Curr Opin Genet Dev, 1992 Dec, 2(6), 937 - 42 Population genetics of microbial organisms; Hartl DL; Population data suggest that many parasitic protozoa (e.g . Trypanosoma, Leishmania, Entamoeba and Giardia) reproduce clonally, but this hypothesis has been highly controversial for Plasmodium falciparum . Although reproduction is predominantly clonal in the enteric bacteria Escherichia coli and Salmonella, the level of recombination affecting short (< 1 kb) regions of the chromosome is sufficient such that many genes are obviously mosaics of different ancestries . Transposable insertion sequences in E . coli are examples of selfish DNA whose short-term population dynamics are determined mainly by transposition and horizontal transmission among strains balanced against the regulation of transposition as a function of copy number, and negative effects on fitness . Occasional advantageous effects of transposable elements have also been documented. Afr J Med Med Sci, 1992 Dec, 21(2), 83 - 7 Influence of four Nigerian food additives on the mutagenicity of aflatoxin B1; Osowole OA et al.; The mutagenicity of aqueous extracts of four Nigerian food additives namely Xylopia aethiopica (Xa), Monodora species (Ms); fermented Litrillus lanatus-ogiri (Og) and fermented Parikia africans (African locust bean)-Iru (Ir) alone and in combination with different concentrations of aflatoxin B1 (0.05 microgram-0.25 micrograms) in the presence and absence of fecalase was studied using the Ames' salmonella mutagenicity assay system . Preliminary screening tests show the tester strain TA98 to be the most sensitive of the four tester strains (TA97, TA98, TA100, TA102) screened . The most mutagenic of the doses of the extracts are 3mg each of Xa and Ms per plate and 5mg each of Og and Ir per plate . A combination of these doses with different concentrations of aflatoxin B1 resulted in an enhanced mutagenicity of aflatoxin B1 . The increases could not be accounted for by additive mutagenicity of the extracts and aflatoxin B1 . Fecalase further increased the effects resulting from these combinations with the exception of Xa which showed a decrease in mutagenic induction . The increase may be indicative of the presence of some mutagenic glycosides in the extracts. Malays J Pathol, 1992 Dec, 14(2), 69 - 76 In situ hybridisation: principles and applications; Looi LM et al.; In situ hybridisation (ISH) is based on the complementary pairing of labelled DNA or RNA probes with normal or abnormal nucleic acid sequences in intact chromosomes, cells or tissue sections . Compared with other molecular biology techniques applicable to anatomical pathology, ISH enjoys better rapport with histopathologists because of its similarity to immunohistochemistry . It has the unique advantage over other molecular biology techniques--largely based on probe hybridisation with nucleic acid extracted from homogenised tissue samples--of allowing localisation and visualisation of target nucleic acid sequences within morphologically identifiable cells or cellular structures . Probes for ISH may bear radioactive or non-radioactive labels . Isotopic probes (3H, 32P, 35S, 125I) are generally more sensitive than non-isotopic ones but are less stable, require longer processing times and stringent disposal methods . Numerous non-isotopic labels have been used; of these biotin and digoxigenin are the reporters of choice . Optimised non-isotopic systems of equivalent sensitivity to those which use radioactive-labelled probes have been described . In ISH, finding the optimal balance between good morphological preservation of cells and strong hybridisation signals is crucial . Tissue fixation and retention of cytoskeletal structures, unfortunately, impede diffusion of probes into tissues . ISH sensitivity is also influenced by inherent properties of the probe and hybridisation conditions . Although ISH is largely a research tool, it is already making strong inroads into diagnostic histopathology . It has been applied for the detection of various infective agents particularly CMV, HPV, HIV, JC virus, B19 parvovirus, HSV-1, EBV, HBV, hepatitis delta virus, Chlamydia trachomatis, salmonella and mycoplasma in tissue sections.(ABSTRACT TRUNCATED AT 250 WORDS) Yakugaku Zasshi, 1992 Dec, 112(12), 934 - 9 {Antimutagenic substances in the Armeniacae semen and Persicae semen}; Yamamoto K et al.; Using the Ames/Salmonella/microsome assay, we examined the antimutagenic effect of the hexane extract of Armeniacae semen (apricot (Prunus armeniaca L.) seed), Persicae semen (peach (P . persica Bat.) seed), and seeds of cherry (P . avium L.), plum (P . salicina Lindle) and almond (P . dulcis Mill) . Hexane extracts of Armeniacae semen and Persicae semen inhibited the mutagenicity of benzo{a}pyrene (B{a}P), but those of seeds of cherry, plum and almond did not . The mutagenicities of 3-amino-1,4-dimethyl-5H-pyrido{4,3-b}indole (Trp-P-1) and 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) were also inhibited by the extracts of Armeniacae semen and Persicae semen . Inhibitory substances in Persicae semen were fractionated by silica gel column chromatography and high performance liquid chromatography, and were identified as oleic acid and linoleic acid . The contents of oleic acid and linoleic acid were 0.7 and 0.4% in the hexane extract of Armeniacae semen, and 1.5 and 0.5% in that of Persicae semen, respectively. Enferm Infecc Microbiol Clin, 1992 Dec, 10(10), 597 - 601 {Molecular study of ampicillin resistance in clinical isolates of Salmonella}; Gallego L et al.; BACKGROUND: The purpose of this work was to study the molecular basis of beta-lactamase production in ampicillin-resistant strains of Salmonella spp . METHODS: It was performed analytical isoelectric focusing of beta-lactamases produced by a group of 33 strains selected in basis of their resistance phenotype . Plasmid profile analysis and assays of transferable drug resistance were developed . The study was completed by hybridization experiments with an intragenic TEM probe which allowed the location of the bla-TEM gene . RESULTS: By analytical isoelectrofocusing we found