533 control patients (P less than 0.02) . Cases were detected 1.5 times more often during the summer months than the winter months, and most occurred in children less than 2 years of age . Clinical features included fever greater than 38 degrees C (55%), abdominal cramps (35%), vomiting (25%), and duration of illness greater than 10 days (50%) . Detection of A . hydrophila in stools was facilitated by the use of sheep blood agar with 15 micrograms of ampicillin per ml which was flooded with oxidase reagent after growth . A cytotoxin was produced by 62% of the isolates, and the cytotoxic strains showed positive results in a hemolysin assay and a lysine decarboxylase reaction. Rev Infect Dis, 1985 May-Jun, 7(3), 314 - 20 Bacteremia caused by Aeromonas species in hospitalized cancer patients; Harris RL et al.; Bacteremia caused by Aeromonas species occurred in 24 hospitalized patients in a cancer institute during a 13-year period . All but one of these patients had a malignancy (88% had leukemia), and most were receiving chemotherapy for cancer . There was a striking numerical predominance of male patients (82%) . Unlike some previously described patients with infections due to this organism, none of these 24 patients had recently been exposed to fresh or salt water or to fish . The source of the infecting organism was thought to be endogenous--i.e., from patients' own gastrointestinal tracts . The clinical presentation of sepsis caused by this organism was nonspecific, except that ecthyma gangrenosum occurred in several patients . The overall mortality rate was 28% . The combination of an aminoglycoside and a cephalosporin is appropriate therapy for bacteremia caused by Aeromonas species. J Med Microbiol, 1985 Apr, 19(2), 273 - 7 Methods for the detection of haemagglutinins in Aeromonas; Crichton PB et al.; When grown in specified conditions and tested by a rocked-tile method, 40 of 41 isolates of two species of Aeromonas formed simultaneously at least two haemagglutinins among which were: (i) a mannose-sensitive haemagglutinins with strongest activity for guinea-pig or fowl red cells, formed by all of 31 isolates of A . hydrophila and 9 of 10 isolates of A . punctata ss . caviae; (ii) a haemagglutinin, sensitive to L-fucose or D-mannose, that reacted with human red cells and which was formed by all 41 isolates; and (iii) a mannose-resistant 'tanned red cell' haemagglutinin formed by 29 isolates of A . hydrophila and one isolate of A . punctata ss . caviae . Results emphasise that for the fullest possible identification of haemagglutinins produced by Aeromonas spp., strains should be cultured in a variety of conditions and tested with a wide range of red-cell species. Antimicrob Agents Chemother, 1985 Apr, 27(4), 479 - 84 Genetic and biochemical properties of AER-1, a novel carbenicillin-hydrolyzing beta-lactamase from Aeromonas hydrophila; Hedges RW et al.; A novel carbenicillin-hydrolyzing beta-lactamase has been discovered in a blood isolate of Aeromonas hydrophila . The enzyme resembles plasmid-determined carbenicillinases in substrate profile but differs in isoelectric point (pI 5.9) and molecular weight (22,000) and has been termed AER-1 . No evidence for a plasmid location could be obtained in A . hydrophila, but the AER-1 gene and resistance to chloramphenicol, streptomycin, and sulfonamide could be transferred by mobilization with IncP plasmids to Escherichia coli, where the gene cluster inserted at a unique chromosomal site . The linked resistances are similar to those found on multiresistance beta-lactamase transposons, but since insertion of the A . hydrophila gene cluster was site specific and recA+ dependent, the cluster is not a functional transposon. Infect Immun, 1985 Apr, 48(1), 146 - 52 Loss of virulence in a protease-deficient mutant of Aeromonas salmonicida; Sakai DK; The importance of extracellular protease production by Aeromonas salmonicida, the bacterial pathogen of fish furunculosis, was investigated with four virulent strains (which were autoagglutinative, hemagglutinative, resistant to fish serum, adhesive to fish tissue culture, protease positive, hemolysin positive, and leukocytolysin positive) and three avirulent strains (which were nonagglutinative, nonhemagglutinative, sensitive to serum, nonadhesive, protease positive, hemolysin positive, and leukocytolysin positive) . A protease-deficient mutant (NTG-1) was induced by mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine from virulent strain A-7301, showing protease production, which was common to the two strain groups . Strain NTG-1 showed loss of virulence in determinations of 50% lethal doses, although it remained autoagglutinative, hemagglutinative, serum resistant, adhesive, hemolysin positive, and leukocytolysin positive . A protease fraction separated from extracellular products of strain A-7301 by DEAE-cellulose column chromatography had the capacity to produce skin lesions (furuncles) and high mortality in sockeye salmon . A comparable protein fraction from extracellular products of NTG-1 resulted in no protease activity and no pathological effects on the fish . The avirulent strains were eliminated from rainbow trout in a short time, whereas the virulent strains (including A-7301) were highly infective and proliferated in hosts . NTG-1 preserved its infectivity, but fish showed no signs of disease and no mortality . These findings indicate that extracellular protease is a major virulence factor and that protease production in the host is closely implicated in the pathogenesis of fish furunculosis. J Bacteriol, 1985 Mar, 161(3), 1118 - 24 Protein export by a gram-negative bacterium: production of aerolysin by Aeromonas hydrophila; Howard SP et al.; The synthesis and export of aerolysin, an extracellular protein toxin released by the gram-negative bacterium Aeromonas hydrophila, was studied by pulse-labeling with {35S}methionine . The toxin was synthesized as a higher-molecular-weight precursor . This was processed cotranslationally, resulting in the appearance within the cell of the mature protein, which was then exported to the supernatant . Precursor aerolysin accumulated in cells incubated in the presence of carbonyl cyanide m-chlorophenyl hydrazone, a substance which also inhibited the export of mature aerolysin from the cell . The entrapped mature toxin could not be shocked from the cells, although it could be digested by protease applied to shocked cells . The toxin was processed and translocated across the inner membrane of pleiotropic export mutants and accumulated in the periplasm . The results indicate that more than one step is required for the export of the protein and that aerolysin does not cross the inner and outer membranes simultaneously. J Hosp Infect, 1985 Mar, 6(1), 75 - 80 Aeromonas hydrophila in chlorinated water supplies; Millership SE et al.; Methods for the isolation and enumeration of Aeromonas hydrophila in water supplies are described . Examination of 286 chlorinated samples collected between July and October showed that 19% of otherwise uncontaminated waters contained Aerom . hydrophila, rising to 71% of those from which Escherichia coli was isolated . The isolation rate during January and February was only 7% for all samples . On the basis of these results, tap water is a likely source of the aeromonads found in human intestinal flora. Ann Biol Clin (Paris), 1985, 43(5), 725 - 31 {Isolation of Aeromonas hydrophila in diarrhea . Characterization of enterotoxinogenic strains and clinical relations}; Brauer C et al.; Aeromonas hydrophila is isolated from diarrhoea specimens with increasing frequency . The interest in this organism at the present time is related to the fact that it can produce a number of toxins, in particular alpha and beta cytotoxic haemolysins, an enterotoxin and various enzymes . The authors determined the frequency of isolation of this organism and tested the haemolytic, cytotoxic and enterotoxic effects of culture filtrates in all of the stool specimens received in their laboratory over a period of 9 months . At the same time, the clinical context was defined in order to demonstrate a relation between the aptitude of the strains to produce toxins and the presence of diarrhoea . The frequency of isolation of A . hydrophila was 0.88 per cent, which corresponds to 67 strains . 38 strains presented a haemolytic and/or enterotoxic activity, i.e . 57 per cent of the strains isolated . In diarrhoeal stools, 67 per cent of the A . hydrophila isolated produced at least one of the toxins, while in the group of patients without diarrhoea, only 38 per cent of the strains isolated produced toxins . The results obtained reveal a statistically significant correlation between the production of cytotoxic haemolysin and the presence of diarrhoea . In contrast, there was no correlation between the production of enterotoxin and the presence of diarrhoea . Twenty of the 67 strains ware isolated from children under the age of 2 years . In 40 per cent of cases, no other aetiology could be found for the diarrhoea, apart from the isolation of A . hydrophila.(ABSTRACT TRUNCATED AT 250 WORDS) Cell Tissue Res, 1985, 242(3), 491 - 8 Antigen localization in the lymphoid organs of carp (Cyprinus carpio); Lamers CH et al.; A brief morphological description is given of the spleen, head kidney and trunk kidney, the three peripheral lymphoid organs of carp . An antigen-localization study was carried out using Aeromonas hydrophila (a cellular bacterial antigen) and an indirect immunofluorescence test . Examination of the lymphoid organs at various times after injection (up to 12 months) showed that antigen was at first present in splenic ellipsoids and in solitary phagocytic cells in the spleen, head and trunk kidney . Later on, the antigen was gradually concentrated in or near melano-macrophage centres in all the organs studied . By this time, it had disappeared from the splenic ellipsoids, and the number of solitary A . hydrophila-immunoreactive cells had also decreased . At a later stage, antigen was located extracellularly at the membrane of cells in and around the melano-macrophage centres, and it remained so for a full year . No antigen was detected in the lymphoid organs following a bath immunization. Dev Comp Immunol, 1985 Winter, 9(1), 65 - 75 Humoral response and memory formation in carp after injection of Aeromonas hydrophila bacterin; Lamers CH et al.; The humoral immune response of carp (Cyprinus carpio) upon a bacterial fish pathogen Aeromonas hydrophila was studied in relation to memory formation . After a single intramuscular (i.m.) injection of formalin killed A . hydrophila cells (F-Ah), maximum serum Ab (Ab) titers were observed at day 20 . Distinct titers were still seen at day 360 in the groups injected with a medium or high antigen (Ag) dose (10(7) respectively 10(9) F-Ah) . The effect of a second immunization with a high Ag dose was studied in fish primed 1, 3, 8 or 12 months earlier with 10(5), 10(7) or 10(9) F-Ah . The height of the secondary Ab response was positively correlated with the height of the priming Ag dose . Challenge with a low Ag dose (10(6) F-Ah) gave the best results with 10(7) F-Ah primed animals . The highest secondary responses were obtained with combinations of corresponding priming and challenge dosages . It is concluded that fish are able to form immunological memory to this bacterial Ag . However, optimal memory levels are reached after a relative long period (3-8 months). J Infect, 1985 Jan, 10(1), 32 - 7 Pathogenicity of aeromonas; Brook I et al.; The ability of 15 Aeromonas sobria and 9 Aeromonas hydrophila isolates to cause subcutaneous lesions was tested . An inoculum of 10(11) colony forming units/l was injected subcutaneously into mice . Surviving animals developed a subcutaneous abscess and/or localised skin sloughing and loss of hair (alopecia) . An abscess was induced by all nine A . hydrophila isolates and by three of the 15 A . sobria isolates . The induction of local epidermal sloughing and loss of hair followed challenge with either A . hydrophila or A . sobria and correlated with the organisms' lethality for mice and their cytotoxicity in the Y-I adrenal cell assay . Local epidermal sloughing was not induced by the media used for growing the organisms or by sonicated cells of the isolates . The ability to cause epidermal sloughing was lost by incubating viable cells at 45 degrees C for 35 minutes . These yet unreported in vivo features of Aeromonas sp . may be useful in studies of the pathogenicity of the species as well as for rapid assay of toxicity of strains. J Bacteriol, 1985 Jan, 161(1), 463 - 5 Phospholipids and lipopolysaccharide of Aeromonas hydrophila; Howard SP et al.; The phospholipids and lipopolysaccharide of Aeromonas hydrophila were characterized . Phosphatidylethanolamine and phosphatidylglycerol were the major phospholipid components . The outer membrane contained more phosphatidylethanolamine and less phosphatidylglycerol than the inner membrane, and the phospholipids of the outer membrane contained a higher proportion of saturated fatty acids . Only four fatty acids (C14:0, C16:0, C16:1, and C18:1) were found in the phospholipids . The lipopolysaccharide of A . hydrophila did not contain the eight-carbon sugar 3-deoxyoctulosonic acid nor did it contain C16:0, both of which are typical constituents of the lipopolysaccharide of many other species. Circ Shock, 1985, 16(4), 395 - 404 Thromboxane, prostacyclin, and the hemodynamic effects of graded bacteremic shock; Slotman GJ et al.; This study investigates the interaction of thromboxane, prostacyclin, and the hemodynamic dysfunction of graded bacteremia . Arterial, venous, and pulmonary artery catheters were inserted into eight adult female pigs under barbiturate anesthesia . After a 60-min control period Aeromonas hydrophila (1.0 X 10(9)/ml) was infused intravenously at 0.2 ml/kg/hr, increasing gradually to 4.0 ml/kg/hr at 4 hr . Hemodynamic measurements, blood gases, and radioimmunoassay of thromboxane B2 (TxB) and prostaglandin 6-keto-F1 (PGI) were performed during the control period, at 10, 20, 30, 45, 60, 75, and 90 min of bacteremia and at 30-min intervals thereafter . During the bacterial infusion, cardiac index (CI), mean arterial pressure (MAP), paO2, pvO2, stroke volume (SV), and left ventricular stroke work (LVSW) decreased significantly, and pulmonary vascular resistance (PVR), pulmonary artery pressure (PAP), and intrapulmonary shunt (Qs/Qt) increased significantly . TxB was significantly increased at 30 min and remained elevated thereafter . PGI did not rise above control levels until after 240 min of bacterial infusion . TxB cross-correlated most frequently with CI, PVR, SV, paO2, and Qs/Qt, changes in TxB preceding the other variables by 0-60 min . PGI cross-correlated significantly with MAP, LVSW, CI, paO2, and Qs/Qt, changes in PGI preceding MAP, LVSW, and CI by 0-60 min, but following paO2 and Qs/Qt by 30-60 min . TxB is increased early in graded bacteremia and appears related to cardiorespiratory dysfunction . PGI increases late in graded bacteremia, following the onset of respiratory failure, and may mediate the arterial hypotension of septic shock. Dev Comp Immunol, 1985 Spring, 9(2), 251 - 60 Eosinophilic granular cells (EGC) and histamine responses to Aeromonas salmonicida toxins in rainbow trout; Ellis AE; The function of eosinophilic granular cells (EGCs) in salmonids is unknown . In a previous study of the pathogenesis of A . salmonicida, injection of crude exotoxins into rainbow trout were shown to reproduce the lesions associated with furunculosis and an accompanying lesion, the dispersion and degranulation of EGCs in the intestinal wall was reported . The present study investigated this phenomenon in relationship to the histamine content of the gut . In fish injected i/p with A . salmonicida exotoxins in a dose causing death in six hours, a coincidental decrease in the histamine content of the gut, appearance of histamine in the blood, and degranulation of the EGCs in the intestinal wall was observed 45 minutes post-injection . The fish developed behaviour patterns similar to that described by other workers for fish undergoing systemic anaphylaxis . Other features were pale gills, defaecation and widespread vasodilatation . The possible role of the EGC as a histaminogenic cell in rainbow trout is discussed. J Clin Microbiol, 1984 Dec, 20(6), 1221 - 2 Value of blood agar for primary plating and clinical implication of simultaneous isolation of Aeromonas hydrophila and Aeromonas caviae from a patient with gastroenteritis; Janda JM et al.; The simultaneous recovery of Aeromonas hydrophila and Aeromonas caviae from the stool of a 49-year-old woman with watery diarrhea was facilitated through the use of a blood agar medium which detected the hemolytic capability of A . hydrophila . In vitro phenotypic tests support the conclusion that only the A . hydrophila isolate was clinically significant. Am J Epidemiol, 1984 Dec, 120(6), 912 - 21 Prophylactic doxycycline for travelers' diarrhea in Thailand . Further supportive evidence of Aeromonas hydrophila as an enteric pathogen; Echeverria P et al.; A randomized double-blind study to determine the efficacy of a three-week course of doxycycline (100 mg daily) in preventing travelers' diarrhea was performed in 1980 among 63 United States Peace Corps volunteers during their first five weeks in Thailand, an area where doxycycline-resistant enterotoxigenic Escherichia coli are known to be common . Eight (24%) of 33 volunteers taking placebo and 3 (10%) of 30 taking doxycycline developed travelers' diarrhea for a calculated protection of 59%, but this was not statistically significant (p = 0.12) . Aeromonas hydrophila was isolated from 8 to 19 volunteers with either travelers' diarrhea or mild diarrhea in the placebo group, but from only 1 of 12 in the doxycycline group (p less than or equal to 0.05) . Furthermore, doxycycline significantly prevented colonization of the gastrointestinal tract with A . hydrophila while it was being taken (p less than or equal to 0.01) . Enterotoxigenic E . coli was isolated from only one volunteer with travelers' diarrhea in the placebo group and from none in the doxycycline group . Doxycycline prophylaxis of travelers' diarrhea in this geographic area, though not shown to be significantly protective, further supports the role of A . hydrophila as an enteric pathogen. J Antimicrob Chemother, 1984 Dec, 14(6), 575 - 9 Resistance of Aeromonas hydrophila to beta-lactam antibiotics; Zemelman R et al.; The activity of some beta-lactam antibiotics upon 20 strains of Aeromonas hydrophila and some properties of their beta-lactamases have been studied . High degree of resistance to benzylpenicillin and lower resistance to ampicillin and cephaloridine was observed . Clavulanic acid showed the highest activity . When clavulanic acid was assayed at subinhibitory concentrations in association with ampicillin . MICs of the latter decreased to two- to eight-fold . All strains produced inducible beta-lactamases with high activity upon ampicillin . A group of cephalosporinase-like enzymes was also found . Some beta-lactamases were inhibited by cloxacillin, and most of them were completely inhibited by 5 mg/l of clavulanic acid . Low impermeability of Aerom . hydrophila cells to beta-lactams was observed. J Hosp Infect, 1984 Dec, 5(4), 425 - 30 Aeromonas hydrophila: an outbreak of hospital infection; Mellersh AR et al.; Aeromonas hydrophila is a Gram-negative water-borne organism widely distributed in the environment . This organism is a recognized cause of diarrhoea and an opportunist pathogen in immunosuppressed patients . An outbreak of hospital-acquired infection which included three cases of pneumonia is reported . The organism was isolated from 19 patients. Eur J Biochem, 1984 Nov 15, 145(1), 107 - 14 Structure of the lipopolysaccharide core isolated from a human strain of Aeromonas hydrophila; Michon F et al.; Lipopolysaccharide was isolated from the cell-walls of a human strain of Aeromonas hydrophila by the aqueous phenol method in 0.58% yield (based on dry weight of bacteria) . The lipopolysaccharide consisted of SR-polysaccharide, core-oligosaccharide and lipid A; there was no O-specific polysaccharide . The core had the composition D-galactose, D-glucose, D-glycero-D-manno-heptose, L-glycero-D-manno-heptose and D-glucosamine in a molar ratio of 1:1:2:4:1 . Glucosamine was linked to an L-glycero-D-manno-heptose residue by a bond which was resistant to hydrolysis . The D-glucosamine-(1----7)-LD-heptose disaccharide was isolated and identified by the mass spectrum of its methylated alditol and the heptose residue not observed under normal hydrolysis conditions was easily determined after deamination of the complete core . Methylation analysis, chemical degradation, periodate and chromium trioxide oxidations and nuclear magnetic resonance (13C and 1H NMR) spectroscopy were used to identify the structure of the core oligosaccharide as: (formula: see text) Can J Biochem Cell Biol, 1984 Nov, 62(11), 1064 - 71 Surface layer virulence A-proteins from Aeromonas salmonicida strains; Kay WW et al.; Superficial surface layer proteins (A-proteins) were present on diverse isolates of Aeromonas salmonicida which differed both physiologically and in pathogenesis . Three of these proteins were purified directly from the surface of whole cells or from outer membrane preparations . These A-proteins were unusually hydrophobic (45-47%) and of similar but not identical molecular mass (49, 50, and 51 kdaltons) . They were nearly identical in amino acid composition and were highly conserved, but not identical with respect to their hydrophobic N-terminal amino acid sequences . These proteins differed, however, with respect to their oligomerization properties, isoelectric forms, and chymotryptic peptide patterns . All three proteins were immunologically closely related and shared surface-exposed immunoreactive peptides with 28 separate isolates. J Pediatr Gastroenterol Nutr, 1984 Nov, 3(5), 808 - 11 Aeromonas hydrophila colitis in a child; Marsik F et al.; A 5-year-old girl presented with chronic bloody diarrhea . Evaluation including sigmoidoscopy, rectal biopsy, and barium enema was consistent with the diagnosis of ulcerative colitis . Culture of the stool grew Aeromonas hydrophila . A . hydrophila colitis may be more common than presently realized. Infect Immun, 1984 Nov, 46(2), 435 - 41 Cloning of enterotoxin gene from Aeromonas hydrophila provides conclusive evidence of production of a cytotonic enterotoxin; Chakraborty T et al.; Culture filtrates of two Aeromonas hydrophila strains which were isolated from patients with diarrhea and assumed to be causative agents of the infections were shown to contain enterotoxic, cytotoxic, and hemolytic activities . Modest heat treatment of the filtrates inactivated the cytotoxic and cytolytic activities, but not the enterotoxic activity . The construction of cosmid gene banks in Escherichia coli of DNA from both A . hydrophila strains demonstrated that the determinants of the three activities are located on three different segments of the A . hydrophila chromosome . Both heated culture filtrates of A . hydrophila and nonheated filtrates of an E . coli clone containing the A . hydrophila enterotoxin gene provoked fluid accumulation in the rabbit ileal loop and suckling mouse models and caused elongation of Chinese hamster ovary cells . Differences in the responses of the models to the A . hydrophila enterotoxin and to the heat-labile and heat-stabile toxins of E . coli indicated that the former is distinct from the latter two types of toxin . These results constitute conclusive evidence for the production by A . hydrophila of a cytotonic enterotoxin that is distinct from the A . hydrophila cytotoxin and hemolysin and known E . coli enterotoxins. Appl Environ Microbiol, 1984 Oct, 48(4), 865 - 7 Isolation of enterotoxigenic, hemolytic, and antibiotic-resistant Aeromonas hydrophila strains from infected fish in Bangladesh; Rahim Z et al.; Strains of Aeromonas hydrophila isolated from skin infections of common freshwater fish in Bangladesh were tested for enterotoxin production, hemolysin production, and any correlation between these two activities . We also tested the resistance patterns of A . hydrophila to different drugs, especially in relation to ampicillin . The A . hydrophila strains produced an enterotoxin that was related to their beta-hemolytic activities . Production of beta-hemolysin may thus be an indicator of enterotoxicity . As 50% of the strains of A . hydrophila were found to be susceptible to 12.5 micrograms of ampicillin per ml, media containing this antibiotic may not be suitable for their isolation. Infect Immun, 1984 Oct, 46(1), 122 - 7 Purification and some properties of Aeromonas hydrophila hemolysin; Asao T et al.; A hemolysin produced by a strain of Aeromonas hydrophila isolated from a patient with diarrhea was purified by acid precipitation and quarternary aminoethyl-Sephadex chromatography . The molecular weight of the hemolysin was estimated at 50,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and at 48,000 by Sephadex G-100 gel filtration . In polyacrylamide gel electrophoresis at pH 4.0 and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the hemolysin migrated as a single band, whereas electrophoresis at pH 9.4 and thin-layer isoelectric focusing demonstrated multiple bands . The results may indicate charge isomers of the hemolysin . The purified hemolysin had a hemolytic activity of 134 hemolytic units per microgram of protein on rabbit erythrocytes . It caused fluid accumulation in infant mouse intestines and rabbit ligated ileal loops . Purified hemolysin also elicited cytotoxicity to Vero cells and lethal toxicity to mice . All these biological activities were lost on heating for 5 min at 56 degrees C . These findings support the notion that A . hydrophila hemolysin is a cytotoxic enterotoxin. Arch Intern Med, 1984 Oct, 144(10), 2078 - 9 Pyogenic meningitis manifesting during therapy for Aeromonas hydrophila sepsis; Ellison RT 3rd et al.; Pyogenic meningitis became apparent on the third day of ampicillin and gentamicin therapy for Aeromonas hydrophila sepsis in a patient with severe alcoholic hepatitis . The patient responded clinically to therapy with intravenous cefotaxime sodium and gentamicin sulfate . Antibiotic therapy that provides adequate CSF concentrations should be considered in the treatment of patients with Aeromonas sepsis. J Trauma, 1984 Sep, 24(9), 803 - 10 Thromboxane interaction with cardiopulmonary dysfunction in graded bacterial sepsis; Slotman GJ et al.; The relationship between plasma levels of thromboxane A2, radioimmunoassayed as thromboxane B2 (TxB), and cardiopulmonary dysfunction in graded bacterial sepsis was investigated . Five adult female pigs under anesthesia were intubated and allowed to breathe room air spontaneously . Femoral arterial, venous, and pulmonary artery catheters were inserted . After a 60-minute control period Aeromonas hydrophila (1.0 X 10(9)/ml) was infused intravenously at 0.2 ml/kg/hr, gradually increasing to 4.0 ml/kg/hr over 4 hours . Arterial and mixed venous blood gases, hemodynamic measurements, and TxB plasma concentrations were obtained during the control period, at 10, 20, 30, 45, and 60 minutes and at 30-minute intervals thereafter . Cardiac index increased significantly from control at 20 minutes, remained above control levels for 1 hour, and then declined to significantly low values at 150 minutes . TxB was increased from control at 20 minutes, rising to four times control at 120 minutes . Mean arterial pressure, pulmonary capillary wedge pressure, left ventricular stroke work, paO2, and pvO2 decreased significantly during the experiment . Pulmonary artery pressure and pulmonary vascular resistance increased significantly . Changes in TxB were significantly cross-correlated with changes in cardiac index, pulmonary vascular resistance, stroke volume, left ventricular stroke work, and paO2 . TxB elevations led the cross-correlated variables by 0 to 60 minutes . Pulmonary vascular resistance cross-correlated with mean arterial pressure and cardiac index . TxB is increased early in graded bacterial sepsis . Changes in TxB appear to precede impaired cardiopulmonary function . The data suggest that TxB is involved in the detrimental hemodynamic effects of early septicemia. Can J Microbiol, 1984 Sep, 30(9), 1190 - 2 {Demonstration of a proteolytic activity on intracellular origin in Aeromonas hydrophila LP 50}; Denis F et al.; Aeromonas hydrophila LP 50, isolated from packaged pasteurized milk, was grown in glucose-polypeptone medium at 30 degrees C . The proteolytic activity of A . hydrophila LP 50, optimum at the stationary phase of growth, is attributed to extracellular or membrane protease; no intracellular proteolytic activity was shown. Appl Environ Microbiol, 1984 Aug, 48(2), 456 - 8 Effects of short-term cold storage on recovery of proteases from extracellular products of Aeromonas hydrophila; Amborski RL et al.; Three protease-containing fractions were recovered by gel filtration from concentrated crude extracellular products produced by Aeromonas hydrophila grown in a defined medium . The recovery of a heat-stable protease was differentially prevented when the crude preparation was stored for 48 h at -20 degrees C but was unaffected by storage of the crude preparation at either 4 or -70 degrees C . Once fractionated, the heat-stable protease appeared to be unaffected by subsequent storage at 4, -20, or -70 degrees C. Appl Environ Microbiol, 1984 Aug, 48(2), 361 - 6 Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates; Burke V et al.; The occurrence of Aeromonas spp . in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year . Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp . in numbers comparable to those in raw surface water, although this water was free of Escherichia coli . Coliforms and E . coli were found in raw surface waters, and Aeromonas spp . were found in raw water from surface and underground sources . Chemical treatment, followed by chlorination at service reservoirs, resulted in water free of E . coli and a decrease in the number of Aeromonas spp . Aeromonas spp . were found in the greatest numbers in summer . Multiple regression analysis showed that growth of Aeromonas spp . in chlorinated water was related to water temperature, residual chlorine, and interaction between these variables . The incidence of Aeromonas-associated gastroenteritis, determined from isolates referred to us for enterotoxin testing, paralleled the pattern of isolation of Aeromonas spp . in water within the distribution systems . We suggest that the presence of Aeromonas spp . in drinking water needs public health appraisal and that further work should be undertaken to permit reevaluation of standards for the quality of drinking water. Avian Dis, 1984 Jul-Sep, 28(3), 804 - 7 The occurrence of Aeromonas hydrophila in avian diagnostic submissions; Shane SM et al.; Twenty isolations of Aeromonas hydrophila were made from 15 species of free-living, commercial, and companion birds submitted for routine diagnostic postmortem examination . Seventy percent of the isolations were made from November through March during the 25-month survey period. Can J Microbiol, 1984 Jul, 30(7), 900 - 4 Difference in the extracellular products of two strains of Aeromonas hydrophila virulent and weakly virulent for fish; Lallier R et al.; In this study we first compared the toxigenic profile of Aeromonas hydrophila strains virulent and weakly virulent for rainbow trout . The separation of the toxic factor for fish is also described . Both strains produced hemolytic, enterotoxic, and dermonecrotic activities; the weakly virulent strain produced 20 times more hemolysin . Only the cell-free supernatant of the virulent strain produced a toxic factor for fish . After passage on Sephacryl S-200, the toxic factor for fish was separated from the hemolysin . This toxic factor is heat labile. Jpn J Med Sci Biol, 1984 Jun, 37(3), 141 - 4 Production of cholera-like enterotoxin by Aeromonas hydrophila; Shimada T et al.; A total of 249 strains of mesophilic Aeromonas including 179 A . hydrophila and 70 A . caviae were tested for production of cholera-like enterotoxin by reversed passive latex agglutination (RPLA) assay . A cholera-like enterotoxin neutralized with cholera antitoxin was demonstrated in the culture filtrates from eight (4.5%) of the 179 A . hydrophila strains, while none of A . caviae strains revealed the enterotoxin production in the test . Production of the cholera-like enterotoxin in the eight strains of A . hydrophila was also confirmed by enzyme-linked immunosorbent assay (ELISA). Onderstepoort J Vet Res, 1984 Jun, 51(2), 91 - 4 Furunculosis in rainbow trout (Salmo gairdneri) raised in sea water; Boomker J et al.; Ulcerative skin lesions were encountered in rainbow trout raised in sea water by a commercial concern in the Western Cape, South Africa . Grossly, the lesions resembled furunculosis but, histopathologically, they differed from typical furunculosis in that bacterial colonies were rarely found in the organs, and also the kidneys and spleens were minimally involved . The causative organism was identified as an achromogenic Aeromonas salmonicida that shared characteristics with all 3 subspecies, salmonicida, masoucida and achromogenes . This is the first report of an outbreak of this disease in South Africa. J Hosp Infect, 1984 Jun, 5(2), 205 - 9 The use of a biotyping system to investigate an unusual clustering bacteraemias caused by Aeromonas species; Cookson BD et al.; Aeromonas spp . were isolated from blood cultures taken from four clinically bacteraemic patients over an 18 day period on four separate wards . A common source was suspected and extensive environmental sampling revealed two more ward isolates of Aeromonas spp . A biotyping system was employed which distinguished the strains from each other and indicated that a common source was unlikely . This coincidental clustering occurred in the autumn, a period when isolates from water and faeces are normally at a peak . All patients were debilitated and it is postulated that their own gastrointestinal tracts acted as the most likely route for their bacteraemias. Presse Med, 1984 May 5, 13(19), 1203 - 5 {Aeromonas hydrophila septicemia . Epidemiologic aspects . 15 cases}; Picard B et al.; Fifteen cases of Aeromonas hydrophila septicaemia, characterized by their frequent pulmonary lesions and the severity of their course, are reported . The delay observed between admission to hospital and first symptoms, together with the presence of anatomical lesions or physiological disturbances suggesting bacterial invasion by the intestinal route, have led the authors to postulate a nosocomial digestive contamination, probably from water, as suggested by the particular ecology of this micro-organism . This hypothesis was supported by the finding of Aeromonas hydrophila in large numbers at the different points of the hospital water distribution system where samples were taken. Eur J Immunol, 1984 May, 14(5), 442 - 7 Immunodominant protein epitopes . I . Induction of suppression to hen egg white lysozyme is obliterated by removal of the first three N-terminal amino acids; Wicker LS et al.; The lack of response to hen egg white lysozyme (HEL) by C57BL (H-2b) mice has been demonstrated previously to be related to the induction of suppressor T (Ts) cells which recognize the amino terminal region of HEL . In this report, the nature of the protein determinant required for Ts cell induction is more precisely detailed using des-1,2,3-HEL (AP-HEL) prepared with an aminopeptidase purified from Aeromonas proteolytica . Remarkably, the removal of just these three amino acids obliterates the ability of HEL to induce Ts cells specific for HEL . Additionally, in contrast to HEL, AP-HEL is able to prime for an in vitro T cell proliferative response to either AP-HEL or HEL . Thus, removal of a very limited region of a protein antigen can drastically alter its immunogenic properties. J Bacteriol, 1984 Apr, 158(1), 16 - 22 Structural and immunochemical homogeneity of Aeromonas salmonicida lipopolysaccharide; Chart H et al.; Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the lipopolysaccharides of typical and atypical strains of the fish pathogen Aeromonas salmonicida . 32P intrinsically radiolabeled lipopolysaccharide in sarcosinate-extracted outer membrane preparations, lipopolysaccharide stained by silver in proteinase K-digested outer membrane preparations and whole cell lysates, as well as purified lipopolysaccharide, displayed O-polysaccharide chains which were unusually homogeneous with respect to chain length . Chemical analysis further revealed that the sugar composition of the smooth lipopolysaccharide purified from three typical strains was very similar . Immunoblotting and immunofluorescent staining with both polyclonal and monoclonal antibody showed that the O-polysaccharide chains were strongly immunogenic and were antigenically cross-reactive on typical and atypical strains from diverse origins . Immunofluorescence analysis and phage binding studies demonstrated that a number of these O-polysaccharide chains traversed the surface protein array of virulent strains of A . salmonicida and were exposed on the cell surface. Ann Microbiol (Paris), 1984 Mar-Apr, 135A(2), 219 - 27 {Partial purification of the extracellular proteolytic system of Aeromonas hydrophila LP50: comparative chromatographic and electrophoretic study}; Denis F et al.; A complex extracellular proteolytic system was produced by Aeromonas hydrophila LP50 on glucose- polypeptone medium . Partial purification of this system was accomplished by ammonium sulphate precipitation, acetone precipitation, gel filtration on Sephacryl- S200 and chromatography on DEAE-Sephacel . Every stage was controlled by electrophoresis . This proteolytic system was constituted of three aminopeptidase and two endopeptidase components. Sem Hop, 1984 Feb 16, 60(8), 577 - 9 {Severe Aeromonas hydrophila infections . Apropos of 2 cases}; Guerin JM et al.; The authors describe two personal cases of severe Aeromonas hydrophila infection . They review the symptomatology and treatment of such cases and insist on the unusual features in their patients. J Clin Microbiol, 1984 Feb, 19(2), 175 - 80 Enterotoxin production in relation to taxonomic grouping and source of isolation of Aeromonas species; Turnbull PC et al.; A total of 19 of 20 (95%) strains of Aeromonas hydrophila biovar hydrophila and 16 of 17 (94%) strains of Aeromonas sobria isolated from a variety of clinical and environmental sources were found to be enterotoxin positive . Only 2 of 18 (11%) A . hydrophila biovar anaerogenes and 2 of 13 (15%) unidentified Aeromonas strains from a similar variety of sources produced enterotoxin . No association was apparent between the source of isolation, in particular diarrheal stools, and enterotoxigenicity; 41% of the isolates from diarrheal stools were enterotoxin negative . A strong correlation was noted between ability to produce enterotoxin and positive results in six characters: lysine decarboxylase and Voges-Proskauer reactions, production of gas from glucose, gluconate oxidation, xanthine hydrolysis, and hemolysis of human erythrocytes . In the majority of cases (35 of 39 strains), enterotoxigenicity was detected using cell-free filtrates of brain heart infusion broth cultures grown at 36 degrees C for 15; however, the other four positive isolates were detected after growth in the same broth at 30 degrees C or in Casamino Acids-yeast extract broth at 30 or 37 degrees C . It is recommended that for enterotoxin tests, strains should be grown in both media at both temperatures . The infant mouse test was found to be a simple and reliable method for detection of the enterotoxin . The toxin proved to be heat labile and not neutralized by cholera antitoxin. J Clin Microbiol, 1984 Jan, 19(1), 44 - 7 Biotyping of Aeromonas isolates as a correlate to delineating a species-associated disease spectrum; Janda JM et al.; A group of 147 Aeromonas isolates from diverse clinical and environmental sources was subjected to the biotyping scheme of Popoff and Veron . Of the 147 isolates biotyped, 137 (93%) could be identified, with Aeromonas hydrophila predominating (48%) and equal percentages (25 to 27%) of the other two species (Aeromonas sobria and Aeromonas caviae) . A number of additional biochemical properties were found to be significantly associated with one or more of these three species . These included lysine decarboxylase activity, hemolysis of sheep erythrocytes, lecithinase production, staphylolytic activity, arbutin hydrolysis, and acid production from utilization of various carbohydrates . By incorporating these phenotypic properties into an extended biotyping system, 98% of the isolates were identified . Selective distribution of individual species with respect to certain body sites was noted. J Clin Microbiol, 1984 Jan, 19(1), 39 - 43 Hemagglutination patterns of Aeromonas spp . in relation to biotype and source; Burke V et al.; Aeromonas spp . show patterns of hemagglutination with human group O cells in the presence of fucose, galactose, and mannose . These patterns are related to biotype as well as to the source of isolates . There was good correlation between hemagglutination pattern and the presence of diarrhea among strains isolated in Western Australia, which was the only source with adequate data for classification of children with an without diarrhea . Most of the environmental and other nonfecal isolates produced patterns different from those in strains associated with diarrhea . These results suggest that hemagglutinins should be considered with enterotoxins as virulence factors in Aeromonas spp. Bull Soc Pathol Exot Filiales, 1984 Jan-Feb, 77(1), 17 - 27 {Aeromonas hydrophila in Ivory Coast Epidemiologic and ecologic aspects and its enteropathogenic role}; Dosso M et al.; A research based on the analysis of 479 coprocultures , allow the isolation of 22 strains of Aeromonas hydrophila . The epidemiological aspects, the contamination processes through water, food.. . and the enteropathogenic role of these Aeromonas are discussed . These bacteria seen responsible of digestive disturbances from simple gastric discomfort (nausea, light abdominal pain...) to the actual choleriform syndrome . The isolation of 7 strains from the environment (water from lagune , wells; lagune crabs) allow to suspect the role played by the seasonal variations of the lagune salinity in the development of the germ; this allow to drawn the following conclusions: the reduction of the rate of water salinity promotes the multiplication of Aeromonas and increase the risk of human contamination. Dev Comp Immunol, 1984 Summer, 8(3), 569 - 78 Induction of nonspecific immunosuppression in a primitive teleost, rainbow trout (Salmo gairdneri); Sakai DK; Induction of immunological non-reactivity to goldfish red blood cells (GFRBC), sheep red blood cells (SRBC) and to formalin-killed Aeromonas salmonicida cells was obtained in yearling rainbow trout raised under laboratory aquarium conditions (at 10 degrees C) . Haemolysin and agglutinin titres were measured 1 to 4 weeks after immunization . While trout immunized with low and high doses of antigen by intramuscular (im) and intraperitoneal (ip) injections produced high antibody titres, administration of high doses of antigen by intravascular (iv) injection induced a state of tolerance which was antigen nonspecific . This lack of response persisted for at least 3 weeks . The phagocytic activity of peritoneal exudate cells from immunosuppressed fish was reduced . The numbers of plaque-forming cells amongst peripheral lymphocytes collected from trout receiving a high dose of GFRBC iv was markedly low when compared with those from trout receiving a similar dose ip . These findings are of interest since they demonstrate that the induction of antigen-nonspecific tolerance by iv administration of high doses of antigen in rainbow trout may be due to the generation of nonspecific suppressor cells. J Gen Microbiol, 1983 Dec, 129 ( Pt 12), 3661 - 9 Enhancement of bacterial adhesion by shear forces: characterization of the haemagglutination induced by Aeromonas salmonicida strain 438; Brooks DE et al.; Application of a viscometric assay to the haemagglutination induced by Aeromonas salmonicida strain 438 showed that shear forces can enhance the strength of bacterial adhesion . The D-mannose/L-fucose-sensitive reaction proceeded in two phases, an initial phase in which the degree of aggregation remained constant during shearing and a second stage, induced by shear, in which agglutination was enhanced as shear was maintained . The results strongly paralleled those found in studies of concanavalin A-induced haemagglutination, providing good evidence that adhesion in this species took place via lectin-like molecules . Methyl-alpha-D-mannoside, which