that 26 out of the 27 ampicillin-resistant strains produced beta-lactamases with pl 5.4 and/or 5.6 corresponding to TEM-1 and/or TEM-2 type . Analysis of plasmid DNA revealed in almost all strains plasmids ranging in size from 1.1 to 125 Mdal . This plasmids were responsible of the resistance and, moreover, were able to transfer the resistance by conjugation mechanisms . Southern blot analysis detected the gene that code the TEM beta-lactamase at the 125, 8 and 5.8 Mdal plasmids . CONCLUSIONS: Resistance to ampicillin in the strains of Salmonella studied was due to the presence of TEM type beta-lactamases coded by conjugative plasmids . These plasmids coded also resistance to other antimicrobial agents . Our results showed that the use of a DNA probe to the detect TEM-type beta-lactamases using a non radioactive probe, could be a suitable alternative to isoelectric focusing. Cesk Epidemiol Mikrobiol Imunol, 1992 Dec, 41(6), 342 - 5 {Phagotypes of the Salmonella paratyphi B strains isolated in Czechoslovakia 1986-1991}; Majtanova L; The author presents an account of phagotypes of 70 strains of Salmonella paratyphi B isolated in 1986-1991 incl., from patients suffering from typhus B and registered carriers, isolates from river water and also from three new cases of carriers in Czechoslovakia . These isolated strains were sent for typing of Salmonellae to a Bratislava department for phagotyping . According to lytic findings with standard bacteriophages the strains were classified into 8 types . Another group is formed by strains which cannot be typed in the critical dilution (RTD) nor in its tenfold concentration (19.1%) . During the investigation period the subtype 3aI (38.3%) and the phage type Taunton (21.9%) were most frequent. Dtsch Tierarztl Wochenschr, 1992 Dec, 99(12), 489 - 90 Effect of sample selection from experimentally contaminated hatching eggs and freshly hatched chicks on Salmonella enteritidis detection rate; Hafez HM et al.; The conventional culture methods of hatching eggs using shell and/or egg contents for detection of salmonella organisms give mostly unsatisfactory results . The aim of the present study is to evaluate selection of other samples and techniques of culturing hatching eggs and freshly hatched chicks . This current study provides the best evidence of Salmonella enteritidis in artificially contaminated eggs (Layer type) by using enrichment broth in empty egg shell samples in comparison to culturing samples from yolk, albumen or from shell above the air cell (with the outer shell membrane) . The isolation rates could be enhanced if empty egg shell was initially filled with Buffered Pepton Water as pre-enrichment broth . Examination of organs from freshly hatched chicks revealed that crop samples give mostly higher reisolation rates. Dtsch Tierarztl Wochenschr, 1992 Dec, 99(12), 483 - 5 {Immunizing against salmonella infections with live and inactivated vaccines}; Vielitz E et al.; A live attenuated auxotrophic S . typhimurium (S . tm.)-mutant was used by orally administration via drinking water several times during rearing, combined with 1- or 2-times parenteral injection of an autogenous S . enteritidis (S . e.)/S . tm.-oil emulsion vaccine . In a 8-month period, more than 500,000 birds were vaccinated . The vaccine was safe . Challenge test showed protection in the vaccinates and their offspring . The number of isolates in the farms detected by regular monitoring decreased . The protection of the live-culture mutant lasted about only 8 to 10 weeks . A . S . tm.-mutant more potent for chickens will be tested now . We consider vaccinations as one important factor in a salmonella control program, especially for commercial layers and broiler breeders. Nihon Kyobu Shikkan Gakkai Zasshi, 1992 Dec, 30 Suppl, 225 - 31 {Lipopolysaccharide binding protein enhances intratracheally administrated lipopolysaccharide-induced acute lung inflammation via a CD14 receptor}; Ishii Y et al.; We examined the role of lipopolysaccharide binding protein (LBP) in the airspace and the CD14 receptor on alveolar macrophages in TNF alpha production and neutrophil (PMN) sequestration in lungs induced by intratracheal injection of lipopolysaccharide (LPS) . LPS alone (Salmonella minnesota wild-type; 20 ng) or LPS + LBP complex {LPS (20 ng) + rabbit LBP (500 ng); preincubated for 30 min at 37 degrees C} was injected intratracheally into isolated rabbit lungs perfused with lactate-Ringer-albumin solution . Human PMN (5 x 10(7)) were added to the perfusate after 2 hr perfusion . Samples of lung perfusate were collected every 30 min for 180 min, after which bronchoalveolar lavage (BAL) was also performed . TNF alpha concentration in the perfusate and BAL fluid were determined using a bioassay with L-929 fibroblasts . PMN accumulation in the lung was determined by myeloperoxidase assay of the lung homogenate . LPS alone did not significantly increase TNF alpha production or PMN accumulation in lungs, whereas LPS/LBP complex increased TNF alpha concentration in the perfusate and PMN accumulation . Intratracheal injection of anti-CD14 antibody (40 micrograms) with LPS/LBP complex prevented TNF alpha production and subsequent PMN sequestration . We conclude that LBP in the airspace enhances the effect of LPS on TNF alpha production via a CD14-dependent pathway, and this subsequently contributes to PMN sequestration in the lungs . Airspace accumulation of LBP secondary to increased vascular and epithelial permeability may play a critical role in the development of septic shock and lung injury by promoting TNF alpha production via a CD14-dependent mechanism. Mutat Res, 1992 Dec, 298(2), 125 - 9 Mutagenic activity of the leachate of municipal solid waste landfill; Omura M et al.; Organic concentrates were recovered using XAD-2/8 resin adsorption from the leachates of municipal solid waste landfills and their mutagenic activities were tested for 8 months using the Ames Salmonella/microsome assay . Highly polluted leachates (COD and BOD > or = 40 mg/l) generally had equal or higher mutagenic activities than lightly polluted leachates (COD and BOD < 40 mg/l) . But there