strongly inhibits haemagglutination in this system, would not fully reverse the shear-dependent reaction . EGTA inhibited and reversed both phases, however . The effects of bacterial concentration, temperature, time of growth, pH, and a spectrum of monosaccharide inhibitors were also studied . The results demonstrated that the shear-dependent reaction has a number of features which distinguish it from the initial stage of haemagglutination, implying differences in the underlying biochemical mechanisms involved. J Biol Chem, 1983 Nov 25, 258(22), 13517 - 21 Stereospecificity of amino acid hydroxamate inhibition of aminopeptidases; Wilkes SH et al.; Hydroxamates of amino acids and aliphatic acids are effective inhibitors of Aeromonas proteolytica amino-peptidase (EC 3.4.11.10) and of both the cytosolic (EC 3.4.11.1) and microsomal (EC 3.4.11.2) aminopeptidases of swine kidney . Cytosolic leucine aminopeptidase and the Aeromonas enzyme were inhibited to a greater extent by D isomers than by the L enantiomorphs, manganese-activated kidney cytosolic leucine aminopeptidase being inhibited 10 times more effectively by D-leucine and D-valine hydroxamic acids than by the L isomers . The D isomers of these two compounds inhibited Aeromonas aminopeptidase to an even greater extent with Ki values of 2 X 10(-9) and 5 X 10(-9), respectively, whereas the corresponding L isomers were bound 150 times less tightly . With the Aeromonas enzyme, a comparison of inhibition by racemic mixtures with that of the corresponding L isomers indicated that in all cases the contribution of the D isomer was predominant . Isocaproic hydroxamic acid inhibited this enzyme equally well as L-leucine hydroxamic acid, indicating that the amino group orientation in the D isomer contributes to the binding efficacy . Swine kidney microsomal aminopeptidase was also inhibited by D isomers of leucine and valine hydroxamic acids but in contrast to the other two enzymes, the inhibition was 10-fold less than that observed for the corresponding L isomers . Cytosolic leucine aminopeptidase with either 6 g atoms of zinc per mol or 12 g atoms of zinc per mol was inhibited only slightly by any of the hydroxamic acid compounds; evidently enzyme-bound manganese (or magnesium) is specific for hydroxamate binding to this aminopeptidase. J Bacteriol, 1983 Nov, 156(2), 758 - 64 Acquisition of iron by Aeromonas salmonicida; Chart H et al.; The ability of six typical and three atypical strains of Aeromonas salmonicida to sequester Fe3+ from the high-affinity iron chelators ethylenediaminedihydroxy-phenylacetic acid, lactoferrin, and transferrin was determined . Typical strains were readily able to sequester Fe3+ and used two different mechanisms . One mechanism was inducible and appeared to involve production of a low-molecular-weight soluble siderophore(s) . Iron uptake by this mechanism was strongly inhibited by ferricyanide . One virulent strain displayed a second mechanism which was constitutive and required cell contact with Fe3+-lactoferrin or -transferrin . This strain did not produce a soluble siderophore(s) but could utilize the siderophore(s) produced by the other strain . Fe3+ uptake by this stripping mechanism was strongly inhibited by dinitrophenol . Atypical strains displayed a markedly reduced ability to sequester iron from high-affinity chelators, although one of them was able to utilize the siderophores produced by the typical strain . In all strains examined, Fe3+ limitation resulted in the increased synthesis of several high-molecular-weight outer membrane proteins. Arch Intern Med, 1983 Nov, 143(11), 2073 - 4 Posttraumatic Aeromonas hydrophila osteomyelitis; Karam GH et al.; Aeromonas hydrophila is a gram-negative organism that is the causative agent in several clinical infections . Although it has been reported to cause osteomyelitis in immunocompromised patients, it has not been reported to cause this in the normal host . We describe two patients in whom acute osteomyelitis developed following trauma in freshwater lakes . Cultures yielded A hydrophila, and both patients responded to a two-week course of parenteral antibiotics followed by oral tetracycline hydrochloride in the outpatient setting . Since A hydrophila is a common inhabitant of freshwater lakes, it should be suspected in infections occurring in this epidemiologic setting. Can J Microbiol, 1983 Oct, 29(10), 1458 - 61 A lipopolysaccharide-specific bacteriophage for Aeromonas salmonicida; Ishiguro EE et al.; Cell wall lipopolysaccharide (LPS) was identified as the receptor for the Aeromonas salmonicida bacteriophage strain 55R-1 . Mutants of A . salmonicida resistant to phage 55R-1 were unable to adsorb phage 55R-1 and were shown to be defective in LPS structure . Purified A . salmonicida LPS inactivated phage 55R-1, but the O-polysaccharide and the core oligosaccharide portions of the LPS were ineffective . These results suggest that lipid A was required for receptor activity . Antibodies directed against LPS also inhibited phage adsorption. Arch Intern Med, 1983 Oct, 143(10), 2005 - 7 Aeromonas hydrophila myonecrosis and gas gangrene in a nonimmunocompromised host; Heckerling PS et al.; Aeromonas hydrophila myonecrosis with gas gangrene and bacteremia developed in an elderly patient after minor trauma from a fishbone . Despite aggressive medical and surgical therapy, she experienced a rapidly fatal outcome . Literature on Aeromonas muscle infection is reviewed and implications for therapy are discussed. Diagn Microbiol Infect Dis, 1983 Sep, 1(3), 221 - 8 Aeromonas species in clinical microbiology: significance, epidemiology, and speciation; Janda JM et al.; Over a one-year period, 32 strains (31 clinical, 1 environmental) of Aeromonas sp . were recovered . Chief sources of isolation were the gastrointestinal tract (48%), wounds (19%), and blood (13%) . Gastrointestinal isolates were most often recovered from young (less than 5 yrs) children with diarrhea; wound or blood isolates were recovered more often from an older (avg . 56 yrs) population with one of several underlying disorders . Regardless of body site of isolation, most strains of Aeromonas appeared to be community acquired and not nosocomially transmitted . Over 70% of all isolates recovered during this year period were isolated during summer or fall months, suggesting a seasonal distribution of this microorganism . Speciation of Aeromonas isolates revealed A . hydrophila to be the predominant species isolated from clinical specimens, although significant percentages of other Aeromonas sp . were also recovered from clinical material. Southeast Asian J Trop Med Public Health, 1983 Sep, 14(3), 330 - 5 Distribution of IMVC biogroups of Aeromonas hydrophila and Aeromonas sobria isolated from human, fish and water; Sukroongreung S et al.; Aeromonas sobria and A.hydrophila were isolated from infected fish in ratio of 3.5:1 during the outbreak of fish infections from December 1982 to February 1983, while isolates from human diarrheic stool was 1 :2 . On the basis of IMVC reactions 138 isolates of motile aeromonads could be divided into 11 biogroups, with biogroup 4 showing statistically significant association with infections . Nine biogroups of aeromonads which were isolated from infected fish reflected that the outbreak was not caused by a single type of bacteria . There may have been some common factors which acted as predisposing causes . The possibility of zoonosis spreading of this epidemic infection of fish was low, because the majority of the infective agents in man and fish were different. Experientia, 1983 Aug 15, 39(8), 924 - 6 Investigation of Aeromonas isolated from water; a serological study using Ouchterlony and immunoelectrophoresis techniques; Peduzzi R et al.; We have shown that immunoelectrophoresis and the Ouchterlony double diffusion technique are valuable assays for the identification of Aeromonas species . Serological correlations have been found between the antigenic extracts originated from a collection reference strains of Aeromonas hydrophila subsp . hydrophila and those originated from wild type water isolated. Biochem Biophys Res Commun, 1983 Jul 29, 114(2), 646 - 52 One hundred fold increased activity of Aeromonas aminopeptidase by sequential substitutions with Ni(II) or Cu(II) followed by zinc; Prescott JM et al.; Full substitution of Cu(II) or Ni(II) for the two g-atom zinc in Aeromonas aminopeptidase hyperactivates the enzyme 6.5 and 25 fold respectively . Even greater enhancements of activity can be achieved with mixed metal substitutions . Thus, apoenzyme reactivated by first adding one g-atom zinc followed by one g-atom of either Cu(II) or Ni(II) is 15 and 22 times more active than the native enzyme . Reversing the order, i.e . by first adding either one g-atom Cu(II) or Ni(II) followed by one g-atom zinc, activates the enzyme nearly 100 fold . The order of metal addition is critical and suggests the existence of two non-identical metal sites, each with a different function. Biochemistry, 1983 Jun 7, 22(12), 2934 - 9 Purification and characterization of the cell surface virulent A protein from Aeromonas salmonicida; Phipps BM et al.; The predominant cell surface protein (A protein) of Aeromonas salmonicida has been purified in high yield from outer membranes by using a combination of detergent and chaotropic extraction methods as well as exclusion and ion-exchange chromatography . The A protein was primarily monomeric, Mr 50 000, but readily formed oligomers at high protein or low salt concentrations . Several isoelectric forms were distinguishable with purified protein as well as in situ on the cell surface . Neither phosphate nor carbohydrate was detectable . The A protein was hydrophobic in composition and the N-terminal sequence highly hydrophobic . From CD spectra the A protein exhibited 14% alpha helix and 19-28% beta structure and could also be readily crystallized . By fluorescent antibody staining the A protein was shown to cover the entire cell surface but was absent from A protein deficient mutants . This protein appears to have no apparent enzymatic activity but rather constitutes a macromolecular refractile protein barrier essential for virulence. J Clin Microbiol, 1983 Jun, 17(6), 1175 - 6 Minimal inhibitory concentrations of antimicrobial agents against Aeromonas hydrophila determined with the Autobac MTS; Overman TL et al.; Minimal inhibitory concentrations of seven antimicrobial agents for 22 strains of Aeromonas hydrophila were determined with the Autobac MTS procedure . The ranges of the minimal inhibitory concentrations were found to be similar to those obtained by a microdilution procedure . Depending upon the interpretive criteria used, there were discrepancies with carbenicillin, cephalothin, kanamycin, and tetracycline . It is recommended that the beta-lactam antibiotics ampicillin, carbenicillin, and cephalothin not be tested because of their lack of clinical usefulness, thus completely eliminating all of the significant discrepancies and reducing expendable costs by 50%. Eur J Biochem, 1983 Apr 5, 131(3), 633 - 8 Structural studies on the O-antigen of Aeromonas salmonicida; Shaw DH et al.; Lipopolysaccharide from a strain of Aeromonas salmonicida salmonicida was isolated from cells by the aqueous phenol method in 2.3% yield (based on dry weight of bacteria) . Hydrolysis of the lipopolysaccharide in 1% acetic acid afforded O-polysaccharide (19% by weight), core-oligosaccharide (12.2%) and lipid A (44.6%) . Analysis indicated that 3-deoxy-D-manno-2-octulosonic acid was absent from the lipopolysaccharide and that no low-molecular-weight compounds were released by the mild hydrolysis . The O-polysaccharide had the monosaccharide composition of rhamnose, glucose and N-acetylmannosamine in molar ratio of 1.0:1.58:0.83 . 75% of the N-acetylmannosamine residues were substituted at position 4 by O-acetyl groups . Hydrolysis of the methylated polysaccharide proved to be both difficult and dependent on the method of hydrolysis chosen, in all cases a partially methylated disaccharide of rhamnose and N-acetylmannosamine was identified in the hydrolysate . Methylation analysis, periodate oxidation and proton magnetic resonance analysis were used to confirm the structure of the repeating unit as: (formula; see text). J Clin Microbiol, 1983 Apr, 17(4), 588 - 91 Phenotypic markers associated with gastrointestinal Aeromonas hydrophila isolates from symptomatic children; Janda JM et al.; Aeromonas hydrophila gastroenteritis was detected in 12 pediatric patients during a 5-month period . Chief complaints included bloody diarrhea, fever, vomiting, and abdominal pain . Severe symptoms in two patients necessitated hospitalization and supportive care . Phenotypic characteristics associated with enterotoxigenicity of A . hydrophila strains demonstrated that all 12 isolates were cytotoxic to HeLa cells and most were lysine decarboxylase positive (75%) . A correlation existed between the presence of the five virulence-associated markers of two isolates of A . hydrophila and the severity of disease . Although the length and symptoms of gastroenteritis varied among all 12 patients, most had self-limiting diarrhea . The frequent occurrence of A . hydrophila gastroenteritis in pediatric patients warrants a greater appreciation of this agent as a significant cause of diarrhea, especially in summer. J Bacteriol, 1983 Apr, 154(1), 413 - 8 Intracellular accumulation of extracellular proteins by pleiotropic export mutants of Aeromonas hydrophila; Howard SP et al.; Pleiotropic export mutants of Aeromonas hydrophila were obtained which are unable to release protease, hemolysin, and glycerophospholipid:cholesterol acyltransferase . The synthesis of the proteins was not impaired; they were accumulated in active forms inside the mutant cells . The hemolysin could be isolated from cell contents by immunoprecipitation in a form with the same apparent molecular weight as the wild-type extracellular product, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Because both the protease and the hemolysin could be released from the mutant cells by osmotic shock, it was concluded that they were accumulated in the periplasmic space . Some mutants were missing two major outer membrane proteins, both of which reappeared in revertants with the wild-type excretory phenotype . Another mutant class had a normal outer membrane protein profile . That two different mutant classes could be obtained indicates that at least two gene products may be needed for export after protein translocation through the inner membrane . The accumulation of proteins which can be released by osmotic shock suggests that the periplasm may be part of the normal route for protein export. Br J Plast Surg, 1983 Apr, 36(2), 240 - 4 The medicinal leech and its use in plastic surgery: a possible cause for infection; Whitlock MR et al.; Recent interest in the use of the medicinal leech (Hirudo medicinalis) in microsurgical practice prompted us to undertake a bacteriological study . Aeromonas hydrophila was consistently cultured from 9 leeches that we examined . This organism is pathogenic to man and we consider that there is a significant risk of infection, particularly in those procedures where the vascularity of the tissues is compromised . There are several pharmacological preparations which have similar properties to the secretion of the medicinal leech and we submit that these non-infective preparations may be worthy of investigation. J Appl Bacteriol, 1983 Apr, 54(2), 289 - 94 Purification and characterization of a new proteolytic enzyme produced by Aeromonas salmonicida; Mellergaard S; A proteolytic enzyme produced by the fish pathogen Aeromonas salmonicida was isolated and purified . It showed the following characteristics: temperature optimum at 48 degrees C, pH optimum at pH 9 and a molecular weight of 87500 . The enzyme was inhibited by phenylmethanesulphonylfluoride (PMSF) indicating it to be a serine protease. Biochem Biophys Res Commun, 1983 Mar 29, 111(3), 946 - 51 ES complexes of Aeromonas aminopeptidase: direct observation by stopped-flow fluorescence; Auld DS et al.; Intermediates of Aeromonas aminopeptidase are monitored through fluorescence generated by radiationless energy transfer (RET) between enzyme tryptophans and the dansyl group of the bound substrate . Upon binding of the substrate enzyme tryptophan fluorescence is quenched and substrate dansyl fluorescence enhanced . These processes are reversed upon hydrolysis of the Leu-Ala bond and release of Ala-DED from the enzyme . Stopped-flow RET kinetic analysis yields values of kcat = 36 sec-1 and Km = 3.7 microM at pH 7.5 and 20 degrees C . These values represent the highest kcat/Km ratio, 1 X 10(7) M-1 sec-1, of any substrate for Aeromonas aminopeptidase . The excellent binding properties of the peptide permit direct visualization of ES complexes even at enzyme concentrations of 10(-7) M. J Clin Microbiol, 1983 Mar, 17(3), 422 - 7 Aeromonas hydrophila typing scheme based on patterns of agglutination with erythrocytes and yeast cells; Adams D et al.; An agglutination typing scheme has been developed for strains of Aeromonas hydrophila . Primary agglutination typing is based on testing agar-grown A . hydrophila cells with human, horse, rat, and guinea pig erythrocytes and Saccharomyces cerevisiae cells . Further subdivision of primary groups is based firstly on whether yeast cell agglutination is inhibited by a D-mannose polymer, yeast mannan, and secondly on patterns of inhibition of hemagglutination by yeast mannan and the monomeric sugars L-fucose, D-galactose, and D-mannose . A total of 320 isolates were tested, and these were divisible into 39 distinct types on the basis of this scheme . Application of this typing scheme in the future to isolates of A . hydrophila known to be associated with human infection may enable correlations to be made between particular agglutination types and human pathogenicity. Appl Environ Microbiol, 1983 Mar, 45(3), 1132 - 5 Effects of cultural conditions on protease production by Aeromonas hydrophila; O'Reilly T et al.; Production of extracellular proteolytic activity by Aeromonas hydrophila was influenced by temperature, pH, and aeration . Conditions which produced maximal growth also resulted in maximal protease production . Enzyme production appeared to be modulated by an inducer catabolite repression system whereby NH4+ and glucose repressed enzyme production and complex nitrogen and nonglucose, carbon energy sources promoted it . Under nutritional stress, protease production was high, despite poor growth. Vet Microbiol, 1983 Feb, 8(1), 17 - 34 Enterotoxigenicity, hemagglutination and cell-surface hydrophobicity in Aeromonas hydrophila, A . sobria and A . salmonicida; Jiwa SF; Thirty-one Aeromonas hydrophila, 13 A . sobria and two A . salmonicida strains of diverse sources were tested for enterotoxigenicity, hemagglutination and cell surface hydrophobicity . Although 93% of the culture supernatant fluids of the Aeromonas strains exhibited cytotoxic effects on Y1 adrenal and Chinese hamster ovary (CHO) cells, typical rounding of Y1 adrenal cells was reproducibly observed before cytotoxicity for 80% of the isolates within 1 h of exposure . Twenty-eight strains were positive for delayed permeability factor (DPF) activity in rabbit skin . Culture filtrates of 16 of 20 strains that were positive both in the Y1 adrenal cell test and for DPF activity elicited fluid accumulation in rabbit ileal loops . The DPF and ileal loop activities were neutralizable by cholera antitoxin . All, except two strains each of A . sobria and A . hydrophila, produced a heat-stable, rapid permeability factor (RPF) detected in rabbit skin . Heat-treated culture supernatant fluids of two A . hydrophila and one A . sobria isolate gave positive responses in the infant mouse assay . Nine other strains gave borderline reactions . When A . hydrophila and A . sobria isolates were grown in broth, approximately 90% agglutinated bovine, chicken, human group A and guinea-pig erythrocytes in the presence of mannose at 4 degrees C and/or 20 degrees C . The two A . salmonicida isolates produced mannose resistant hemagglutination (MRHA) of these four blood types . Hydrophobic interaction chromatography indicated adhesive potential in 61% A . hydrophila and 100% A . sobria strains expressing weak to strong hydrophobic cell surface properties . The results of these investigations strongly imply that the Aeromonas strains produce a cytotonic enterotoxin immunologically related to cholera toxin . Adhesive characteristics were commonly found in both clinical and routine isolates. Med J Aust, 1983 Jan 8, 1(1), 25 - 6 Enterotoxigenic Aeromonas hydrophila and diarrhoea in adults; Goodwin CS et al.; Aeromonas hydrophila was isolated from the faeces of 32 patients during a nine month period in three hospitals in Western Australia . All 32 isolates produced enterotoxin which was detected by the suckling-mouse test, and all patients except one had diarrhoea . Treatment should be considered in patients with chronic diarrhoea and in those with malignant disease or with hepatobiliary disease who are at risk of developing aeromonas septicaemia. J Clin Microbiol, 1983 Jan, 17(1), 16 - 21 Evaluation of differential and selective media for isolation of Aeromonas and Plesiomonas spp . from human feces; von Graevenitz A et al.; We studied nine solid and two liquid media for their suitability to select Aeromonas and Plesiomonas spp . from human stools, using artificially contaminated samples as well as 254 samples from outpatients with and without diarrhea . Media with optimal sensitivity and specificity for Aeromonas spp . were alkaline peptone-water, Trypticase soy broth with ampicillin, inositol-brilliant green-bile salts agar, dextrin-fuchsin-sulfite agar, xylose-sodium desoxycholate-citrate agar, and Pril-xylose-ampicillin agar . For Plesiomonas sp., alkaline peptone-water and inositol-brilliant green-bile salts agar were optimal . Four strains of Aeromonas spp . were detected in patient samples with these media. Dev Comp Immunol, 1983 Summer, 7(3), 473 - 82 Characterization of immunoglobulins from the brown bullhead (Ictalurus nebulosus) produced against a naturally occurring bacterial pathogen, Aeromonas hydrophila; Isbell GL et al.; The primary immune response in the brown bullhead (Ictalurus nebulosus) to intramuscularly injected, chloroform-killed Aeromonas hydrophila reached an agglutination titer of 128 in 3 wk, and the response to the bacteria plus adjuvant reached a titer of 512 in 5 wk . Anti-Aeromonas hydrophila antibodies from brown bullheads were excluded from Sephadex G-200 and had an immunoelectrophoretic migration pattern toward the cathode . Cleavage of the macromolecule by 2-ME reduction and iodoacetamide alkylation yielded subunits that were resumptively heavy chains of about 50,500 daltons and light chains of about 22,500 daltons . Bullhead antibodies were assumed to be tetrameric in configuration and therefore to have an approximate molecular weight of 600,000 daltons assuming a J chain is present in both early (6 wk) and late (20 wk) immune sera . The agglutinating activity of the antibody was completely eliminated by exposure to 65 degrees C for 30 min . Immunoelectrophoresis showed a single antibody component that moved toward the cathode . The structure and molecular weight of bullhead antibodies appears similar to that observed in channel catfish and other closely related teleost fish. Rev Argent Microbiol, 1983, 15(1), 33 - 9 {Study of Aeromonas (motile) in the sewage from the city of Buenos Aires and water from the RÃo de la Plata}; Parodi GS et al.; The incidence of motile aeromonas in the sewage of Buenos Aires city and in the water of the Rio de la Plata was investigated . Eight morphological and biochemical properties were established for the classification of bacteria in the genus Aeromonas . These properties adapted from Popoff and Veron (19) permitted us to classify the isolated strains into two species: A . hydrophila and A . sobria . In the water of the Rio de la Plata, of 27 isolated strains 24 were classified as A . hydrophila and 1 as A . sobria . The co-existence of two species of motile aeromonas is discussed . The usefulness of several isolation media and the temperature of incubation are emphasized. Trans R Soc Trop Med Hyg, 1983, 77(5), 699 - 701 A modified infant mouse assay for bacterial enterotoxins; Berry RJ et al.; The reproducibility of the infant mouse assay for Escherichia coli ST and heat-labile enterotoxins of Aeromonas spp . is improved if both intestinal weight to remaining body weight ratio (IW/RBW) and the amount of diarrhoea produced are considered as criteria for classifying enterotoxigenic strains . Animals with profuse diarrhoea may have IW/RBW ratios below the widely accepted critical value for a positive test . Using pools of supernatants from broth cultures of three different strains of E . coli, 15% of ST producers would have been regarded as negative using IW/RBW ratio as the only criterion of a positive test . In testing single supernatants, 25% of ST producing E . coli would not have been correctly classified using IW/RBW alone . A scoring system which incorporates IW/RBW ratios and the amount of diarrhoea produced improves the usefulness of the test by allowing clear separation of positive and negative strains . The scoring system is also applicable to older mice for assay of E . coli ST so that a wider age range of mice can be used allowing increased use of animal facilities. Toxicon, 1983, 21(6), 805 - 15 Survival of cultured cells after functional and structural disorganization of plasma membrane by bacterial haemolysins and phospholipases; Thelestam M et al.; Lesions were induced in the plasma membranes of cultured human fibroblasts by membrane damaging toxins of bacterial origin (haemolysins) . Structural disorganization of the membrane was measured as leakage of a radiolabelled small cytoplasmic marker and functional membrane damage was measured as decreased uptake of aminoisobutyrate . Cell survival was scored 24 and 48 hr later by measuring uptake of Trypan Blue and by light microscopical evaluation of cell morphology and proliferation . The membrane damage induced by most bacterial toxins was reversible upon removal of the toxin, since toxin-treated cells recovered and excluded Trypan Blue although they had been permeable to the dye immediately after the toxin treatment . Among ten bacterial toxins tested, the only exception of this general behavior was the Aeromonas hydrophila beta-haemolysin, which irreversibly damaged human fibroblasts . Thus, the action of bacterial haemolysins on cultured cells generally seems restricted to a plasma membrane permeabilization, which is reversible regardless of the mechanism of membrane damaging action of the toxin or of the relative size of the structural lesions induced . Furthermore, the use of Trypan Blue uptake as a measure of cell death caused by membrane damaging agents appears to be of limited value. Lancet, 1982 Dec 11, 2(8311), 1304 - 6 Aeromonas-associated gastroenteritis; Gracey M et al.; Enterotoxigenic Aeromonas spp . were isolated from 118 (10.2%) children with diarrhoea and 7 (0.6%) of those without diarrhoea in a prospective, year-long study of 1156 children with gastroenteritis and the same number of age and sex matched controls . In Perth, Western Australia, aeromonas-associated diarrhoea is distinctly seasonal with a sharp summer peak . The disease most commonly presents in children under two years of age as watery diarrhoea of short duration and mild fever which require no specific treatment . In more than one-third of patients diarrhoea lasted for over 2 weeks and in almost one-quarter there was a dysentery-like illness . In some patients with aeromonas-associated diarrhoea the clinical features could be regarded as suggestive of ulcerative colitis. Arch Microbiol, 1982 Dec 3, 133(4), 295 - 9 Enzymes of arginine utilization and their formation in Aeromonas formicans NCIB 9232; Stalon V et al.; In Aeromonas formicans two inducible catabolic pathways of L-arginine have been characterized . The arginine decarboxylase is induced by arginine which also induces the three enzymes of the arginine deiminase pathway but only in stress conditions such as a shift from aerobic growth conditions to very low oxygen tension . Addition of glucose to medium containing arginine leads to repression of the enzymes involved in the arginine deiminase pathway while exogenous cAMP prevents that repression of enzyme synthesis by glucose . This suggests that the induction of arginine deiminase pathway is regulated by carbon catabolite repression and the energetic state of the cell. Appl Environ Microbiol, 1982 Dec, 44(6), 1463 - 5 Isolation of Chromobacterium spp . from foods, soil, and water; Koburger JA et al.; Chromobacterium violaceum, a soil and water inhabitant, has been implicated in human disease with a high mortality rate, particularly in the southeastern United States . The psychrotrophic Chromobacterium lividum has been isolated from foods, water, and soil, but is not considered pathogenic . To determine the distribution of Chromobacterium spp . in soil, water, and foods in the Gainesville area, we evaluated Bennett, Ryalls and Moss, and Aeromonas membrane agars for their ability to recover these organisms from various samples when incubated at 25 or 35 degrees C . Bennett agar was best for the isolation of both species when incubated at 25 degrees C; however, at 35 degrees C, Aeromonas membrane agar gave the highest recoveries of C . violaceum . C . violaceum was recovered only from soil and water, whereas C . lividum was frequently recovered from foods as well as soil and water. Clin Orthop, 1982 Nov-Dec, (171), 117 - 20 Aeromonas hydrophila infection complicating an open tibial fracture . A case report; Simodynes EE et al.; Aeromonas hydrophila is a gram-negative bacterium that commonly inhabits soil and stagnant water . On extremely rare occasions, the organism can cause an aggressive, rapidly spreading, necrotizing infection in humans . The systemic signs of high fever, tachycardia, and elevation of the white blood cell count appear within 24 hours of wound contamination . If the wound is obscured by a cast, these signs erroneously may be attributed to a respiratory problem, e.g., atelectasis or fat metabolism . The organism is not usually sensitive to penicillin or cephalothin . The key to success for saving the extremity appears to be early aggressive debridement . Early diagnosis requires prompt wound inspection as soon as clinical signs of sepsis appear. J Clin Microbiol, 1982 Oct, 16(4), 692 - 6 Enzymatic characterization of Aeromonas hydrophila complex by the API ZYM system; Waltman WD 2nd et al.; Enzymatic characterization of 48 Aeromonas hydrophila complex isolates from various sources was determined with the API ZYM system (Analytab Products, Plainview, N.Y.) . All isolates lacked valine and cystine aminopeptidases, chymotrypsin, alpha-mannosidase, alpha-fucosidase, alpha-galactosidase, and beta-glucuronidase but possessed caprylate esterase-lipase, leucine aminopeptidase, acid phosphatase, phosphoamidase, and N-acetyl-beta-glucosidase . Variability was found in the presence of alkaline phosphatase, butyrate esterase, myristate lipase, trypsin, beta-galactosidase, alpha-glucosidase, and beta-glucosidase . No significant differences were evident among the enzymatic profiles of isolates from various sources. Antimicrob Agents Chemother, 1982 Sep, 22(3), 513 - 4 In vitro susceptibilities of Aeromonas hydrophila against new antibiotics; Fainstein V et al.; The antibiotic susceptibilities of 16 clinical isolates of Aeromonas hydrophila obtained from cancer patients with septicemia were studied . Of the new beta-lactam antibiotics tested, azthreonam and moxalactam were the most active, followed by cefoperazone, cefotaxime, and ceftizoxime . Excellent activity was demonstrated by chloroamphenicol, tetracycline, aminoglycosides, and trimethoprim-sulfamethoxazole . Semisynthetic penicillins had no appreciable activity against this organism. J Gen Microbiol, 1982 Jun, 128(Pt 6), 1249 - 64 Numerical taxonomy of psychrotrophic pseudomonads; Molin G et al.; The taxonomy of 218 psychrotrophic pseudomonad strains (200 field strains from meat and 18 type and reference strains) was numerically studied by 174 biochemical and physiological tests . All strains were Gram-negative rods, oxidative positive and motile by means of one or more polar flagella . The strains clustered into 15 groups, of which 9 were regarded as major clusters . The major clusters were designated as Pseudomonas fragi (112 strains), P . fluorescens biotype III (7 strains), P . fluorescens biotype I (16 strains) . P . aureofaciens/chlororaphis (3 strains), P . fluorescens biotype II (3 strains), P . putida biotype I (4 strains), Alteromonas putrefaciens (10 strains) and Aeromonas hydrophila biotype I (5 strains) . One major cluster, containing 21 strains (cluster 2), was left unassigned . The phenotypic data indicate that this cluster might represent a new species . The P . fluorescens/P . putida complex matched closely the descriptions of Stanier et al . (1966), but the two largest clusters (1 and 2) were not in agreement with any species described in the eighth edition of Bergey's Manual of Determinative Bacteriology . Cluster 1 included the type strain (ATCC 4973) of the hitherto incompletely described P . fragi . A simplified scheme for the separation between P . fragi, P . fluorescens, P . putida and cluster 2 is presented. Infect Immun, 1982 Jun, 36(3), 1069 - 75 Role of surface components in serum resistance of virulent Aeromonas salmonicida; Munn CB et al.; The ability of virulent strains of Aeromonas salmonicida to resist the bactericidal activity of serum was quantitated . The A . salmonicida strains tested included virulent strains, mutants lacking the major surface A-protein, and mutants lacking A-protein and having a modified lipopolysaccharide structure . The sera evaluated included normal human, rabbit, and trout sera, immune trout serum, and immune rabbit serum containing antibodies to A-protein and lipopolysaccharide . Virulent strains of A . salmonicida displayed high or intermediate resistance to the bactericidal activity of complement both in the presence and absence of specific antibody . In normal sera, both A-protein and lipopolysaccharide contributed to serum resistance . In immune trout serum, the protection was conferred by A-protein. J Exp Zool, 1982 May 1, 220(3), 277 - 87 The effect of primary and secondary immunization on the lymphoid tissues of the carp, Cyprinus carpio L; Secombes CJ et al.; Mirror carp immunized with human gamma globulin (HGG) in Freund's complete adjuvant (FCA) show a proliferative response involving cells whose cytoplasm stains deep red with methyl green-pyronin (pyroninophilic cells) . This response occurs particularly in the haemopoietic parenchyma of the pronephros and mesonephros . It peaks at week 3, with the formation of clusters of pyroninophilic cells in the pronephros . Immunization with Aeromonas salmonicida elicited a less intense pyroninophilic response but caused a larger increase in pigment-containing cells . After a secondary immunization with HGG in FCA, a distinct response was observed in the spleen: Pyroninophilic cells collected within the ellipsoid sheaths in large numbers and formed nodules . The reticulum of such nodules acquired spherical proportions and resembled the white pulp reticulum of the tetrapod spleen . The roles of such pyroninophilic cells and the possibility that aggregations of them may be functionally analogous to homoiotherm germinal centres are discussed. J Biochem (Tokyo), 1982 Apr, 91(4), 1181 - 6 Purification and characterization of a novel exo-beta-mannanase from Aeromonas sp . F-25; Araki T et al.; A novel exo-beta-mannanase (1,4-beta-D-mannan mannobiohydrolase) was isolated from the culture fluid of strain No . F-25 of Aeromonas hydrophila subspecies anaerogenes, and purified about 4,000-fold by ammonium sulfate precipitation and successive co.umn chromatographies . The final enzyme preparation appeared to be homogeneous on polyacrylamide gel electrophoresis . The enzyme hydrolyzed the beta-1,4-mannan link in polysaccharides of three or more beta-1,4-linked D-mannose units . The enzyme had a molecular weight of 64,000, pI of 5.9, pH optimum of 6.0, and was stable in a pH region of 5.0 to 8.5 and at temperatures below 45 degrees C . The Km values of the enzyme were 5.1 X 10(-4) M for mannotriose, 2.4 X 10(-4) M for mannotetraose and 1.3 X 10(-4) M for mannopentaose . The enzyme attacked codium and coffee mannans to give only mannobiose . Mannobiosyl- and mannotetraosyl-mannitol were hydrolyzed to produce mannobiose and mannitol, while mannobiose and mannosylmannitol were released from mannotriosylmannitol . The enzyme did not act on mannobiose, p-nitrophenyl-beta-D-mannoside, konjac glucomannan, or guar gum galactomannan . Furthermore, the enzyme catalyzed a transglycosylation reaction. J Biol Chem, 1982 Mar 25, 257(6), 3320 - 5 Purification and partial characterization of a bacterial phospholipid: cholesterol acyltransferase; Buckley JT et al.; A glycerophospholipid:cholesterol acyltransferase has been purified to near homogeneity from cell-free culture supernatants of Aeromonas salmonicida . The characteristics of the enzyme distinguish it from bacterial phospholipases; however, it shares several properties with the lecithin:cholesterol acyltransferase of mammalian plasma . Thus, the enzyme inhibits 2-positional specificity as an acyltransferase and it will act as a phospholipase A2 in the absence of cholesterol . Furthermore, it has no divalent cation requirement and it is stimulated both by albumin and by human apolipoprotein A-I . Unlike the mammalian acyltransferase, however, the bacterial enzyme is not specific for phosphatidylcholine and in addition it can use human erythrocyte membranes as substrates . Similar to Naja naja phospholipase A2, it acts asymmetrically on intact erythrocytes. Biosci Rep, 1982 Mar, 2(3), 169 - 75 Oxidation, photosensitized by certain diketones, of enzymes and protection against such oxidation by histidine derivatives; Makinen KK et al.; Bovine milk lactoperoxidase, eel acetylcholinesterase, and Aeromonas aminopeptidase were photooxidized and inactivated in broad-spectrum visible light in the presence of 2,3-butanedione and 1-phenyl-1,2-propanedione . Methylglyoxal caused similar effects at 254 nm . 2-Thiol-L-histidine and 3-methyl-L-histidine protected the enzymes against photoinactivation more effectively then N3-, even at a molar ratio of 2:1 (protector to enzyme) . These compounds also delayed the photoinactivation of acetylcholinesterase, induced by ultraviolet light. Acta Trop, 1982 Mar, 39(1), 73 - 7 The use of aerolysin toxin as an aid for visualization of low numbers of African trypanosomes in whole blood; Pearson TW et al.; A method was developed for detection of low numbers of African trypanosomes in whole blood . The method is based on selective lysis of erythrocytes and leukocytes by aerolysin, a toxin produced by the bacterium Aeromonas hydrophila . African trypanosomes do not bind the toxin and their viability and motility are therefore unaffected by this treatment. Biochim Biophys Acta, 1982 Jan 22, 684(2), 249 - 54 Cell surface of the fish pathogenic bacterium Aeromonas salmonicida . II . Purification and characterization of a major cell envelope protein related to autoagglutination, adhesion and virulence; Evenberg D et al.; The purification of the major protein of the membrane fraction of an autoagglutinating strain of Aeromonas salmonicida is described . This protein, designated as additional cell envelope protein, is water-insoluble, has a molecular weight of about 54 000 and its amino terminal sequence is H2N-Asp-Val-Leu-Leu . Neither sulphur-containing amino acids nor sugar residues were detected . Its amino acid composition, which shows that the additional cell envelope protein is hydrophobic in nature, is remarkably similar to those of various proteins known to be present in additional surface layers of other bacteria, to the adhesive K88 fimbriae of enteropathogenic Escherichia coli and to a pore protein of the outer membrane of E . coli K12. Dev Comp Immunol, 1982 Fall, 6(4), 675 - 82 Molluscan immunobiology: isolation of an Aeromonas formicans which escapes the internal defense system of Helix pomatia; Bayne CJ; Bacterial infections are surprisingly rare in wild populations of gastropod molluscs . A strain of Aeromonas formicans, which has now been isolated, kills Helix pomatia, a land snail, when injected at doses greater than 10(6) viable cells g-1 snail weight . Koch's postulates were fulfilled with this organism . Initial clearance of Aeromonas from the circulation was followed within hours by a bacteremia; since neither culture supernatants, killed cells nor cell extracts killed Helix, there is evidently no specific lethal toxin; death appeared to be due to a general septicemia. Toxicon, 1982, 20(2), 397 - 407 Aeromonas hydrophila toxins - intestinal fluid accumulation and mucosal injury in animal models; Ljungh A et al.; Strains of Aeromonas hydrophila were earlier shown to produce a heat-labile enterotoxin and two cytolytic toxins, alpha- and beta-haemolysin . These investigations have been extended . When separated from the cytolysins, the enterotoxin elicited fluid accumulation in rabbit intestinal loops . The electrolyte and albumin content of the fluid was similar to that of cholera toxin . The enterotoxin was non-injurious to the mucosa . Purified hemolysins did not give a positive loop test . They produced hemorrhagic enteritis with leakage of small amounts of hemorrhagic fluid . In electrolyte and albumin content this fluid differed from the fluid elicited by the enterotoxin . Prostaglandin inhibitors did not reduce the diarrheal response to Aeromonas enterotoxin . The cAMP inhibitor chlorpromazine reduced the fluid accumulation in rat and mice intestinal loops by 60% . Cholera toxin and Aeromonas enterotoxin may have a common pathway in the elicitation of intestinal fluid accumulation . By passage in intestinal loops, strains of A . hydrophila could regain lost enterotoxicity . Experimental diarrhea could not be induced in rabbits and rats with various enterotoxigenic strains of Aeromonas. Toxicon, 1982, 20(1), 159 - 63 Two membrane damaging toxins from Aeromonas hydrophila; Thelestam M et al.; The effects of two hemolysins (alpha and beta) from Aeromonas hydrophila on human lung fibroblasts were investigated . The toxins differed with respect to relative size of lesions induced in the plasma membrane, morphological effects, reversibility of effects and adsorption to fibroblasts . The effect of alpha-hemolysin appears to be restricted to the plasma membrane level, whereas the beta-hemolysin is strongly cytotoxic and probably acts on some intracellular target in addition to the primary target, the plasma membrane. J Foot Surg, 1982 Spring, 21(1), 45 - 53 Aeromonas hydrophilia: a rare and potentially life-threatening pathogen to humans; Weinstock RE et al.; The authors discuss the diagnosis, symptoms, and treatment of infections resulting from Aeromonas hydrophilia, and uncommon pathogen that is being reported with increasing frequency and may be serious to man . They present the case history of a 38-year-old male and emphasize the importance of prompt and proper treatment. Clin Exp Immunol, 1982 Jan, 47(1), 34 - 42 Immunological cross-reactivity of enterotoxins of Aeromonas hydrophila and cholera toxin; James C et al.; Pre-incubation with anticholera toxin (ACT) significantly reduced intestinal secretion induced by cell-free broth preparations of heat-labile toxins (LT) of Escherichia coli and Aeromonas hydrophila in jejunal perfusion experiments in rats in vivo . Pre-incubation with ACT also prevented cytotoxicity by E . coli LT in the Y1 cell culture system . Pre-incubation had no effect on cytotoxicity in Y1 and L132 cell lines or on haemolytic activity with cell-free preparations of A . hydrophila . In another series of experiments rats were immunized with cholera toxin given as an intraperitoneal priming dose followed 12 days later by intraduodenal boosting . Immunization significantly protected against net intestinal fluid secretion induced by enterotoxigenic E . coli and A . hydrophila and by cholera toxin. J Clin Microbiol, 1982 Jan, 15(1), 48 - 52 Biochemical characteristics of enterotoxigenic Aeromonas spp; Burke V et al.; Biotypes of Aeromonas spp . correlated well with enterotoxin production in a study of 174 strains . Using biochemical characteristics determined by conventional methods and multitest systems, we correctly classified 93% of the strains with regard to enterotoxin production . Most of the enterotoxigenic strains were Voges-Proskauer (VP) positive and did not hydrolyze arabinose, but VP-positive strains which hydrolyzed arabinose were mainly non-enterotoxigenic . Aeromonas punctata subsp . caviae, which is VP negative and does not oxidize gluconate or produce gas from glucose, was non-enterotoxigenic . Although the number of other VP-negative strains was small, most were enterotoxigenic . Discrimination was improved so that 97% of the strains were correctly classified if the hemolysin assay was used either for all strains or for only the VP-positive, arabinose-positive and VP-negative, non-A . punctata subsp . caviae strains . Because the proposed classification system does not require facilities for carrying out in vivo assays such as suckling mouse or ileal loop methods, the identification of enterotoxigenic Aeromonas strains should be possible in diagnostic laboratories and will facilitate epidemiological studies of the role of these organisms in acute diarrhea. Toxicon, 1982, 20(4), 787 - 94 Cytotonic enterotoxin from Aeromonas hydrophila; Ljungh A et al.; Aeromonas hydrophila produces two hemolysins and an enterotoxin during growth . Enterotoxin, separated from the hemolysins, gave positive reactions in the rabbit intestinal loop test, the rabbit skin test and the adrenal Y1 cell test . Neutralization experiments in the rabbit loop, rabbit skin and Y1 cell tests failed to demonstrate any immunological relationship between Aeromonas enterotoxin and cholera toxin or Escherichia coli heat-labile enterotoxin . Prior incubation of Aeromonas enterotoxin with gangliosides did not inhibit the positive test results in these systems . A co-agglutination test with antiserum to purified cholera toxin was negative for Aeromonas enterotoxin, which therefore seems to be immunologically distinct from cholera toxin . The Aeromonas enterotoxin induced steroid secretion in adrenal Y1 cells and increased the intracellular cyclic adenosine monophosphate (cAMP) content of Y1 cells as well as of rabbit intestinal epithelial cells . It thus seems to act via the adenylate cyclase-cAMP pathway and should be classified as a cytotonic enterotoxin according to the classification of Keusch and Donta (1975). Aust J Exp Biol Med Sci, 1981 Dec, 59(Pt 6), 753 - 61 Exotoxins of Aeromonas hydrophila; Burke V et al.; Eighty of 103 strains of Aeromonas hydrophila cultured at 100 rev./min produced heat-labile enterotoxins detected using the suckling mouse assay . Results in intestinal perfusion agreed with the suckling mouse test in all strains tested by both methods . Enterotoxic activity correlated with haemolysin and cytotoxin production, but 4% of strains would have been wrongly classified using haemolysin assay in place of the suckling mouse test and 11% misclassified on the basis of cytotoxin assay . There was a significant association between haemolytic and cytotoxic activity, but 15% of strains produced only one of these toxins . Haemolysin, cytotoxin and enterotoxin were not always associated in a given isolate . The time of appearance of exotoxins during bacterial growth and the effects of dialysis, heating and proteolytic enzymes also suggest that haemolysins, cytotoxins and enterotoxins of Aeromonas hydrophila are separate toxins and not different manifestations of the same toxin. Acta Pathol Microbiol Scand {B}, 1981 Dec, 89(6), 387 - 97 Separation and characterization of enterotoxin and two haemolysins from Aeromonas hydrophila; Ljungh A et al.; Aeromonas hydrophila produces two haemolysins, now designated alpha- and beta-haemolysin (formerly aerolysin or cytotoxic protein), and one enterotoxin . These toxins were separated and purified by isoelectric focusing and gel chromatography . Alpha- and beta-haemolysin differ with regard to prerequisites for their elaboration, such as selection of A . hydrophila strains and temperature and time for cultivation . The nature of their lytic effects on erythrocytes and toxic effects on tissue culture cells differs significantly . Alpha- but not beta-haemolysin was inactivated by reducing agents and activated by oxygen, while beta-haemolysin was more resistant than alpha-haemolysin to proteolytic enzymes but was inactivated by crude gangliosides . When separated from the two haemolysins, the enterotoxin gave positive reactions in the rabbit intestinal loop test, the rabbit skin and the adrenal Y1 cell test, though the sensitivity of the Y1 cell was low as compared with cholera toxin and E . coli LT toxin . No cytotoxic effects were obtained in HeLa cells. Infect Immun, 1981 Dec, 34(3), 949 - 56 Membrane-damaging and cytotoxic effects on human fibroblasts of alpha- and beta-hemolysins from Aeromonas hydrophila; Thelestam M et al.; The effects of two hemolysins (alpha and beta) from Aeromonas hydrophila on human lung fibroblasts were investigated . The toxins differed distinctly in regard to the morphological changes they produced . The alpha-hemolysin caused rounding of the cells . The beta-hemolysin caused a striking vacuolization of the cytoplasm in cells which remained spread out on the growth surface . The toxins also differed as to relative size of the initial lesions they induced in the fibroblast membrane, scored by leakage of different-sized cytoplasmic markers . The alpha-hemolysin induced larger lesions than did the beta-hemolysin . It was indirectly demonstrated that the alpha-hemolysin did not bind, or bound only transiently, to the fibroblasts . By contrast, the beta-hemolysin bound rapidly and firmly . The cytopathogenic response to the alpha-hemolysin was reversible, whereas cells treated with small amounts of the beta-hemolysin for only 1 min invariably died within a few hours . Thus, the two hemolysins from A . hydrophila, despite many biochemical similarities, show essential dissimilarities in their interactions with cultured cells. J Med Microbiol, 1981 Nov, 14(4), 401 - 8 Detection of enterotoxins of Aeromonas hydrophila by a suckling-mouse test; Burke V et al.; The suckling-mouse assay was reliable for detecting enterotoxigenic strains of Aeromonas hydrophila when standard conditions for growth and toxin testing were used . Enterotoxins were produced by bacteria grown in tryptone soya broth supplemented with yeast extract and aerated by shaking in an environmental incubator or water bath . When culture supernates together with dye were administered intragastrically to mice less than 6 days old, the presence of enterotoxin was assessed on the basis of a scoring system that incorporated the ratio intestinal weight: remaining body weight, and production of diarrhoea . This method should facilitate the detection of enterotoxigenic strains of Aeromonas in epidemiological studies. J Wildl Dis, 1981 Oct, 17(4), 505 - 10 A bacterial disease of perch (Perca fluviatilis L.) in an alpine lake: isolation and preliminary study of the causative organism; Michel C; An epizootic among perch (Perca fluviatilis L.) occurred during the summer and fall of 1979 in an alpine lake (Lake Annecy, Haute-Savoie) in France . Hemorrhagic and ulcerative clinical signs were associated with the height of the mortality . A Gram-negative, non-motile, slow-growing bacterium was isolated from skin lesions is diseased fish . Aeromonas hydrophila often was present . Since the nonmotile bacterium was suspected to be the etiological agent, its characteristics and pathogenicity were determined . The bacterium was pathogenic to perch, possibly pathogenic to rainbow trout, and non-pathogenic to carp . It could be reisolated from infected fish, but its physiologic and biochemical properties have not been assessed to determine the taxonomic position. J Bacteriol, 1981 Oct, 148(1), 333 - 40 Loss of virulence during culture of Aeromonas salmonicida at high temperature; Ishiguro EE et al.; The effect of growth temperature on the loss of virulence of the fish pathogen Aeromonas salmonicida was investigated . Three virulent strains were grown in Trypticase soy broth at temperatures ranging from 22 to 30 degrees C . Growth at a higher-than-optimal temperature (26 to 27 degrees C for the three strains studied) resulted in the selection of spontaneous attenuated derivatives in the initial bacterial population . For example, virulent bacteria represented less than 10% of the population of a culture grown at 30 degrees C, and attenuated derivatives were easily isolated by streaking the culture on solid medium and picking single colonies . Virulent strains autoaggregated during growth and possessed a cell wall layer (A-layer) external to the outer membrane, as previously described . Attenuated strains did not autoaggregate and did not possess the A-layer . The A-layer apparently shielded bacteriophage receptors and a mannose-specific yeast agglutinin located in the outer membrane . Thus, virulent strains exhibited impaired adsorption of phages, whereas attenuated strains were phage sensitive . Furthermore, attenuated strains agglutinated yeast cells but virulent strains did not . The attenuated strains had higher maximum growth temperatures than their virulent parent strains, and this accounts for their selection at high temperatures . It is proposed that the A-layer contributes significantly to the physical properties of the A . salmonicida cell envelope and that these physical properties of the A . salmonicida cell envelope and that these physical change upon loss of the A-layer to permit growth at a higher-than-usual temperature. Can J Microbiol, 1981 Oct, 27(10), 1114 - 22 Extracellular virulence factors of Aeromonas hydrophila in fish infections; Allan BJ et al.; Aeromonas hydrophila NRC 505 produced extracellular substances which were capable of causing pathological effects when injected into trout . Proteolytic activity and haemolytic activity of the extracellular products, and the effect on fish, were lost on heating . The extracellular substances from strain G35, a protease-deficient mutant, were significantly more toxic to both rainbow trout (Salmo gairdneri) and speckled trout (Salvelinus fontinalis) than the analogous preparation from the parental strain NRC 505 . The response of speckled trout injected intraperitoneally with dilutions of the extracellular preparations implicates haemolytic activity as a significant lethality factor. Am J Physiol, 1981 Sep, 241(3), R198 - 202 Pyrogens fail to produce fever in a cordylid lizard; Laburn HP et al.; We investigated the effects on body temperature of the lizard Cordylus cataphractus of intracardiac injections of leucocyte pyrogen (LP) synthesized from rabbit blood and of killed Aeromonas hydrophila, a gram-negative bacterium reputed to be pathogenic in lizards . Lizards were placed in a photothermal gradient that allowed them to select a preferred body temperature following the injections . Neither injection of 0.5 ml rabbit LP nor of 4 X 10(9) organisms of A . hydrophila in 0.2 ml sterile saline caused body temperature of lizards to differ from that of control lizards injected with sterile saline . Following injection of these solutions in the lizards placed in a thermal gradient where ambient temperature ranged from 20-88 degrees C, body temperature was maintained between 32 and 34 degrees C . Pyrogens failed to elevate body temperature even when body temperature was elevated artificially to 36 degrees C before injection . We conclude that C . cataphractus does not respond with fever to either rabbit LP or A . hydrophila . Fever may not be ubiquitous even among lizards. J Bacteriol, 1981 Sep, 147(3), 1077 - 84 Purification and disposition of a surface protein associated with virulence of Aeromonas salmonicida; Kay WW et al.; Virulent strains of Aeromonas salmonicida observed by electron microscopy were characterized by an outer layer exhibiting a tetragonal repeat pattern . Attenuated strains had a 2.5 X 10(3)- to 5 X 10(3)-fold reduction in virulence and lost the outer layer, autoaggregating properties, and a 49-kilodalton protein (A protein) simultaneously . The A protein is the major protein component of outer membrane fractions of virulent strains . A variety of radiolabeling studies showed that this protein was surface localized and that it provided an effective barrier against iodination of other outer membrane proteins with either lactoperoxidase or diazoiodosulfanilic acid; A protein was not labeled with lactoperoxidase but was specifically labeled with diazoidosulfanilic acid . The A protein was purified by selective extraction with detergent and guanidine hydrochloride, and its amino acid composition was determined . The properties of A protein are compared with those of other bacterial surface layer proteins. Infect Immun, 1981 Sep, 33(3), 728 - 33 Medium for the accumulation of extracellular hemolysin and protease by Aeromonas hydrophila; Riddle LM et al.; A medium for the accumulation of extracellular hemolysin (300 to 1,600 hemolytic units per ml) and protease (2 to 3 proteolytic units per ml) was developed for an anaerogenic strain of Aeromonas hydrophila . In this medium, growth yields were less but levels of accumulated toxin were greater or equivalent when compared with the same responses in brain heart infusion and nutrient broths . The medium was considered to be partially defined since the conditions for maximum observed hemolysin accumulation (1,600 hemolysin units per ml) were not identified . The results showed that iron and zinc contributed to the control of the extracellular accumulation of both toxins . Whereas iron exerted an inhibitory effect, zinc stimulated the accumulation of both toxins. Appl Environ Microbiol, 1981 Jul, 42(1), 56 - 60 Serogrouping of motile Aeromonas species isolated from healthy and moribund fish; Leblanc D et al.; A total of 195 strains of motile Aeromonas isolated from fish were characterized as Aeromonas hydrophila and Aeromonas sobria . In view of the frequency of isolation and the importance of motile Aeromonas species as fish pathogens, a serological classificaton of these organisms was attempted . Antisera were prepared in rabbits against formalinized whole cell suspensions and against boiled cells of 12 different isolates . Seventy-six strains could be grouped by tube agglutination with whole cells as antigen and anti-whole cell antiserum . However, only 39 strains were typable with anti-O serum . Differentiation was made between heat-stable antigens and heat-labile antigens which did not block the O agglutination reaction . The same heat-labile antigen could be associated with different heat-stable particulate antigens, and a relationship was observed between the heat-stable particulate antigens and the virulence of A . hydrophila for fish . In addition to these two types of antigen, motile Aeromonas possessed heat-stable soluble antigens which could be detected by indirect hemagglutination . One strain seemed to possess various heat-stable soluble antigens; so far, however, it does not appear to be feasible to use these antigens for serology . Finally, we also observed cross-reactions between some A . hydrophila and A . sobria strains. South Med J, 1981 Jul, 74(7), 901 - 2 Nosocomial Aeromonas hydrophila cellulitis and bacteremia in a nonimmunocompromised patient; Lynch JM et al.; An elderly man, without heat in his home for two days, presented with cold, painful, swollen feet . Second-degree frostbite was present . After having moist packs applied to his feet for five days, the patient became febrile and hypotensive, and wet gangrene necessitated left below-knee and right above-knee amputations . Aeromonas hydrophila was isolated from the patient's blood and cultures of the pedal wounds . An etiologic role of the moist pack therapy is postulated. Lab Anim Sci, 1981 Jun, 31(3), 297 - 300 Aeromonas hydrophila infection in Xenopus laevis; Hubbard GB; Aeromonas hydrophila caused severe disease in a group of Xenopus laevis within 3 weeks of receipt . The primary clinical signs were marked pallor of the skin, petechiation, lethargy, anorexia, and edema . The duration of the outbreak was approximately 45 days during which time 21 frogs became sick and 18 died, despite tetracycline therapy . Pale skin, subcutaneous edema and hemorrhages, ascites, and pale livers were seen at necropsy . Aeromonas hydrophila was isolated from skin, and the same organism was isolated in pure culture from skeletal muscle . Tetracycline treatment via stomach tube was effective if given early in the course of the disease . The outbreak was controlled by removing sick frogs, feeding twice per week, changing the water several hours after feeding, and maintaining the frogs where the ambient temperature was 22 degrees C or lower . The pallor of the skin and general malaise were produced experimentally by crowding normal frogs, changing the water infrequently, and increasing ambient temperatures . Mild disease was reproduced experimentally by subcutaneous injection of Aeromonas hydrophila into apparently healthy frogs. J Clin Microbiol, 1981 Jun, 13(6), 1054 - 9 Role of pH in oxidase variability of Aeromonas hydrophila; Hunt LK et al.; Some strains of Aeromonas hydrophila may be oxidase negative or only weakly oxidase positive by the Kovacs method taken from the surface of a differential medium, such as MacConkey agar . Six strains of A . hydrophila, two oxidase variable, one oxidase constant, and three weakly oxidase positive on MacConkey agar, were studied to determine the cause of oxidase variability . The bacteriostatic dyes in MacConkey agar were considered possible inhibitors of the oxidase reaction . The concentration of these dyes was varied from twice the normal concentration in zero . No change in the oxidase reaction of any of the six strains was noted . Carbohydrate utilization was also studied . When lactose was deleted from the MacConkey agar formula, the oxidase-variable and weakly oxidase-positive stains become strongly oxidase positive . When glucose was substituted for lactose in the MacConkey agar formula, all strains became oxidase negative . Substitution of nonfermentable carbohydrates, such as dulcitol or raffinose, returned all strains to the oxidase-positive state . When trehalose, which is utilized by all of the strains, was substituted for lactose, the oxidase-variable strains and two of the three weakly oxidase-positive strains became oxidase negative . The other weakly oxidase-positive strain remained weakly positive and the oxidase-constant strain remained strongly oxidase positive when trehalose was substituted for lactose . Oxidase reactions were found to be negative when the pH of the medium was 5.1 or lower . Negative oxidase reactions could be reversed by raising the pH above 5.2, and positive oxidase reactions could be reversed by lowering the pH to 5.1 . Therefore, the fermentation of lactose in MacConkey agar results in the inhibition of the oxidase reaction . The acid end products of the fermentation of lactose include acetic, formic, lactic, oxaloacetic, pyruvic, and succinic acids. J Clin Microbiol, 1981 Jun, 13(6), 1117 - 8 Rapid oxidase method for testing oxidase-variable Aeromonas hydrophila strains; Hunt LK et al.; A rapid, same-day oxidase test procedure which obviates the problem of false-negative oxidase reactions of Aeromonas hydrophila removed from the surface of differential media such as MacConkey agar is described . This method allows oxidase testing to be performed within 3 h, rather than delaying the oxidase test for an additional 18 to 24 h . This procedure is applicable to any rapidly growing gram-negative rod. Can J Biochem, 1981 Jun, 59(6), 430 - 5 Purification and some properties of the hemolytic toxin aerolysin; Buckley JT et al.; Aerolysin, the hemolytic toxin produced by Aeromonas hydrophila, has been purified by a combination of salt fractionation, gel filtration, and ion-exchange and hydroxyapatite chromatography . The resulting protein has a molecular weight of 51 500 and appears homogeneous by polyacrylamide gel electrophoresis in sodium dodecyl sulphate . It is free of detectable protease and phospholipase activities . The purified protein can be separated into two active components with pIs of 5.39 and 5.46 by isoelectric focusing . Both components are found in the original culture supernatant indicating that the multiplicity is not due to proteolysis during isolation . Purified aerolysin is unstable even at 25 degrees C and its hemolytic action is inhibited by certain reducing agents including ferrous iron and cysteine . It appears to be the only toxin hemolytic to human cells that is produced by A . hydrophila under the conditions described. Am J Physiol, 1981 May, 240(5), R272 - 5 Plasma iron, copper, and zinc in lizard Dipsosaurus dorsalis: effects of bacteria injection; Hacker MR et al.; The effects of inoculation of desert iguanas (Dipsosaurus dorsalis) with heat-killed Aeromonas hydrophila on the plasma concentrations of iron, copper, and zinc, and the total iron-binding capacity have been determined . Plasma iron concentration and total iron-binding capacity fell significantly in inoculated lizards maintained at temperatures corresponding to those selected during fever . Plasma copper concentration did not change in response to inoculation (as determined at 24 h postinjection) . Plasma zinc concentration fell in inoculated lizards regardless of whether the lizards were maintained at temperatures corresponding to those selected by afebrile or febrile lizards . There were no effects of varying the zinc concentration (corresponding to those observed in noninfected lizards, infected lizards, or at subnormal levels) on the in vitro growth rate of A . hydrophila . We hypothesize that the reduction in plasma zinc observed in infected mammals, and now in infected lizards, may have an effect (perhaps by some indirect pathway) on the in vivo growth rate of A . hydrophila. Appl Environ Microbiol, 1981 Apr, 41(4), 1052 - 4 Effect of temperature on growth and activity of Aeromonas spp . and mixed bacterial populations in the Anacostia River; Cavari BZ et al.; During the winter months, total bacterial counts in the water column and in the sediment in the Anacostia River were two- to eightfold higher than at other times of the year, whereas Aeromonas spp . decreased in number of several orders of magnitude . This significant decrease in number in the Anacostia River during the cold months of the year can be explained by the low metabolic activity of Aeromonas at low temperatures. Lab Anim Sci, 1981 Apr, 31(2), 166 - 9 Aeromonas hydrophila in wild-caught frogs and tadpoles (Rana pipiens) in Minnesota; Hird DW et al.; Frogs and tadpoles were captured at 14 sites in and near Minnesota during 1978-79 and nearly all appeared healthy . Aeromonas hydrophila was isolated from 94 of 294 (32%) juvenile and adult