was no clear difference in mutagenicity per amount of concentrate between the two leachates . These results suggest that the mutagenic activity of landfill leachate is decided to some degree by the organic concentration in the leachate . The mutagenic activities detected even in lightly polluted leachates were not so low as those of various kind of surface waters ever reported . It is suggested that it is important to investigate the mutagenic activity of the leachate for evaluation of the impact of landfill leachate on the environment. Mutat Res, 1992 Dec, 298(2), 113 - 23 Urban air pollution: use of different mutagenicity assays to evaluate environmental genetic hazard; Poli P et al.; The genotoxic activities associated with airborne particulate matter collected in Parma (northern Italy) have been determined . The airborne particle extracts were tested for mutagenicity using Salmonella frameshift (TA98) and base-substitution (TA100) tester strains with and without S9 microsomal activation and Saccharomyces cerevisiae strain D7 in order to determine the frequency of mitotic gene conversion and ilv1-92 mutant reversion in cells harvested at stationary and logarithmic growth phase . The relationship between mitochondrial DNA mutations and ageing, degenerative diseases and cancer prompted us to take into account the mitochondrial informational target, i.e., the respiratory-deficient (RD) mutants . The results obtained show a variability in the response for the different test systems during different months . The Salmonella mutagenicity trend was directly correlated with carbon monoxide, nitrogen oxides (NOx) and Pb concentration in airborne particulates and inversely correlated with temperature, whereas the mitochondrial genotoxic effect was higher during spring and late summer . These data suggest that the genotoxic risk assessment is a time-dependent value strictly correlated with the evaluation system being tested. Mutat Res, 1992 Dec, 298(2), 105 - 11 Genotoxicity of heated cooking oil vapors; Qu YH et al.; Epidemiological studies of lung cancer in Chinese women indicated that factors other than cigarette smoking are related to lung cancer risk . A case-control study suggested that indoor air pollution, particularly from cooking oil emissions, may be involved . Condensates of volatile emissions from rapeseed and soybean cooking oils were prepared and found to be genotoxic in short-term tests including the Salmonella mutation assay, SV50 forward-mutation assay, and sister-chromatid exchange assay, as well as the micronucleus assay in mouse bone marrow . In contrast, condensates from rapeseed oil with butylated hydroxyanisole or hydrogenated rapeseed oil were not mutagenic, implicating oxidation products as the cause for mutagenicity . Peanut oil and lard condensates were not mutagenic in any assay . The association of exposure to Chinese rapeseed cooking-oil emissions and lung-cancer risk may be related to the mutagenic component of these condensates. J Clin Invest, 1992 Dec, 90(6), 2209 - 19 Lipopolysaccharide binding protein enhances the responsiveness of alveolar macrophages to bacterial lipopolysaccharide . Implications for cytokine production in normal and injured lungs; Martin TR et al.; A plasma lipopolysaccharide (LPS)-binding protein (LBP) has been shown to regulate the response of rabbit peritoneal macrophages and human blood monocytes to endotoxin (LPS) . We investigated whether LBP is present in lung fluids and the effects of LBP on the response of lung macrophages to LPS . Immunoreactive LBP was detectable in the lavage fluids of patients with the adult respiratory distress syndrome by immunoprecipitation followed by Western blotting, and also by specific immunoassay . In rabbits, the LBP appeared to originate outside of the lungs, inasmuch as mRNA transcripts for LBP were identified in total cellular RNA from liver, but not from lung homogenates or alveolar macrophages . Purified LBP enhanced the response of human and rabbit alveolar macrophages to both smooth form LPS (Escherichia coli O111B:4) and rough form LPS (Salmonella minnesota Re595) . In the presence of LBP and LPS, the onset of tumor necrosis factor-alpha (TNF alpha) production occurred earlier and at an LPS threshold dose that was as much as 1,000-fold lower for both types of LPS . In rabbit alveolar macrophages treated with LBP and LPS, TNF alpha mRNA appeared earlier, reached higher levels, and had a prolonged half-life as compared with LPS treatment alone . Neither LPS nor LPS and LBP affected pHi or {Cai++} in alveolar macrophages . Specific monoclonal antibodies to CD14, a receptor that binds LPS/LBP complexes, inhibited TNF alpha production by human alveolar macrophages stimulated with LPS alone or with LPS/LBP complexes, indicating the importance of CD14 in mediating the effects of LPS on alveolar macrophages . Thus, immunoreactive LBP accumulates in lung lavage fluids in patients with lung injury and enhances LPS-stimulated TNF alpha gene expression in alveolar macrophages by a pathway that depends on the CD14 receptor . LBP may play an important role in augmenting TNF alpha expression by alveolar macrophages within the lungs. Mutat Res, 1992 Dec 1, 284(1), 147 - 58 Tests for recombinagens in fungi; Zimmermann FK; Three types of mitotic recombination can be studied in Aspergillus nidulans and Saccharomyces cerevisiae: (1) The classical type of reciprocal mitotic crossing-over which can be detected when it occurs between non-sister chromatids at the four-strand stage followed by co-segregation of a crossing-over and a non-crossing-over chromatid in the subsequent mitotic division . Consequently, mitotic crossing-over reflects cellular responses to primary genetic damage in the G2 phase of the cell cycle . (2) Mitotic gene conversion is a unidirectional event of a localized transfer of genetic information between non-sister chromatids which in yeast can extend to segments of up to 18 cM and even beyond 22 cM in Aspergillus nidulans . Mitotic gene conversion can also occur between unreplicated chromatids and lead to the expression of the newly created genotype without any need for a subsequent mitotic cell division . It reflects a cellular response in G1 . (3) Mitotic sister-strand gene conversion can be studied in a recently constructed strain with the same technical ease as classical non-sister chromatid gene conversion . It can be induced by chemicals which do not induce mutation in the Salmonella system and non-sister chromatid gene conversion . Mitotic segregation in Saccharomyces cerevisiae results almost exclusively from crossing-over and gene conversion whereas mitotic chromosomal malsegregation contributes only very little . In contrast to this, in Aspergillus nidulans, both processes contribute considerably so that mitotic segregants always have to be tested for their mechanistic origin. Biochemistry, 1992 Nov 24, 31(46), 11626 - 31 Oxygen radical-mediated DNA damage by redox-active Cr(III) complexes; Sugden KD et al.; The mechanism of DNA damage induced by Cr(III) complexes is currently unknown even though it is considered to be the ultimate biologically active oxidation state of chromium . In this study, we have employed the Salmonella reversion assay to identify mutagenic Cr(III) complexes . Cyclic voltammetry was used to differentiate the redox kinetics between mutagenic and selected nonmutagenic Cr(III) species . Plasmid relaxation of supercoiled DNA was employed to show in vitro interactions with plasmid DNA and correlate the interactions with the electrochemical behavior and biological activity . The results of this study demonstrate that the mutagenic Cr(III) complexes identified in the Salmonella reversion assay display characteristics of reversibility and positive shifts of the Cr(III)/Cr(II) redox couple consistent with the ability of these Cr(III) complexes to serve as cyclical electron donors in a Fenton-like reaction . These same mutagenic complexes display an ability to relax supercoiled DNA in vitro, presumably by the induction of single-strand breaks . Nonmutagenic complexes were selected to test different ligands to determine how the ligand directs the activity of Cr(III) complexes . All nonmutagenic complexes tested thus far have shown classical irreversibility, more negative reduction potentials, and an inability to relax supercoiled plasmid DNA . These results suggest that the mechanism by which chromium complexes potentiate mutagenesis involves an oxygen radical as an active intermediate . These data also demonstrate the effect of associated ligands with regard to the ability of a metal to generate an active redox center. Mutat Res, 1992 Nov 16, 270(2), 87 - 95 Genotoxicities of nitropyrenes and their modulation by apigenin, tannic acid, ellagic acid and indole-3-carbinol in the Salmonella and CHO systems; Kuo ML et al.; Four naturally occurring compounds, indole-3-carbinol (I3C), apigenin (Api), ellagic acid (EA) and tannic acid (TA), were tested for their inhibitory effects against 1-nitropyrene- (1-NP) or 1,6-dinitropyrene (1,6-DNP)-induced genotoxicity in Salmonella tester strains and Chinese hamster ovary (CHO) cells . Api and TA strongly inhibited the bacterial mutagenesis induced by nitropyrenes, while I3C and EA had little or no effect . For example, in TA98, 0.2 mumole Api resulted in 48% and 56% inhibition of the mutagenicity induced by 4 nmole 1-NP and 0.035 nmole 1,6-DNP, respectively . With an equal dose, TA caused 46% and 50% reduction of the mutagenicity induced by 1-NP and 1,6-DNP, respectively . As expected, a good correlation was observed between the antimutagenicity of nitropyrenes and their inhibitory effect on nitroreductase activity . This indicated that one of the possible antimutagenic mechanisms of Api or TA was to inactivate the metabolism of nitropyrenes . Two biological end-points, cytotoxicity and sister-chromatid exchange (SCEs), were used to screen the antigenotoxic effects of these compounds in CHO cells . At the sub-cytotoxic dose, I3C, Api and TA all protected against the cytotoxicity induced by 1-NP and 1,6-DNP, but only TA and Api gave a significant reduction of the frequency of SCEs . Moreover, this reduction was found to be highly dose-dependent. Rev Prat, 1992 Nov 15, 42(18), 2286 - 91 {Salmonellosis: therapeutic aspects}; Guillemot D et al.; The antibiotic therapy of salmonellosis has changed during the last decade, due to the development of resistance to classical drugs and also to increased knowledge in the conditions of in vitro and in vivo efficacy of new compounds . These new informations led to clinical studies of efficacy and tolerance of fluoroquinolones in the treatment of acute diarrhea or chronic carriage due to Salmonella, or against typhoid fever . These drugs appeared very efficacious and able to significantly shorten the duration of treatment . However, two potential pitfalls have to be kept in mind deserving additional informations: selection of resistant mutants and increased risk of persistent carriage. Rev Prat, 1992 Nov 15, 42(18), 2283 - 4 {Non-typhoid salmonellosis in HIV infection}; Dellamonica P et al.; Non-typhoid Salmonella infections associated with HIV infection are 20 times more frequent than those observed in the general population . Drug addicts and homosexuals are equally infected . Concerning physiopathology, a deficit in gastric acid secretion has been blamed as an etiological factor, together with T-cell deficit, except for reduction in the number of CD4 cells . This type of infection usually presents as fever; diarrhea is noted in only 20% of the cases . Several viscera can be involved . The best treatment seems to be fluoroquinones administered during 3 weeks, and several months in case of relapse . Patients under AZT therapy are less often affected with salmonellosis due to the antibiotic activity of this anti-retrovirus agent. Rev Prat, 1992 Nov 15, 42(18), 2275 - 8 {Epidemiology of minor salmonellosis}; Bouvet E et al.; Epidemiological data concerning non Typhi salmonella infections in France and other industrialized countries are characterized by the important increase of S . enteritidis salmonellosis due to raw or insufficiently cooked eggs products since 1987, increase of salmonellosis among immunosuppressed