frogs and from 66 of 104 (63%) tadpoles . Of the isolates from frogs and tadpoles respectively, 68% and 47% were from the intestine only, 12% and 32% were from the intestine and the other sites, and 20% and 21% were from extraintestinal sites only . Isolations were more frequent from frogs collected in March-June than in August-November . Evidence was not found that disease due to Aeromonas hydrophila was a primary cause of declining Rana pipiens populations in Minnesota. J Clin Microbiol, 1981 Apr, 13(4), 769 - 77 Association of Aeromonas sobria with human infection; Daily OP et al.; Fifteen Aeromonas isolates from various human infections and nine isolates from polluted water were identified as either Aeromonas hydrophila or Aeromonas sobria and examined for cytotoxigenicity, enterotoxigenicity, adherence to epithelial cells, and other virulence-associated factors, including proteases, lipases, elastases, and hemolysins . Two groups of organisms (I and II) were distinguishable based on differences in median lethal doses in mice and cytotoxicity for Y-1 adrenal cells . Group I clinical and environmental strains had median lethal doses of less than 10(7) colony-forming units, were cytotoxic, frequently possessed several virulence-associated factors, and had lysine decarboxylase-positive or Voges-Proskauer-positive phenotypes or both . Piliation of Aeromonas was associated strongly with ability to adhere to human buccal cells, and these characteristics were associated with group I strains . Group II clinical and environmental strains had median lethal doses of greater than or equal to 10(7) colony-forming units, were not cytotoxic, and usually were lysine decarboxylase negative or Voges-Proskauer negative or both . Clinical strains in group II exhibited enterotoxigenicity, which was not detected in group II environmental strains . A sobria was more frequently associated with human infections; 13 of the 15 clinical strains were A . sobria, and 2 were A . hydrophila . On the other hand, the majority of the environmental strains (seven of nine) were A . hydrophila. Can J Microbiol, 1981 Mar, 27(3), 330 - 3 A toxigenic profile of Aeromonas hydrophila and Aeromonas sobria isolated from fish; Olivier G et al.; Forty strains of motile Aeromonas were isolated from healthy and diseased fish . These strains were identified as A . hydrophila or a A . sobria . It was found that only strains of A . hydrophila produced a dermonecrotic factor and two zones of hemolysis on blood agar . All the strains of A . sobria tested and 72% of the A . hydrophila were enterotoxigenic . Finally, we observed that only A . hydrophila strains could regularly produce hemolysin at 10 degrees C. J Am Vet Med Assoc, 1981 Feb 15, 178(4), 394 - 5 Unusual disease conditions in pet and aviary birds; Panigrahy B et al.; Ninety percent ot 100% mortality in budgerigar (Melopsittacus undulatus) nestlings from 2 aviaries was attributed to giardiasis . Treatment with dimetridazole in drinking water was effective in controlling mortality . Aeromonas hydrophila infection incriminated in acute deaths of aviary canaries (Serinus canarius) was successfully treated with chlortetracycline . Aeromonas hydrophila also was isolated in pure culture from a toucan (ramphastos toco) with acute nephrosis and a cockatiel (Nymphicus hollandicus) with chlamydiosis (psittacosis) . Coccidiosis associated with hemorrhagic enteritis, diarrhea, and mortality was diagnosed in budgerigars originating from 3 aviaries . Sporulated oocysts from 1 group of budgerigars were identified as Eimera sp . Sulfamethazine in drinking water was an effective treatment. Antimicrob Agents Chemother, 1981 Feb, 19(2), 357 - 8 In vitro susceptibilities of Aeromonas hydrophila to 32 antimicrobial agents; Fass RJ et al.; Minimal inhibitory concentrations of 32 antimicrobial agents for 20 strains fo Aeromonas hydrophila were determined by a microdilution method . Moxalactam was the most active drug tested . All strains were also susceptible to clinically achievable concentrations of mecillinam, cefamandole, cefuroxime, cefotaxime, aminoglycosides (except streptomycin), tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. Can J Microbiol, 1980 Dec, 26(12), 1501 - 3 Aeromonas hydrophila in rainbow trout: relation between virulence and surface characteristics; Mittal KR et al.; Motile Aeromonas isolated from fish were studied for their virulence in fish in relation to some surface characteristics . The results showed that only the most virulent strains of A . hydrophila used in this study shared a common O antigen, did not agglutinate in acriflavine, settled down after boiling, and were resistant to the bactericidal action of fresh normal mammalian serum . The least virulent strains could not be grouped into this O antigenic group, they did not settle after boiling, and were sensitive to the bactericidal effect of serum . It is suggested that agglutination in acriflavine, stability after boiling, and sensitivity to normal fresh serum could be used for screening the Aeromonas isolates for virulence in fish. South Med J, 1980 Nov, 73(11), 1546 - 7 Fulminant wound infection with Aeromonas hydrophila; Deepe GS Jr et al.; Aeromonas hydrophila was isolated from a water-soaked traumatic wound of a previously healthy 16-year-old boy . A progressive necrotizing infection developed despite administration of antibiotics . Aeromonas should be considered in wound infections which are water-related. J Hand Surg {Am} . 1980 Nov;5(6):605. Hand and forearm infections caused by Aeromonas hydrophila; Liseki EJ et al.; This is a report of two cases of hand and forearm infections caused by Aeromonas hydrophila . This organism is resistant to penicillin and most cephalosporins and is found in most freshwater environments . It is recommended that broad-spectrum coverage such as a combination of cephalosporin and aminoglycoside antibiotic be used. Can J Biochem, 1980 Oct, 58(10), 1018 - 25 Identification and characterization of outer membrane fragments released by Aeromonas sp; MacIntyre S et al.; Aeromonas hydrophila and Aeromonas salmonicida were shown to release "blebs" or fragments averaging 20-30 nm in diameter . The protein composition of the fragments was very similar to that of the corresponding outer membrane by sodium dodecyl sulphate--polyacrylamide gel electrophoresis and the fragments were shown to contain phospholipid and lipopolysaccharide . The results therefore indicate that the blebs are derived from the outer membrane of these organisms . Fragments isolated directly by differential ultracentrifugation were indistinguishable from fragments isolated by salt fractionation and gel filtration in chemical composition, protein composition, and density . However fragments isolated directly contained much less glycerophospholipid-cholesterol acyltransferase than those isolated by salt fractionation . The potential usefulness of membrane fragments to the bacteria and as a tool in the study of outer membrane structure and function is discussed. Ann Emerg Med, 1980 Oct, 9(10), 529 - 31 Aeromonas hydrophila infection of a puncture wound; Katz D et al.; Aeromonas hydrophila is a gram-negative organism generally considered a pathogen of low virulence, rarely reported as causing infection in man . Recently it has been recognized as causing infection in wounds . This article reports the case of a patient who suffered a puncture wound while standing in a fresh water lake . He subsequently developed a rapidly progressing cellulitis requiring hospitalization . This organism was cultured from the wound and responded dramatically to appropriate antimicrobial therapy. Appl Environ Microbiol, 1980 Aug, 40(2), 186 - 91 Comparison of nine brands of membrane filter and the most-probable-number methods for total coliform enumeration in sewage-contaminated drinking water; Tobin RS et al.; Nine different brands of membrane filter were compared in the membrane filtration (MF) method, and those with the highest yields were compared against the most-probable-number (MPN) multiple-tube method for total coliform enumeration in simulated sewage-contaminated tap water . The water was chlorinated for 30 min to subject the organisms to stresses similar to those encountered during treatment and distribution of drinking water . Significant differences were observed among membranes in four of the six experiments, with two- to four-times-higher recoveries between the membranes at each extreme of recovery . When results from the membranes with the highest total coliform recovery rate were compared with the MPN results, the MF results were found significantly higher in one experiment and equivalent to the MPN results in the other five experiments . A comparison was made of the species enumerated by these methods; in general the two methods enumerated a similar spectrum of organisms, with some indication that the MF method was subject to greater interference by Aeromonas. Can Med Assoc J, 1980 Jun 7, 122(11), 1270 - 2 Aeromonas hydrophila: analysis of 11 cases; Smith JA; A retrospective analysis of 11 cases in which Aeromonas hydrophila was isolated indicated that the organsim caused local infection in 7 cases and asymptomatic colonization in 4 . There were no cases of septicemia and none of the patients were known to have a malignant disease or immunosuppression . There were no deaths, although three of the patients required amputation of limbs because of myonecrosis . Chloramphenicol and aminoglycosides appeared to be appropriate therapeutic agents. J Physiol, 1980 Jun, 303, 417 - 21 Fever and antipyresis in the crayfish Cambarus bartoni; Casterlin ME et al.; 1 . Normothermic Cambarus bartoni crayfish thermoregulating behaviourally in an electronic shuttlebox prefer a mean temperature of 22.1 degrees C +/- 0.5 S.E . of mean . 2 . Injection of 1% saline, or addition of paracetamol to the ambient water, caused a statistically insignificant decrease in preferred temperature of 0.4 degrees C . 3 . Injection of killed Aeromonas hydrophila bacteria into the abdomen caused a significant mean increase in preferred temperature of 1.8 degrees C (defined as a behavioural fever) . 4 . Injection of A . hydrophila, with paracetamol in the water, resulted in an insignificant increase of 0.1 degrees C above the normothermic temperature; thus paracetamol is antipyretic in crayfish, preventing fever but not altering afebrile thermoregulation . 5 . These results suggest that similar mechanisms may be operating in the neuropharmacological mediation of fever in vertebrates and invertebrates. Lab Anim, 1980 Apr, 14(2), 149 - 51 An eye infection in laboratory lizards associated with an Aeromonas sp; Cooper JE et al.; Laboratory-maintained lizards (Family Lacertidae) kept for studies on thermal biology developed a superficial eye infection associated with Aeromonas liquefaciens . The origin of the infection could not be traced and attempts at therapy were generally unrewarding. Antimicrob Agents Chemother, 1980 Apr, 17(4), 612 - 4 Antimicrobial susceptibility of Aeromonas hydrophila; Overman TL; Minimal inhibitory concentration determinations and disk diffusion and Autobac 1 susceptibility tests were performed on 22 strains of Aeromonas hydrophila . Eleven of the strains had discrepancies between Autobac and disk diffusion or minimal inhibitory concentration results . These discrepancies occurred with the beta-lactam antibiotics, primarily carbenicillin and cephalothin . It is recommended that any strain of A . hydrophila found to be susceptible to any of the beta-lactam antibiotics by using Autobac 1 should be retested by a disk diffusion or minimal inhibitory concentration method. Antimicrob Agents Chemother, 1980 Mar, 17(3), 477 - 83 Isolation of drug-resistant Aeromonas hydrophila from aquatic environments; McNicol LA et al.; Antibiotic-resistant strains of Aeromonas hydrophila have been isolated from the natural environment in the Chesapeake Bay and areas surrounding Dacca and the Matlab region of Bangladesh . The Bangladesh strains carried resistance to chloramphenicol, streptomycin, and tetracycline, and 57% of them had a multiple streptomycin-tetracycline resistance phenotype correlated with the presence of a large plasmid . The Chesapeake Bay strains were resistant to polymyxin B ane tetracycline, but showed neither multiple resistance nor R-factor carriage . Twenty-five percent of the environmental strains were toxigenic in a Y-1 adrenal cell assay . Toxigenicity showed no positive correlation with drug resistance or with plasmid carriage . Environmental areas of heavy human impact appear to be associated with a higher incidence of antibiotic-resistant strains of aeromonads. Arch Microbiol, 1980 Mar, 125(1-2), 83 - 7 Optional production and utilization of polysaccharide by Aeromonas hydrophila; Shaw DH et al.; Glucans from the fish pathogen Aeromonas hydrophila have been extracted and purified by a method utilizing phenol/water followed by sodium deoxycholate rather than the traditional sodium hydroxide extraction . Presence of substantial amounts of these glucans was shown to be dependant on whether or not the substrate contained dextrose, a point which had import because of the low carbohydrate environment in which this species must survive and multiply . These glucans, produced in the log phase, were utilized during the growth period . The structures of the two purified glucans were examined by methylation analysis, periodate oxidation, and enzymatic degradation . The results indicated that A . hydrophila under low-carbohydrate growth conditions produced two similar but distinguishable alpha 1 leads to 4 linked glucans substituted alpha 1 leads to 6 by single monosaccharide residues or short chains to give an amylopectinglucogen type of polysaccharide. Am J Ophthalmol, 1980 Mar, 89(3), 449 - 51 Ocular Aeromonas hydrophila; Smith JA; Aeromonas hydrophila was isolated from the eye swabs of four patients . Two were thought to have definite clinical infection; one had chronic conjunctivitis complicating the wearing of contact lenses, and the other had acute conjunctivitis associated with ectropion and lacrimal duct stenosis . Two patients had no clinical evidence of infection . Both of them had swabs taken at the time of surgery . One had a cataract extraction and the other had a lensectomy and vitrectomy for a penetrating injury . The outcome was satisfactory in the two patients in whom colonization occurred, and in the patient with acute conjunctivitis, all of whom received chloramphenicol with or without gentamicin . The fourth patient was not followed up. Infect Immun, 1980 Mar, 27(3), 938 - 46 Hemagglutination properties and adherence ability of Aeromonas hydrophila; Atkinson HM et al.; Human diarrheal isolates and enterotoxigenic strains of Aeromonas hydrophila are strong hemagglutinators with human blood cells . Sugar inhibition studies and yeast coagglutination tests with 11 selected strains revealed six different hemagglutination mechanisms for this species . These were characterized by inhibition by L-fucose, inhibition by D-galactose, inhibition by D-mannose, and two distinguishable mechanisms which were inhibited by either L-fucose or D-mannose, one being pilus mediated . Inhibition of hemagglutination by another strain required a combination of D-galactose and D-mannose . The hemagglutinating strains also attached well to human blood cells and buccal epithelial cells, with as many as 55% of the cells of a culture attaching successfully . In some cases the attachment to buccal epithelial cells appeared to involve mechanisms different from those used for hemagglutination. Am J Med, 1980 Feb, 68(2), 238 - 42 Aeromonas hydrophila bacteremia in ambulatory immunocompromised hosts; Wolff RL et al.; We observed seven episodes of Aeromonas hydrophila septicemia in five patients . All but one patient had an underlying disease resulting in immunosuppression . All episodes occurred in ambulatory patients whose vocation or avocation had recently caused them to contact water or fish . We hypothesize that infection with this gram-negative bacterium is acquired more frequently from the natural habitat of the organism than from nosocomial sources. Can J Microbiol, 1980 Feb, 26(2), 161 - 8 Immunofluorescence of Aeromonas hydrophila as measured by fluorescence photometric microscopy; Fliermans CB et al.; Strain-specific fluorescent antibodies were prepared for three isolates of Aereomonas hydrophila . These antisera were reacted with 255 other A . hydrophila isolates, and their immunofluorescence was measured quantitatively by photometric fluorescence microscopy . Only 27.5% of the isolates reacted with the prepared antisera which indicated that other undetected serogroups are present . Statistical analyses indicated that the A . hydrophila isolated from aquatic habitats were distinct from the other isolates as measured by immunofluorescence. Acta Microbiol Acad Sci Hung, 1980, 27(1), 63 - 9 Enterotoxigenicity of aeromonas strains in suckling mice; Janossy G et al.; The enterotoxigenicity of 170 Aeromonas strains isolated from different sources (food poisoning, random food sampling, water, faeces) was examined by the suckling mouse test . The strains were grown on Syncaye culture medium covered with sterilized membrane for Kiil-kidney . The culture supernatants were inoculated orally . Ileal loop dilatation was compared to that produced by the international standard enterotoxic Escherichia coli B7A (O148 : H28) and B2C (O6 : H16) strains . Of the 87 Aeromonas hydrophila strains 69, of the 76 Aeromonas punctate subsp . caviae strains 9, the 6 Aeromonas punctata subsp . punctata strains 5, and 1 Aeromonas salmonicida subsp . achromogenes gave a positive reaction in the test. Ann Rech Vet, 1980, 11(4), 375 - 80 Persistence of the virulence of Aeromonas salmonicida strains kept in river sediments; Michel C et al.; The persistence of pathogenicity in two strains of Aeromonas salmonicida maintained in river sediments was studied at different times . Cultures were kept about nine months, and the virulence was compared to its initial value exhibited by the same strain, subcultivated in rainbow trout fingerlings . Trials involved intramuscular injection of comparable doses of bacteria to batches of 30 fish held at 15 degrees C, and recording of subsequent mortalities . No difference was found during the first six months, after which a decrease of pathogenicity resulted in its disappearance before the ninth month . Progressive decrease in incubation temperatures was also exerted to simulate an artificial wintering, but did not alter the evolution of the virulence . The possible role of mud as a source of contamination for fish is discussed. Antibiotiki, 1979 Sep, 24(9), 679 - 84 {Effect of gentamycin in combination with prodigiozan on the immunological reactivity of the body}; Shcherbakova EG et al.; The effect of gentamicin sulphate and its combination will prodigiozan on antibody formation in experiments and the levels of the immunobiologic reactivity of patients with purulent inflammatory processes was studied with a purpose of developing rational schemes of antibiotic therapy of infectious diseases . A decrease in the titers of the antibodies to Aeromonas and the number of antibody-forming cells in the spleen was noted on repeated administration of gentamicin to albino mice in a dose of 20 mg/kg . This was prevented by the use of prodigiozan in a dose of 500 micrograms/kg once every 4 days . The use of gentamicin in patients with purulent inflammatory diseases in doses of 40 or 80 mg twice a day for 7--10 days had no significant effect on the titers of IgA, IgG, IgM, lysozyme blood serum levels, serum bactericidal activity and absorption activity of the peripheral blood neutrophils . Still, it induced a marked suppression of the neutrophil digestive capacity as compared to the initial levels, especially on administration of gentamicin in a dose of 40 mg twice a day . An increase in the level of IgM and no suppression of the neutrophil digestive capacity were noted after completion of the therapy in the patients treated with gentamicin administered in a dose of 40 mg twice a day and prodigiozan administered in a dose of 50 micrograms once every 4 days . It is recommended to use prodigiozan in combinaed therapy with gentamicin for correction of the changes in the specific and nonspecific protective forces of the host. Biochem J, 1979 Aug 15, 182(2), 609 - 11 Identification of isobutyronitrile and isobutyraldoxime O-methyl ether as volatile microbial catabolites of valine; Harper DB et al.; G.l.c.