patients, particularly patients with AIDS . There is a new interest for non typhi salmonellosis instead of typhoid fever which is regularly declining in industrialized countries. Rev Prat, 1992 Nov 15, 42(18), 2268 - 70 {Resistance of Salmonella}; Mainardi JL et al.; The emergence and the increase of antibiotic resistant Salmonella particularly in non-typhi species has occurred in recent years . Beside plasmid mediated resistance, new resistance mechanisms like alterations of permeability have been identified . Factors associated with resistance are the use of antibiotics in human and animals . These findings have important public health implications . It seems necessary to define a more adapted policy in human and veterinary use in order to avoid the rapid emergence of drug-resistance among regularly active antibiotics like fluoroquinolones. Rev Prat, 1992 Nov 15, 42(18), 2263 - 7 {Physiopathology of intestinal Salmonella infection}; Sansonetti PJ; Following a long period during which studies on the pathogenesis of salmonellosis and typhoid fever have been exclusively based on careful evaluation of clinicopathological data in infected patients and experimental infection in mice, the new tools that are now offered by molecular genetics and cell biology allow more systematic and analytical approaches . Numerous mutants have been obtained that can be assayed in selected cell assay systems such as in vitro-cultivated epithelial cells or macrophages, thus allowing to identify and characterize key virulence bacterial products as well as their eucaryotic receptors and effectors . Significant contributions have recently been made in the analysis of the mechanisms allowing invasion of the intestinal epithelium and survival and multiplication of bacteria within macrophages . However, many unsolved questions remain . It is still unclear what produces diarrhea during salmonellosis and studies on the pathogenesis of typhoid fever are still impaired by the lack of a proper animal model. J Am Vet Med Assoc, 1992 Nov 15, 201(10), 1615 - 6 Pneumonia associated with Salmonella choleraesuis infection in swine: 99 cases (1987-1990); Turk JR et al.; Salmonella choleraesuis was isolated in pure or mixed bacterial cultures from 153 swine necropsied between Jan 1, 1987 and Dec 31, 1990 . Pneumonia was seen in 99 of 109 swine from which this bacterium was isolated in the absence of other pathogenic bacteria . Pneumonia was seen more frequently than hepatitis, splenomegaly, or colitis . Pleuropneumonia that was grossly indistinguishable from the pleuropneumonia associated with Actinobacillus pleuropneumoniae was seen in 29 of 99 swine from which S choleraesuis was the only bacterium isolated. Poult Sci, 1992 Nov, 71(11), 1842 - 8 Effect of induced molting on the course of infection and transmission of Salmonella enteritidis in white Leghorn hens of different ages; Holt PS et al.; Previous work in the authors' laboratory had shown that inducing molt using a 2-wk feed removal protocol in 58- to 84-wk-old White Leghorn hens increased the severity of intestinal infection by Salmonella enteritidis (SE) . As susceptibility to infection can be influenced by age, a study was conducted to compare the effect of the feed removal on infection by SE in 20-, 40-, and 74-wk-old hens . Birds were orally infected with 5 to 10 x 10(6) SE on Day 4 of fast and were sampled for SE shedding 3, 10, 17, and 24 days later . Significantly higher numbers of SE were shed in fasted birds on Day 3 (20 and 40 wk of age), Day 10 (40 and 74 wk of age), and Day 17 (74 wk of age) . Transmission of SE to uninfected, contact-exposed birds was observed in all three trials for both the fed and fasted groups . However, significantly more fasted contact-exposed birds became positive for SE on Day 3 (20-wk-old), Day 10 (74-wk-old), and Day 17 (74-wk-old) . Significantly more SE was also shed in these fasted contact-exposed birds on Day 3 (20-wk-old), Day 10 (all age groups), and Day 17 (74-wk-old) . The current results indicate that the fasting conditions used to induce a molt in hens increase the shedding of SE in direct-infected and contact-exposed hens and this effect does not appear to be affected by age. Toxicol Ind Health, 1992 Nov-Dec, 8(6), 369 - 76 Mutagenic activity of p-toluenesulfonhydrazide; Blakey DH et al.; Toluenesulfonhydrazide (TSH) is a high volume production chemical for which there is relatively little toxicological data . In this study, the mutagenic activity of TSH was determined in the Salmonella/mammalian microsome assay and the in vitro chromosomal aberration assay using Chinese hamster ovary cells . TSH induced gene mutations both with and without metabolic activation in the Salmonella/mammalian microsome assay but that it did not induce chromosomal aberrations in Chinese hamster ovary cells . The results of this study indicate that TSH is an in vitro mutagen and should be assessed for in vivo mutagenicity. J Antimicrob Chemother, 1992 Nov, 30(5), 707 - 11 Randomized prospective study comparing two dosage regimens of ciprofloxacin for the treatment of typhoid fever; Uwaydah AK et al.; Sixty-two patients with blood culture-proven typhoid fever were randomly assigned to receive either 500 or 750 mg of ciprofloxacin orally, twice daily for 7 days or for two days following defervescence, whichever was greater . Thirty-four and 28 patients received 500 mg and 750 mg respectively . Strains of Salmonella typhi resistant to ampicillin, chloramphenicol and co-trimoxazole were isolated from the blood of 27 patients (43.5%) . No resistance to ciprofloxacin was encountered . Both regimens were equally effective; fever subsided in mean times of 4.9 +/- 1.7 days in the 500 mg group and 5.2 +/- 2.2 days in the 750 mg group (P = 0.54) . All patients were cured, although one patient in the 750 mg group experienced a presumed relapse two months following completion of therapy . Ciprofloxacin administered for 7-10 days was adequate treatment for 57 of the 62 patients (92%); only five patients required therapy for more than 10 days . Patients with pretreatment symptoms of > or = 10 days duration defervesced in a mean of 5.7 +/- 2.3 days compared with 4.5 +/- 1.3 days (P = 0.01) for those with symptoms of shorter duration . We conclude that 500 mg of ciprofloxacin taken orally twice daily is adequate treatment for typhoid fever. Enferm Infecc Microbiol Clin, 1992 Nov, 10(9), 539 - 42 {Multi-resistant strains of Salmonella typhi in Spain}; Usera MA et al.; Most Salmonella typhi isolated in Spain are susceptible to antibiotics commonly used in its treatment as chloramphenicol, ampicillin and cotrimoxazole . Three multiresistant strains have been isolated from different patients the last two years . Two phage type M1, biotype xylose tetrationate + strains were isolated from blood of two patients in Bembibre (Leon) . One phage type E1a biotype xylose + tetrationate reductase + strain was isolated from blood and faeces of one patient in Barcelona . All strains harboured a 79 Mdal plasmid responsible for multiresistance, chloramphenicol acetyl transferase production and conjugative. Environ Health Perspect, 1992 Nov, 98, 227 - 34 Development of source testing, analytical, and mutagenicity bioassay procedures for evaluating emissions from municipal and hospital waste combustors; Watts RR et al.; Incineration is currently being used for disposal of about 10% of the solid waste generated in the United States, and this percentage will likely increase as land disposal declines . Siting new incinerators, however, is often controversial because of concerns related to the possibility of adverse health effects and environmental contamination from long-term exposure to stack emissions . Specific concerns relate to the adequacies of a) stack emission testing protocols, b) existing regulations, and c) compliance monitoring and enforcement of regulations . U.S . Environmental Protection Agency laboratories are cooperatively conducting research aimed at developing new testing equipment and procedures that will allow a more comprehensive assessment of the complex mixture of organics that is present in stack emissions . These efforts are directed specifically toward developing source testing equipment and procedures, analytical procedures, and bioassay procedures . The objectives of this study were to field test two types of high-volume source dilution samplers, collect stack samples for use in developing analytical and mutagenicity bioassay procedures, and determine mutagenicity of organics associated with emission particles from two municipal waste combustors and a hospital waste combustor . Data are presented for particle concentrations and emission rates, extractable organic concentrations and emission rates, and Salmonella (Ames) mutagenic potency and emission rates . The mutagenic emission rates and emission factors are compared to other incinerators and combustion sources. Mol Microbiol, 1992 Nov, 6(22), 3257 - 65 The Fis protein: it's not just for DNA inversion anymore; Finkel SE et al.; Higher-order nucleoprotein complexes are associated with many biological processes . In bacteria the formation of these macromolecular structures for DNA recombination, replication, and transcription often requires not only the participation of specific enzymes and co-factors, but also a class of DNA-binding proteins collectively known as 'nucleoid-associated' or 'histone-like' proteins . Examples of this class of proteins are HU, Integration Host Factor, H-NS, and Fis . Fis was originally identified as the factor for inversion stimulation of the homologous Hin and Gin site-specific DNA recombinases of Salmonella and phage Mu, respectively . This small, basic, DNA-bending protein has recently been shown to function in many other reactions including phage lambda site-specific recombination, transcriptional activation of rRNA and tRNA operons, repression of its own synthesis, and oriC-directed DNA replication . Cellular concentrations of Fis vary tremendously under different growth conditions which may have important regulatory implications for the physiological role of Fis in these different reactions . The X-ray crystal structure of Fis has been determined and insights into its mode of DNA binding and mechanisms of action in these disparate systems are being made. J Biochem (Tokyo), 1992 Nov, 112(5), 604 - 8 Cloning and expression of the Klebsiella pneumoniae galactose operon; Peng HL et al.; The entire galactose (gal) operon of Klebsiella pneumoniae was isolated and functionally analyzed in Escherichia coli . The genes encoding galactokinase (galK), galactose-1-phosphate uridyltransferase (galT), and UDP-galactose-4-epimerase (galE) were mapped by complementation analysis . The gene order E-T-K was found to be identical to that of Salmonella spp . and E . coli . Analysis of the nucleotide sequence in the control region revealed significant homology with that of E . coli . Two major sites for transcriptional initiation, both mapped to a cytosyl residue, were identified by primer extension . When the operon is expressed in E . coli, the K . pneumoniae gal gene products make up about 30% of the total cellular proteins . The presence of a powerful promoter responsible for high level synthesis of the gal proteins was also demonstrated using beta-galactosidase as reporter. Immunology, 1992 Nov, 77(3), 456 - 61 HLA-B27/microbial mimicry: an in vivo analysis; Kapasi K et al.; The association between three major spondyloarthritic diseases, ankylosing spondylitis, Reiter's syndrome, and reactive arthritis, and the major histocompatibility complex (MHC) class 1 antigen HLA-B27 is well documented . The hypothesis of cross-reactivity between HLA-B27 and the antecedent infection-causing Gram-negative pathogens such as Salmonella, Shigella and Yersinia has been suggested by in vitro studies employing monoclonal antibodies . We have examined the possibility of such cross-reactivity in vivo using various rabbit immune sera and patient sera as the source of cross-reacting antibody . Mouse L cells were transfected with HLA-A3 or HLA-B27 and used as a source of antigen . Western blot analysis employing denatured antigen, FACS analysis employing native antigen and immunoprecipitation studies were undertaken