--mass-spectral analysis of headspace above cultures of Aeromonas and Moraxella spp . indicates the presence of isobutyronitrile, isobutyraldoxime O-methyl ether, methacrylonitrile and possibly methacrylaldoxime O-methyl ether . Accumulation of these catabolites is maximal under low oxygen concentrations and is enhanced by enrichment of the medium with valine . Isobutyraldoxime O-methyl ether is established as the compound observed but not identified in previous studies with other bacterial species involved in spoilage of meat and chicken. J Med Microbiol, 1979 Aug, 12(3), 347 - 54 Characterisation and neutralisation of Aeromonas hydrophila enterotoxin in the rabbit ileal-loop model; Dubey RS et al.; Cell-free culture filtrates and crude enterotoxin preparations from six strains of Aeromonas hydrophila caused the accumulation of fluid in rabbit ileal loops . This activity was due to a non-dialysable, heat and acid-labile antigenic protein and was lost when culture filtrates and crude enterotoxin preparations were heated at 60 degrees C for 20 min . or 56 degrees C for 30 min . respectively . Maximum activity was observed at pH 8.0-10.0; there was a gradual loss at lower pH and activity was abolished in culture filtrates held at pH 3.0 and crude enterotoxin preparations held at pH 4.0 . Titration of the crude enterotoxin preparations in rabbit ileal loops showed that the ED50 (equivalent to 1 unit of toxin) was contained in 25 microgram of protein; a logarithmic plot of the neutralisation coefficients against antiserum concentrations showed that one unit of antitoxin was contained in 42 x 10(-4) ml of the antiserum. J Clin Microbiol, 1979 Jul, 10(1), 46 - 9 Aeromonas primary wound infection of a diver in polluted waters; Joseph SW et al.; Two separate species of Aeromonas, A . sobria (not listed as a species in Bergey's Manual of Determinative Bacteriology, 8th ed.) and A . hydrophila, were primary pathogens isolated from the leg wound of a diver conducting operations in polluted waters . This is the first recorded instance of a primary infection of soft tissue in a human caused by two species of Aeromonas, one of which was resistant to tetracycline . Because of the very rapid development of this wound infection, cytotoxicity of these organisms was examined in several biological systems . A . sobria was hemolytic for sheep erythrocytes, cytotoxic for Y-1 adrenal cells, and enterotoxic in rabbit ligated intestinal loops, whereas A . hydrophila was hemolytic and cytotoxic . Pertinent clinical, bacteriological, and environmental features of the case are presented. Appl Environ Microbiol, 1979 Jul, 38(1), 108 - 13 Membrane filter procedure for enumeration of Aeromonas hydrophila in fresh waters; Rippey SR et al.; A membrane filter method (mA) for the enumeration of Aeromonas hydrophila in natural water samples was developed . The complex, primary medium employs trehalose as a fermentable carbohydrate and ampicillin and ethanol as selective inhibitors . After 20 h of incubation at 37 degrees C, an in situ mannitol fermentation test followed by an in situ oxidase test is used to further differentiate A . hydrophila from other aquatic and terrestrial microorganisms present in freshwaters . The primary medium decreases background microbial growth by about two orders of magnitude . The recoveries on mA medium from suspensions of A . hydrophila prepared from pure cultures and held for 24 h at 15 degrees C exceeded 95% of the recoveries on brain-heart infusion agar spread plates . The confirmation rate for colonies designated A . hydrophila was 98%, whereas 11% of the presumptively negative colonies were, in fact, A . hydrophila . Recoveries of A . hydrophila from fresh, surface water samples exceeded recoveries by the other methods examined. Can J Microbiol, 1979 May, 25(5), 579 - 86 Deoxyribonucleic acid relationships among members of the genus Aeromonas; MacInnes JI et al.; Polynucleotide sequences among 24 motile and 11 non-motile aeromonads were studied by analysis of deoxyribonucleic acid - deoxyribonucleic acid (DNA-DNA) duplexes with endonuclease S1 . In addition, DNA base composition (mole % guanine and cytosine (G + C)) and relative genome sizes were determined for selected strains . Large variations in genome size were found and % GC ranged from 57.1 to 62.9% . On the basis of the strains examined, the Genus Aeromonas consists of two genotypically legitimate groups: a diverse group of motile aeromonads, and the genetically more homogeneous non-motile aeromonads, comprising the species Aeromonas salmonicida . Internal homology groups could not be demonstrated within the motile aeromonads, and significant divergence in related sequences was indicated . This diverse motile group forms the single species Aeromonas hydrophila. Can Med Assoc J, 1979 Apr 21, 120(8), 942 - 6 Clinical involvement of Aeromonas hydrophila; Trust TJ et al.; Aeromonas hydrophila has for some time been regarded as an opportunistic pathogen in hosts with impaired local or general defence mechanisms . Infections in such individuals are generally severe . The organism is also being isolated with increasing frequency throughout the world from a variety of focal and systemic infections of varying severity in persons that are apparently immunologically normal . Most commonly it causes acute diarrheal disease by producing an enterotoxin . Thus the organism appears to have greater clinical significance that was hitherto suspected . The organism has been infrequently reported from humans in Canada, but its correct laboratory identification, together with increased awareness that it can contribute to illness, will undoubtedly lead to more reports of its isolation in Canada. J Wildl Dis, 1979 Apr, 15(2), 239 - 43 Isolation of Aeromonas hydrophila from the American alligator, Alligator mississippiensis; Gorden RW et al.; Aeromonas hydrophila was isolated from the internal organs of nine adult alligators, Alligator mississippiensis, which died without apparent cause, suggesting the bacterium may have been a factor . One hundred and twenty-three alligators ranging in age from six months to over 10 years were captured from five locations in the southeastern United States and sampled for A . hydrophila . The bacterium was isolated from the oral cavity of 85% of the animals, on the external jaw area from over 50% and from 70% of the internal tissue samples . A . hydrophila is ubiquitous with alligators in their natural habitats, but apparently does not cause clinical disease . However, stress factors such as trapping, handling, and warm water temperatures may be conducive to the rapid proliferation of the bacteria, thereby facilitating disease. J Clin Microbiol, 1979 Feb, 9(2), 244 - 7 Incidence of "oxidase-variable" strains of Aeromonas hydrophila; Overman TL et al.; Certain strains of Aeromonas hydrophila are oxidase negative when grown on gram-negative selective and differential media . Of 100 strains of A . hydrophila examined, 8 were found to possess this characteristic . Information is provided on how to detect these common variants of A . hydrophila. Ann Rech Vet, 1979, 10(1), 33 - 40 Furunculosis of salmonids: vaccination attempts in rainbow trout (Salmo gairdneri) by formalin-killed germs; Michel C; Two immunization trials were performed in rainbow trout, using a formalin killed Aeromonas salmonicida suspension . In the first experiment, 200 g fish were administered orally or intraperitoneally . Circulating antibodies were elicited in injected animals only, but no protection was found when they were challenged with a highly virulent strain . Rough and smooth bacteria have provided similar agglutinins titers . In the second study, fingerlings were vaccinated by injection, but experimental disease was reproduced through IP or IM inoculations . Protection was effective in the second case . In the IP injected group the mortality was the same in vaccinated fish and controls, and carriers were detected among survivors 3 months later . The surprising fact is that serum agglutinins did not always provide a protection . This last one depends on different factors such as pathogenicity of strains and route of penetration of the challenge bacteria . So, experimental challenge has to be improved. Zentralbl Bakteriol {Orig A}, 1978 Dec, 242(4), 487 - 99 Enterotoxicity of Aeromonas hydrophila: skin responses and in vivo neutralisation; Dubey RS et al.; Culture filtrates and partially purified enterotoxins of 6 strains of Aeromonas hydrophila isolated from faeces of diarrhoeic and healthy persons, drinking water, sewage and faeces of domestic animals caused induration and increased capillary permeability in skin of adult albino rabbits . The activities were less in crude enterotoxins indicating partial loss during purification . Heat treatment for 30 min at 60 degrees C and 56 degrees C inactivated the induration and permeability effects of culture filtrates and crude enterotoxins respectively . The activities were most pronounced at pH 8.0 showing gradual loss of activities at lower pH values disappearing completely in culture filtrates at 3.0 and in crude toxins at 4.0 . The induration and permeability factor activities of crude enterotoxin were neutralised proportionally in vivo with antitoxin raised against the same in rabbits . Suppression effect was more when antitoxin was injected prior to inoculation of toxin . This study demonstrates that the assay of the activity of skin permeability factor being an easier process than loop test, may be used for assay of enterotoxin of A . hydrophila. Appl Environ Microbiol, 1978 Nov, 36(5), 731 - 8 Prevalence and distribution of Aeromonas hydrophila in the United States; Hazen TC et al.; The abundance of Aeromonas hydrophila was measured in 147 natural aquatic habitats in 30 states and Puerto Rico . Viable cell counts were used to estimate density at all sites by using Rimler-Shotts medium, a differential presumptive medium for A . hydrophila . Temperature, pH, conductivity, salinity, and turbidity were measured simultaneously with water sample collection . The density of A . hydrophila was higher in lotic than in lentic systems . Saline systems had higher densities of A . hydrophila than did freshwater systems . A . hydrophila could not be isolated from extremely saline, thermal, or polluted waters, even though it was found over wide ranges of salinity, conductivity, temperature, pH, and turbidity . Of the water quality parameters measured, only conductivity was significantly regressed with density of A . hydrophila. Am J Vet Res, 1978 Aug, 39(8), 1384 - 6 Comparison of selected diagnostic tests for detection of motile Aeromonas septicemia in fish; Eurell TE et al.; Cultural isolation, slide agglutination (SA), tube agglutination (TA), microagglutination (MA), and fluorescent antibody (FA) techniqes were compared as methods for detecting motile aeromonas septicemia in channel catfish (Ictalurus punctatus) . Tests were conducted on naturally infected fish from feral populations and commercial sources, as well as on fish which were experimentally infected with a virulent culture of Aeromonas hydrophila . Increased levels of specific serum agglutinins to A hydrophila were demonstrable only in fish from whose blood the organism could be recovered . It was concluded that the SA procedure was an effective diagnostic test which would be most useful under field conditions . Under laboratory conditions, the TA, MA, and FA procedures were found to be equally effective in detecting the level of serum agglutinins to A hydrophila . The FA procedure, however, was more sensitive than any of the agglutination procedures and could be performed in less time than TA or MA. J Bacteriol, 1978 Aug, 135(2), 402 - 7 Presence of glycerophospholipid: cholesterol acyltransferase and phospholipase in culture supernatant of Aeromonas hydrophila; MacIntyre S et al.; Human erythrocyte membrane glycerophospholipids are deacylated by Aeromonas hydrophila 13-h culture supernatants, resulting in the production of cholesterol ester, free fatty acid, and water-soluble phosphates . This activity appears to be due to the actions of an acyltransferase (phosphatide:cholesterol acyltransferase, EC 2.3.1 group) and a phospholipase (phosphatide acyl-hydrolase) . The enzyme activities are produced simultaneously in late exponential/early stationary phase, are precipitated together from the culture supernatant with 85% ammonium sulfate, and are eluted together near the void volume during gel filtration on Sepharose 6B . These results suggest that A . hydrophila produces a multienzyme complex with an unusual mode of action on membrane lipids . The complex is distinct from the hemolytic factor aerolysin, which is also produced by A . hydrophila. J Protozool, 1978 Aug, 25(3 Pt 2), 351 - 5 Ultrastruct of red-sore lesions on largemouth bass (Micropterus salmoides): associattion of the ciliate Epistylis sp . and the bacterium Aeromonas hydrophila; Hazen TC et al.; Epizootic outbreaks of red-sore disease in several reservoirs in the southeastern United States have been reported to cause heavy mortality among several species of fish having sport and commercial value . The etiologic agent is said to be the peritrich ciliate Epistylis sp.; secondary infection by the gram-negative bacterium Aeromonas hydrophila produces hemorrhagic septicemia which results in death . However, in recent studies on the largemouth bass Micropterus salmoides, Epistylis sp . could be isolated from only 35% of 114 lesions from 114 fish, while A . hydrophila was found in 96% of the same lesions . Transmission and scanning electron microscopy of lesions associated with red-sore disease indicate that neither the stalk nor the attachment structure of Epistylis sp . have organelles capable of producing lytic enzymes . Since other investigators have shown that A . hydrophila produces strong lytic toxins, and in absence of evidence to the contrary, it is concluded that Epistylis sp . is a benign ectocommensal and that A . hydrophila is the primary etiologic agent of red-sore disease. Can J Microbiol, 1978 Jul, 24(7), 864 - 8 Lipopolysaccharides of the motile aeromonads; core oligosaccharide analysis as an aid to taxonomic classification; Shaw DH et al.; Twelve motile Aeromonas strains have been examined with respect to the hexose and heptose monosaccharide residures present in the core region of their cell wall lipopolysaccharides . These strains were divided into three distinctly separate groups on the basis of the various combinations of hexose and heptose residues . The assignment of a strain to any one of the three groups furnishes a distribution which is substantially the same as that recently reported in a computerbased numerical analysis . All strains tested which were previoulsy named A . liquefaciens fall into the same group. Ann Microbiol (Paris), 1978 Jul, 129B(1), 19 - 26 {Occurrence of R plasmids belonging to incompatibility group incC in Aeromonas hydrophila strains isolated from sewage water (author's transl)}; Mizon FM et al.; The susceptibility to antimicrobial agents of 321 strains of Aeromonas hydrophila was studied: 319 strains were found to be resistant to one or several antibiotics . Transfer of resistance markers was obtained from 24 strains . Five plasmids from these strains were classified into incompatibility group incC . Epidemiological consequences of R plasmid diffusion in water bacteria are discussed. J Bacteriol, 1978 Jul, 135(1), 281 - 2 Immunochemical comparison between an oxacillin-hydrolyzing penicillinase of Aeromonas hydrophila and those mediated by R plasmids; Sawai T et al.; Antiserum against an oxacillin-hydrolyzing penicillinase of Aeromonas hydrophila did not show immunochemical cross-reaction with four oxacillin-hydrolyzing penicillinases mediated by R plasmids. South Med J, 1978 Jun, 71(6), 739 - 41 Fatal Aeromonas hydrophila infection of the skin; Fulghum DD et al.; A 62-year-old woman developed a fatal Aeromonas hydrophila infection of the skin after dropping a crab trap on her leg . The area surrounding the punctures was erythematous and had several flaccid bullae . A biopsy specimen of the involved skin showed necrosis and suppuration in the dermis and subcutaneous fat . The A hydrophila sepsis resolved after treatment with gentamicin, but the patient developed secondary wound infections and died three months after injury. Medicine (Baltimore), 1978 May, 57(3), 267 - 77 Human aeromonas infections: a review of the literature and a case report of endocarditis; Davis WA 2nd et al.; Our patient, with cirrhosis and chronic renal failure, represents an example of the susceptibility of a compromised host to Aeromonas infections . This patient, however, differs from previously reported cases in at least two important aspects . First, it is possible that her portal of entry was a fresh A-V fistula puncture site rather than an intestinal site . The temporal relationship of exposure to flood water prior to the onset of sepsis lends support to this possibility . Epidemiologic investigation of the dialysis center failed to reveal Aeromonas isolates from cultures of the water supply, machinery, or other patients . Second, this case is unique in that our patient developed a destructive aortic valve endocarditis resulting in valvular perforations and acute aortic insufficiency . Furthermore, this infection was initiated on what appears to have been a previously normal valve . Based on a review of the literature and the virulence demonstrated by A . hydrophila in our patient, we conclude that organisms of the genus Aeromonas are capable of inducing serious human infection . Such infections are more likely to occur in compromised hosts . A . hydrophila has accounted for the majority of reported infections. Br J Exp Pathol, 1978 Feb, 59(1), 76 - 84 Effects of fever on host defense mechanisms after infection in the lizard Dipsosaurus dorsalis; Bernheim HA et al.; Fever has never been proven beneficial in mammals, although it enhances survival in the lizard D . dorsalis infected with Aeromonas hydrophila . We examined the course of the infection and the function of host defence in febrile (41 degrees) and afebrile (35 degrees or 38 degrees) animals using this model . Infected, febrile lizards had sterile blood cultures, and 1-2 logs fewer bacteria in body tissues 6-12 h after infection . Granulocytes appeared early and in large numbers at the site of inoculation in febrile, but not afebrile, animals . We were unable to demonstrate effects of this small range of temperatures on in vitro growth rates of bacteria, on lizard granulocyte chemotactic or phagocytic functions, or upon serum antibody levels . Our results suggest that fever enhances some aspect of the early inflammatory response, leading to increased leucocyte emigration at the local site and containment of the infection. JAMA, 1978 Jan 9, 239(2), 128 - 9 Aeromonas hydrophila sepsis in a patient undergoing hemodialysis therapy; Ramsay AM et al.; Aeromonas hydrophila septicemia complicated by a generalized cutaneous vasculitis developed in a patient receiving home hemodialysis therapy . Because the Aeromonas organism is found in many natural water sources, the possibility that this patient's hemodialysis system became contaminated was explored . Although cultures from the patient's home environment showed no Aeromonas sp, the possibility still exists that the site of contamination was in the dialysis system. Microbios, 1978, 23(92), 87 - 92 Effect of arginine analogues on a fish pathogen, Aeromonas salmonicida; Shieh HS; The effects of arginine analogues on a fish pathogen, Aeromonas salmonicida, were investigated . This organism proved to be resistant in various degrees to most arginine analogues tested but was found to be sensitive to arginine hydroxamate . Inhibition of growth by arginine hydroxamate was reversed by the addition of arginine to the bacterial culture . Incorporation of 14C from 14C-amino acids, namely, guanidoarginine, glutamate, asparate, alanine, isoleucine, serine, methyl-methionine, and cystine was affected. Am J Ophthalmol, 1978 Jan, 85(1), 114 - 7 Aeromonas hydrophila corneal ulcer; Feaster FT et al.; Two healthy men developed acute corneal ulcers caused by Aeromonas hydrophila after receiving traumatic foreign body injuries to the cornea . The ulcers resolved after treatment for gram-negative bacterial corneal ulceration . A history of contamination by water, soil, or material from an aquatic source was a significant factor in each case. Arthritis Rheum, 1977 Nov-Dec, 20(8), 1500 - 6 Septic arthritis of the glenohumeral joint . Unique clinical and radiographic features and a favorable outcome; Master R et al.; Seven patients (eight shoulders) with sepsis of the glenohumeral joint were studied clinically and radiographically . Despite the advanced age of the patients, the presence of gram-negative organisms, and multiple risk factors in each patient (including serious chronic underlying diseases), needle drainage and parenteral antibiotics were all that were required for successful management, provided early diagnosis with prompt institution of antibiotics and drainage occurred . Contrast arthrography safely guided therapy and revealed rotator cuff tears in four of six shoulders as well as frequent extra-articular extensions of the disease . A nonleukemic patient with Aeromonas hydrophilia sepsis and arthritis is reported who survived with eradication of infection and preservation of joint function . A poor prognosis for shoulder sepsis is not substantiated. Arch Intern Med, 1977 Oct, 137(10), 1461 - 4 Cholera-like diarrhea in Canada . Report of a case associated with enterotoxigenic Escherichia coli and a toxin-producing Aeromonas hydrophila; Gurwith M et al.; A 67-year-old Indian patient was admitted with an acute cholera-like illness . Toxigenic Escherichia coli producing both heat-stable and heat-labile enterotoxins grew from cultures of feces . In addition, an Aeromonas hydrophila producing a cytotoxic toxin was also isolated from this patient's feces . The unusual severity of this patient's illness may have resulted from coinfection with these two toxigenic organisms, although any role of the toxin produced by a hydrophila is speculative. Can J Microbiol, 1977 Sep, 23(9), 1161 - 4 Isolation of enterotoxigenic Aeromonas from fish; Boulanger Y et al.; This paper reports two different enterotoxigenic classes of the genus Aeromonas isolated from fishes . Strains of A . sobria were isolated from healthy fishes only wheras strains of A . hydrophila were isolated from both healthy and moribund fishes . Aeromonas sobria and hydrophilia strains produced a cytotoxic factor and were highly proteolytic . Seventy-five percent (75%) of the A . sobria strains produced only one type of hemolysis on 5% blood agar, but 92% of the A . hydrophilia produced two types of hemolysis . Enterotoxigenicity of all strains was tested by the rabbit gut loop technique and the suckling mouse test . Most of those Aeromonads were enterotoxigenic . Enterotoxigenic strains appeared to produce two different enterotoxins which were antigenically related, but they seemed to have different mechanisms of action . Enterotoxins of Aeromonas were shown to be antigenically different from those of E . coli. J Clin Microbiol, 1977 Aug, 6(2), 96 - 100 Aeromonas hydrophila in acute diarrheal disease: detection of enterotoxin and biotyping of strains; Ljungh A et al.; Eleven isolates of Aeromonas species from human stool cultures were found to produce enterotoxin activity as determined by assay of culture filtrates in rabbit intestinal loops and rabbit skin and on adrenal Y1 cells . Hemolysin(s) and a cytotoxic protein were found to interfere in all three assay systems but could be inactivated upon heating at 56 degrees C or by specific antihemolysin . Biotyping of each isolate was performed with a conventional test system and with API 50E and APIZYM kit systems (Analytab, Inc.) . No single test of the more than 70 biochemical reactions investigated was found to correlate with enterotoxigenicity in the strains of Aeromonas hydrophila examined . All strains were found to belong to ideal phenotypes of A . hydrophila, but each strain possessed its own biochemical profile. J Antibiot (Tokyo), 1977 Aug, 30(8), 649 - 54 Bacterial metabolism of anthracycline antibiotics . Steffimycinone and steffimycinol conversions; Wiley PF et al.; Streptomyces nogalater, UC-2783, and Streptomyces peucetius var . caesius, IMRU-3920/UC-5633, catalyze ketonic carbonyl reduction of