to detect cross-reacting antibodies generated in vivo to HLA-B27 antigen . Antibodies generated in vivo by infection in patients or immunization in animals against arthritogenic bacteria did not demonstrate any cross-reactivity with HLA-B27 by any of the methods used . As defined by the humoral immune response, molecular mimicry appears unlikely to explain the role of B27 in the pathogenesis of reactive arthritis. Diagn Microbiol Infect Dis, 1992 Nov-Dec, 15(8), 651 - 6 Diagnosis of typhoid fever by two serologic methods . Enzyme-linked immunosorbent assay of antilipopolysaccharide of Salmonella typhi antibodies and Widal test; Quiroga T et al.; Serum samples from 85 patients with proven typhoid fever, 11 patients with p-typhoidal fever, 101 patients with febrile non-typhoidal, and 130 healthy subjects were tested for immunoglobulin G (IgG), IgA, and IgM antilipopolysaccharide (LPS) of Salmonella typhi antibodies by enzyme-linked immunosorbent assay (ELISA) and Widal test . The levels of all three classes of immunoglobulin anti-LPS of S . typhi were higher in typhoid patients than in healthy or febrile nontyphoidal groups; we selected various combinations between the three classes of immunoglobulin to obtain the best combination of sensitivity and specificity . The sum of the absorbance values obtained from the ELISA assay for IgG+IgA+IgM (sigma lgs) was the best choice for diagnostic utility for typhoid fever . We selected a positive test at a decision level of sigma lgs > or = 1.2 with a sensitivity of 94% and a specificity of 92% with a frequency of false negative of 5.9% . The frequency of false positives for healthy controls was 7.7% and, for the febrile nontyphoidal group, it was 7.9% . We also compared receiver (or relative) operating characteristic (ROC) curves for the diagnostic usefulness of the ELISA with that of the Widal test, whose merits and limitations, especially in endemic regions, are discussed . The ELISA assay was much more sensitive and specific than any combination of the Widal test, and hence it could be a useful tool for the serologic diagnosis of typhoidal fever with a single blood sample. Clin Infect Dis, 1992 Nov, 15 Suppl 1, S259 - 62 Evaluation of new anti-infective drugs for the treatment of chronic carriage of Salmonella . Infectious Diseases Society of America and the Food and Drug Administration; Corrado ML et al.; The chronic carriage of salmonellae is defined as the shedding of a Salmonella species for > or = 1 year, as documented by an initial positive culture of a stool sample obtained at least 1 month after resolution of the acute illness and repeated positive cultures for at least 1 year . Clinical trials of investigational anti-infective drugs for the treatment of the salmonella carrier state may be conducted with a placebo control or an active concurrent control . A crossover design also may be employed for establishing efficacy . Patients should generally receive therapy for at least 6 weeks . Outcome will be assessed only by microbiological criteria . Determination of the interval required for the suppression of salmonellae and follow-up for 6 months after completion of therapy are recommended. Clin Infect Dis, 1992 Nov, 15 Suppl 1, S236 - 40 Evaluation of new anti-infective drugs for the treatment of typhoid fever . Infectious Diseases Society of America and the Food and Drug Administration; Corrado ML et al.; Typhoid fever is an acute febrile illness caused by Salmonella typhi . The evidence of blood-borne infection required for study entry includes clinical signs and symptoms plus confirmation of the presence of S . typhi in blood or other tissues or body fluids . The preferred study design is prospective and randomized with an active concurrent control . It is preferred that the investigator or an evaluator be blinded to therapy . In general, treatment should be administered for 2 weeks until it is demonstrated that a shorter course is as efficacious and as safe . Follow-up cultures of specimens from sites originally shown to be infected with S . typhi should be performed unless the diagnostic procedure places the patient at unnecessary risk. J Immunother, 1992 Nov, 12(4), 242 - 6 Induction of circulating phospholipase A2 activity by intravenous infusion of endotoxin in patients with neoplasia; Pruzanski W et al.; The purpose of this study was to evaluate the impact of repeated intravenous infusions of endotoxin (EN) in patients with cancer on the systemic release of extracellular proinflammatory phospholipase A2 (PLA2) and its relationship to the release of tumor necrosis factor (TNF) and interleukin-6 (IL-6) . Six patients received 15 infusion of EN isolated from Salmonella abortus equi at a dose of 4 ng/kg . Marked increase in the activity of circulating PLA2 was noted within 3 h after the first EN infusion and reached a maximal level of 20.4-fold greater than baseline 24 h after infusion . In five patients challenged with EN 2 weeks later, PLA2 reached peak levels 15.5-fold greater than baseline . In two patients who received three sequential daily infusions, the incremental increase in PLA2 activity after the second and third challenge reached maximum levels 6 h after EN infusion . PLA2 response followed those of TNF and IL-6 but was quantitatively different . Whereas maximal levels of TNF and IL-6 declined substantially after repeat EN challenges, no such decline occurred in PLA2 activity . Since, in the clinical setting of gram-negative sepsis, there is recurrent increase in circulating EN, our study approximates this clinical situation and shows that extracellular release of PLA2 follows temporally that of proximal cytokines such as TNF and IL-6 . These cytokines may be related to PLA2 release and sustained high activity in the systemic circulation.