steffimycinone (1, Scheme 1) . Using cell-free preparations of S . nogalater, the process of ketonic carbonyl reduction has been shown to be TPNH linked . The product, steffimycinol (2), is reduced further by Aeromonas hydrophila, 2C/UC-6303, by the process of microaerophilic conversion of anthracyclinones previously reported1,2) with the result being the formation of 7-deoxysteffimycinol (3) . The products (2 and 3) were isolated by extraction from the fermentations followed by chromatographic purification . Identification was by comparison of various physical properties and spectral data with those of authentic materials obtained by chemical means . Catalytic activity of the crude enzyme preparations of S . nogalater was lost by dialysis by restored by addition of TPNH although not by addition of DPNH demonstrating TPNH dependence . The reaction rate increased linearly with added crude enzyme protein up to 4 mg/ml and was highest between pH 6.5 and 7.0. J Clin Microbiol, 1977 May, 5(5), 514 - 6 Pathogenicity of nonpigmented cultures of Chromobacterium violaceum; Sivendra R et al.; Nonpigmented cultures of Chromobacterium violaceum have been found to be similar to pigmented cultures in their virulence for mice and the pathology of their infections . Clinicians and microbiologists should be prepared to consider nonpigmented C . violaceum in their differential diagnoses of infections caused by gram-negative bacteria . The laboratorian who is not aware of this possibility is likely to erroneously identify nonpigmented strains of C . violaceum as members of closely associated genera, particularly Aeromonas . It is known that violet pigmentation is not an essential feature or an exclusive character of the genus Chromobacterium . This study has also shown that pigmentation of C . violaceum is not related to its pathogenicity or to the pathology of its infections. J Clin Microbiol, 1977 Jan, 5(1), 112 - 3 Media-dependent oxidase reaction in a strain of Aeromonas hydrophila; McGrath VA et al.; A strain of Aeromonas hydrophila isolated from bile was oxidase positive only when grown on nonselective media . The isolate was oxidase negative when grown on gram-negative selective and/or differential media . It is proposed that oxidase tests on gram-negative rods be performed on colonies grown on nonselective media to assure valid results. Ann Biol Clin (Paris), 1977, 35(4), 329 - 37 {Study of 50 strains of Aeromonas hydrophilia isolated from fishes}; Van Impe J; A bacteriological survey of the healthy Goldfish (Carassius auratus) demonstrated the frequent occurrence of A . hydrophila . The biochemical characters and the sensitivity to 29 chemiotherapics and 15 antiseptics of 50 fish originating strains were studied and compared with a number of strains, implicated in human pathology . The results of this study indicate a good agreement for the biochemical characters and the sensitivity to chemiotherapics between the fish and the human strains . Owing to this statement, the author suggests to bear in mind the potential hazard which could result in the introduction of ornamental fishes in the hospital environment. Z Lebensm Unters Forsch, 1977, 163(1), 44 - 7 {Taxonomic studies on aeromonads of milk, water and minced meat (author's transl)}; Kleeberger A; 365 aeromonads isolated from milk, water and minced meat were tested in 24 biochemical characters . By application of a numerical method the material was devided into two subgroups . The properties of these subgroups are not in accordance with the definitions of species and subspecies of the taxonomical system of Aeromonas as it is accepted at present . With regard to the priority of the name A . punctata it is suggested to make use of only this name till the real combinations of characters and the resulting arrangement of groups are cleared to a better degree. Appl Environ Microbiol, 1976 Nov, 32(5), 723 - 5 Ultrastructural examination of Aeromonas cultured in the presence of organic lead; Silverberg BA et al.; Aeromonas sp . will methylate trimethyl lead acetate (Me3PbOAc) to volatile tetramethyl lead (Me4Pb) . Examination of cultures grown in the presence of Me3PbOAc revealed no major irregularities between cells of the treated and untreated cultures . Some cells, however, showed evidence that intracytoplasmic materials had been leached from the cells . The lead-treated cells were interpreted to contain lead ions on the basis of energy-dispersive X-ray analysis. Science, 1976 Jul 16, 193(4249), 237 - 9 Fever: effect of drug-induced antipyresis on survival; Bernheim HA et al.; To determine whether the prevention of fever affects the survival of an animal infected with pathogenic bacteria, lizards (Dipsosaurus dorsalis) were infected with live Aeromonas hydrophila and received varying doses of sodium salicylate, an antipyretic drug . Twelve lizards received identical injections of bacteria along with a nontoxic dose of sodium salicylate; five animals increased their mean body temperature at least 0.6 degrees C and survived the week, whereas seven did not develop a fever and died within 3 days . These data indicate that in these lizards the prevention of fever by use of an antipyretic drug such as sodium salicylate increases the mortality rate from bacterial infection. Am J Physiol, 1976 Jul, 231(1), 198 - 203 Fever and antipyresis in the lizard Dipsosaurus dorsalis; Bernheim HA et al.; Lizards (Dipsosaurus dorsalis) were placed in a desertlike environment in which the ambient temperature (Ta) at night (1800-0600 h) was 12 degrees C and the day (0600-1800 h) Ta was between 30 and 55 degrees C depending on the location within the chamber . When dead Aeromonas hydrophila (4 X 10(9) organisms) was injected into nine lizards, an elevation in body temperature (Tb) of 2.7 degrees C was observed during the same day . On the day after bacterial injection the lizards' body temperatures averaged 41.6 degrees C, an increase of 4.2 degrees C over their control day Tb . Further investigations on the febrile response of D . dorsalis were conducted at the University of Wisconsin's Biotron, where there exists a simulated desert environment with the light intensity, temperature, and humidity closely parelleling a typical spring day in the southwestern desert of the United States (the natural habitat of Dipsosaurus) . In this environment injection of dead bacteria into seven lizards led to an average febrile response of similar magnitude (Tb = 40.5 degrees C) but with a longer latency than that found at the University of Michigan . Injection of 13 lizards with live A . hydrophila (5 X 10(9) organism subcut.) in the simulated desert at Michigan led to a daytime fever averaging 2.3 degrees C (mean Tb = 40.6 degrees C) over a 5-day period . During the 6th and 7th day the lizards' body temperature returned to the normal or afebrile level . Injections of sodium salicylate along with dead A . hydrophila resulted in a dose-dependent attenuation of the febrile response . These results demonstrate that the reptilian febrile response is strikingly similar to avian and mammalian fever and suggest a common origin and perhaps function for the febrile mechanism. J Gen Microbiol, 1976 May, 94(1), 11 - 22 A taxonomic study of the Aeromonas hydrophila-Aeromonas punctata group; Popoff M et al.; A total of 203 characters has been determined for 68 strains of Aeromonas belonging to the Aeromonas hydrophila-A . punctata group . The results have been subjected to computer analysis using the coefficient of Jaccard-Sneath and the strains clustered by the method of aggregation according to the variance . The 68 strains can be divided into two well-segregated classes on the basis of 59 variable characters, of which seven are of diagnostic value . The two classes are considered as two separate species . The first one (42 strains) is assigned to the type species of the genus, A . hydrophila, and it appears that the species name, A . punctata, is an illegitimate synonym for A . hydrophila . The second (26 strains) constitutes a new species for which the name A . sobria sp . nov . is proposed . The type strain of this new species has been deposited under the reference CIP7433 (our strain 208). Acta Pathol Microbiol Scand {B}, 1976 Apr, 84(2), 112 - 4 Enterotoxin, haemolysin and cytotoxic protein in Aeromonas hydrophila from human infections; Wadstrom T et al.; Three different toxins were detected in culture supernatants from 11 strains of Aeromonas hydrophila . The haemolysin and the cytotoxic factor(s) interferred in the three test systems for enterotoxin, but they could be neutralized by heating at 56 degrees C or by specific antihaemolysin. J Wildl Dis, 1976 Apr, 12(2), 247 - 53 Necrosis and bacterial infection in channel catfish (Ictalurus punctatus) following hypoxia; Plumb JA et al.; Apparently sterile lesions developed in the skin and musculature of channel catfish (Ictalurus punctatus) six days after fish were severely stressed by an oxygen depletion associated with a phytoplankton die-off in an 8.9 ha pond . Lesions were characterized by hemorrhage and necrosis . Aeromonas hydrophila was isolated from either the lesions ot internal organs of all moribund fish necropsied the day after lesions were first found . As the water quality improved the health of the fish improved . Water quality data collected before and after the oxygen depletion, and associated fish mortality, are presented. Arthritis Rheum, 1976 Mar-Apr, 19(2), 169 - 72 Acute arthritis caused by Aeromonas hydrophola: clinical and therapeutic aspects; Chmel H et al.; Two cases of Aeromonas hydrophila arthritis are reported and a third case present in the literature is reviewed . All three cases occurred in patients with myelogenous leukemia; the knee joint was involved in 2 patients and the metacarpal-phalangeal joint in the third . In the 2 patients presented here, synovial fluid antibiotic levels were measured and were adequate; but A hydrophila was repeatedly cultured from the knee joints, a fact suggesting that other factors, such as normal functioning leukocytes and specific opsonizing antibody against the organism, are also necessary to kill A hydrophila. Ann Sclavo, 1976 Mar-Apr, 18(2), 322 - 37 {Immunofluorescence technique applied at serological diagnosis of the respiratory tract infections from gram-negatives bacteria (author's transl)}; Visconti A; The immunofluorescence indirect technique was evaluated for detecting specificities, Ig classes, and levels of serum and sputum antibodies against bacteria isolated from sputa in patients with broncho-pulmonary infections . Results obtained with the FA method were compared with those obtained with a passive haemagglutination test . The former method gave much more reliable results than the latter . By using FA indirect method it was possible to assess pathogenicity of baceterial strains isolated from sputum and to establish their ethiological significance in many clinical cases whose sputum cultures were impossible or difficult to evaluate, as for instance in a patient with a chronic bronchitis exacerabtion caused by a strain of Aeromonas hydrophila . Further investigation are suggested in order to improve technically the FA method and to find the easiest and most reliable way out to evaluated the effectual relationship between bacteria in sputum and immunoglobulin response in sputum or in serum of patient with respiratory tract infections due to bacteria. Zentralbl Bakteriol {Orig B}, 1976 Mar, 161(5-6), 482 - 97 {The detection of aeromonads of the "hydrophila-punctata-group" within the hygienic control of drinking water (author's transl)}; Schubert R; The first part brings a retrospective analysis of bacteriological water examinations at single wells at which within a new one year examination period E . coli, coliforms and colony count determinations were performed and in addition the water samples were examined regarding Aeromonas of the "Hydrophila-Punctata-Group" . The single wells have been divided in five groups because of the pre-testing and reexamination results and because of the local circumstances . They are summarized in the tables 1-5 . The second part reports about the findings of the examination regarding the relation of aerogenic to anaerogenic Aeromonads in wells close to the shore in the direction of infiltration . It also reports about flat wells without influence of surface water in ground-water areas with relatively porous surface layer . Whilst in river water loaded with sewage the anaerogenic Aeromonads dominate the population up to about 80% their proportion diminishes in the shore filtrate so that within a certain distance, in groundwater filtered through the shore, only aerogenic Aeromonads are found . Also, from the water of flat wells with relatively porous surface layer exclusively aerogenic Aeromonads colonies have been isolated . Proceeding from these results the findings of the single wells divided in the groups 1-5 have been discussed . Because the aerogenic Aeromonads have not been found in deep wells but more or less frequently in flat wells the proof of anaerogenic Aeromonas obviously demonstrates a pollution of surface water loaded with sewage. J Clin Microbiol, 1976 Feb, 3(2), 102 - 4 Meningitis due to Aeromonas hydrophila; Qadri SM et al.; A case of meningitis caused by Aeromonas hydrophila is reported . The infection complicated an otherwise successful frontotemporal craniotomy . Survey of the literature revealed that human infections due to this organism are relatively uncommon, and its causal relationship in meningitis has not been previously reported . A . hydrophila is known to cause bacteremia in patients under treatment with immunosuppresive agents . We report meningitis with bacteremia, caused by this organism, in an immunologically competent host. Appl Environ Microbiol, 1976 Feb, 31(2), 216 - 20 Starvation effects on Escherichia coli and aquatic bacterial responses to nutrient addition and secondary warming stresses; Wu SY et al.; A gram-negative polar flagellated rod, isolated from a Colorado mountain stream and considered to be an Aeromonas sp., a mixed aquatic microbial population, and a culture of Escherichia coli were starved to determine their responses to the short-term presence of nutrients and mild warming stress (49.5 C for 2 min) in relation to starvation time . At the beginning of the starvation period, the Aeromonas isolate was extremely sensitive to the secondary warming stress . This response was markedly diminished after a 3-week starvation period . The mixed aquatic microbial population showed a similar trend in becoming less sensitive to stress with increased starvation . E coli under similar conditions, became more sensitive to the secondary stress after exposure to glucose . Respiration measurements after glucose additions also indicated that E . coli responded in a different manner to starvation stress and glucose presence than the Aeromonas isolate . The increased sensitivity of E . coli to secondary stress and short-term nutrient availability after starvation may contribute to the exclusion of this organism from aquatic environments. J Wildl Dis, 1976 Jan, 12(1), 77 - 82 Blood changes in brook trout induced by infection with Aeromonas salmonicida; Shieh HS et al.; Furunculosis was induced in brook trout, Salvelinus fontinalis, by experimental inoculation with Aeromonas salmonicida . Total protein, hemoglobin, sialic acid, fatty acids, triglycerides, cholesterol, inorganic-phosphorus, acid-soluble phosphorus, and lipid-phosphorus decreased in the blood of the infected fish while amino acids, urea, total creatinine, ammonia, and glucose increased . Pyruvic acid, lactic acid, and ascorbic acid values showed no significant change. Ann Rech Vet, 1976, 7(4), 307 - 13 {Production of anti-Aeromonas salmonicida agglutinins by the rainbow trout . Influence of temperature, an adjuvant and an immunosuppressive agent}; Maisse G et al.; Adult rainbow trout were immunized intraperitoneally with a chloroform killed Aeromonas salmonicida suspension . Agglutinating antibodies were titrated using a microtiter system . Antibody activity was associated with IgM fraction obtained from Sepharose 4 B gel filtration . The kinetics of antibody formation were established at three temperatures . At 50C detectable antibodies were found at day 50 post immunization . At 10degrees C and 16 degrees C the agglutinin titer rose before day 20 . The antibody titer was significantly raised by Freund's complete adjuvant, but cyclophosphamide at a total dose of 500 mg/kg of body weight administered in 10 injections before and after immunization had no effect. Zentralbl Bakteriol {Orig A}, 1975 Nov, 233(3), 437 - 354 {Demonstration of specific antibodies in sera of patients with infections caused by aeromonas hydrophila (author's transl)}; Caselitz FH et al.; According to the formation of specific antibodies against Aeromonas hydrophilia in patients with infections caused by this microorganism the sera of two patients of different clinical picture were investigated . Among the antibodies there could be demonstrated the antihaemolysins against the haemolysin of the monolgous strain, agglutinins against the O-antigen and praecipitins against soluble antigens . The special problems of the technics are described . The results are discussed and interpreted. J Wildl Dis, 1975 Oct, 11(4), 489 - 93 Fish furunculosis caused by Aeromonas salmonicida var . achromogenes; McCarthy DH; An epizootic of sub-acute furunculosis caused by an acromogenic variety of Aeromonas salmonicida is described . Bacteriologic, serologic and virulence characteristics of the isolate are presented. Zentralbl Bakteriol {Orig A}, 1975 Oct, 233(2), 232 - 5 {Aeromonas punctata subsp . caviae as the causative agent of acute gastroenteritis (author's transl)}; Fritsche D et al.; Since in the past, Aeromonas hydrophila had been isolated from all cases of human infection described . A . punctata and the anaerogenic sub-species were considered as apathogenic . From the case described, a close association between acute diarrhea with vomiting and the identification of A . punctata subsp . caviae becomes evident so that a conditional pathogenicity of this sub-species must be assumed . The question is discussed whether a preceding disturbance of the intestinal habitat in the presence of a particular susceptibility of the gastrointestinal tract promoted gastro-enteritis . Infection may have been brought about by the ingestion of surface water contaminated by sewage . Attention is again drawn to the fact that in the case of enteritis occuring during the open-air bathing season, faeces samples should also be examined for their Aeromonas content which may be performed by a simple indophenol or so-called cytochrome oxidase reaction of the aerobic flora in feces by rubbing off colonies into a corresponding test strip. Zentralbl Bakteriol {Orig B}, 1975 May, 160(3), 237 - 45 {The relation of aerogenic to anaerogenic aeromonads of the "Hydrophila-Punctata-group" in river water depending on the load of waste (author's transl)}; Schubert RH; The analysis of the relation of the aerogenic and anaerogenic Aeromonas-Species of the "Hydrophila-Punctata-Group" in moving waters of a varying load of waste demonstrates that in the sewage water the anaerogenic subspecies A.hydrophila subsp . anaerogenes and A.punctata subsp . caviae predominate over the aerogenic species A.hydrophila and A.punctata with an average of 78% . Polysaprobic rivers and brooks show a similar relation . To the contrary, the aerogenic Aeromonads-mainly A.hydrophila-dominate over the anaerogenic Aeromonads in oligosaprobic brooks with a low range of variation of the individual value with 90% on the average . The alpha- and beta-mesosaprobic rivers show-with a great variation of the values indicated at each test place-a relation of aerogenic to anaerogenic Aeromonads of 39:61 for the alpha-mesosaprobics and 43:57 for the beta-mesosaprobics on an average; consequently, they are close to each other in average analysis . The great differences in the individual value of both groups seem, however, to make it possible that the determination of the relation of the aerogenic Aeromonads to the anerogenic could show a more sensitive system of waste contamination or of waste load than the saprobic system used in comparison . Since the anaerogenic subspecies A.hydrophila subsp . anerogenes and A.punctata subsp . caviae are very similar to each other from the ecological point of view and A.hydrophila of the aerogenic species is the widely predominating microorganism it seems to be sufficient for practical purpose to determine the relation of aerogenic to anaerogenic Aeromonads of the "Hydrophila-Punctata-Group"; a further differentiation does not assist in obtaining more information at the present time. Science, 1975 Apr 11, 188(4184), 166 - 8 Fever and survival; Kluger MJ et al.; The significance of fever in response to a bacterial infection has been investigated using the lizard Dipsosaurus dorsalis as an animal model . These lizards develop a fever of about 2 degrees C after injection with the bacterium Aeromonas hydrophila . To determine whether this elevation in body temperature increases the resistance of the host to this infection, as measured by survival, lizards were infected with the live bacteria and placed in a neutral (38 degrees C), low (34 degrees or 36 degrees C), or high (40 degrees or 42 degrees C) ambient temperature . An elevation in temperature following experimental bacterial infection results in a significant increase in host survival. Med Microbiol Immunol (Berl), 1975, 161(2), 79 - 87 Characterization of three Aeromonas and nine pseudomonas species by extracellular enzymes and haemolysins; Nord CE et al.; Strains from type culture collections and clinical isolates belonging to the Aeromonas and Pseudomonas genera were identified with conventional tests . Production of extra-cellular enzymes and haemolysins were detected by simple plate agar methods . The following enzymes were found to be of special value for a rapid and simple classification of certain species in both genera: potease (casein and gelatin agar), lecithinase (lecithin agar), and deoxyribonuclease (DNA agar) . Elastase, staphylolytic enzyme, lipase, ribonuclease, amylase, and egg yolk reaction were other enzymes studied . However, these tests were not positive for more than 90% of any species . A . hydrophila, A . salmonicida, and P . aeruginosa were haemolytic on agar containing rabbit erythrocytes.
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