(ABSTRACT TRUNCATED AT 250 WORDS) Mutagenesis, 1992 Nov, 7(6), 421 - 5 Mutagens in urban air particulate; Nardini B et al.; Extracts of airborne particulate matter were demonstrated to be mutagenic in the Salmonella/microsome test . Urban airborne particulate was collected with high-volume samplers in an Italian town mainly polluted by traffic exhaust fumes . After being weighted for determination of total dust, the particulate was extracted with CH2Cl2/methanol and assayed by Salmonella/microsome assay on strains TA98, TA100 and TA98NR . All samples were mutagenic on strain TA98, with a mutagenic potency of 50 +/- 14 (-S9), 128 +/- 63 (+S9) and 104 +/- 51 (-S9), 211 +/- 97 (+S9) revertants/mg of particulate for summer (n = 23) and winter (n = 22) determinations, respectively . The mutagenic activity on strain TA98NR was about one-half that on strain TA98, indicating a large contribution of nitroaromatic mutagenic compounds . Mutagens from airborne particulate were less active on strain TA100 . The summer and winter mean values of urban total dust were 0.15 +/- 0.07 and 0.35 +/- 0.18 mg/m3 respectively, and the mutagenicity of urban air on strain TA98 was 8 +/- 5 (-S9), 22 +/- 17 (+S9) and 30 +/- 11 (-S9), 61 +/- 21 (+S9) revertants/m3 in the two seasons, respectively . In winter, besides an increase in urban air mutagenicity, there also was a change in direct particulate activity per milligram, which was double that of summer. Food Chem Toxicol, 1992 Nov, 30(11), 979 - 92 Liver medium-term bioassay in rats for screening of carcinogens and modifying factors in hepatocarcinogenesis; Hasegawa R et al.; The present report describes a study of the hepatocarcinogenic potential of a second large assay series of 94 compounds carried out using the rapid bioassay system (DEN-PH model) developed in this laboratory and based on the two-step concept of hepatocarcinogenesis . Male F344 rats were initially given a single dose of diethylnitrosamine (DEN, 200 mg/kg body weight ip) and, starting 2 wk later, were treated with test compounds for 6 wk and then killed, all rats being subjected to a two-thirds partial hepatectomy at wk 3 . Carcinogenic potential was scored by comparing the numbers (no./cm2) and areas (mm2/cm2) of induced glutathione S-transferase placental form (GST-P) positive foci in the livers of groups of about 15 rats with those of corresponding control groups given DEN alone . Positive was scored for a significant increase (P < 0.05) in quantitative values of GST-P positive foci, negative for no change or a decrease . Results for the 94 compounds were also compared with previously published data from Salmonella/microsome (Ames) tests and long-term carcinogenicity studies in rats and mice . Of the known liver carcinogens, 14 out of 14 (100%) mutagenic (Ames test) compounds and 10 out of 12 (83%) non-mutagenic compounds gave positive results in our DEN-PH system (mean 92%) . Two hepatocarcinogenic peroxisome proliferators did not enhance the development of GST-P positive foci . Carcinogens other than hepatocarcinogens gave fewer positive results (five out of 17, 29%) . One of the 13 compounds reported as non-carcinogenic, malathion, gave positive results in the DEN-PH assay, suggesting that this compound is a weak hepatocarcinogen or tumour promoter for hepatocarcinogenesis based on the two-stage hypothesis for carcinogenesis . The present study also provided information regarding the inhibitory potential of nine compounds . The practical usefulness and benefits of the DEN-PH protocol for the rapid screening of carcinogenic agents are discussed. Berl Munch Tierarztl Wochenschr, 1992 Nov 1, 105(11), 383 - 6 {The selection of Salmonella gallinarum, Salmonella pullorum and Escherichia coli in chickens after chloramphenicol administration}; Iliadis N; The effect of a chloramphenicol administration was examined on the selection of E . coli of the chicken intestinal flora, and of the infectious S . gallinarum and S . pullorum strains . On the other hand, an effort was made to detect the frequency of the resistance transmission of E . coli to above mentioned sensitive salmonella strains . Fourteen chicken, 12 infected and 2 negative controls were used . It was found that the enteric E . coli strains became resistant in a week's time . Besides, the strains that were used for infecting the chicken neither were selected through the chloramphenicol administered nor did they take the E . coli resistance, via R-factor transmission. J Leukoc Biol, 1992 Nov, 52(5), 529 - 36 Activation of human monocyte chemiluminescence response by acylpoly(1,3)galactosides derived from Klebsiella pneumoniae; Kouassi E et al.; The stimulating activity of several preparations isolated from a membrane proteoglycan of a nonencapsulated smooth strain of Klebsiella pneumoniae (Kp-MPG) on the oxidative burst of human blood monocytes was assessed by luminol-enhanced chemiluminescence (CL) . Five Kp derivatives were studied: a 34-kd acylpoly(1,3)galactoside (APG), obtained by drastic alkaline hydrolysis and purified by chromatography; an APG preparation subjected to acid hydrolysis that removed the core part and all fatty acids, leaving intact the galactose chain of APG (GC-APG); an APG preparation subjected to mild oxidation (ox APG); a preparation obtained by mild alkaline hydrolysis of Kp-MPG, containing additional ester-linked C14 and C16 fatty acids bound to the APG molecule (EFA-APG); and a polymer of the latter compound, APG pol . EFA-APG directly stimulated monocyte CL, whereas Kp-MPG, APG pol, and the whole bacterial cells had little or no activity . APG itself and ox APG induced a weaker response than EFA-APG . Polymyxin B sulfate completely inhibited the CL response to bacterial lipopolysaccharide (LPS) but not to EFA-APG . The stimulating action of EFA-APG on blood monocytes was dependent on the extracellular levels of both calcium and magnesium . Preincubation of monocytes with monoclonal antibody anti-Mac-1 directed against CD11b, the alpha chain of complement receptor type 3 (CR3; CD11b/CD18), strongly inhibited CL activation by EFA-APG and to a lesser extent CL activation by unopsonized zymosan and rough LPS . Altogether, these findings provide indirect evidence for the contribution of the CD11b/CD18 integrin in the functional interaction of EFA-APG with monocyte membranes . They demonstrate the role of fatty acids in the triggering of monocyte oxidative burst, while the polysaccharide chain itself does not contribute to induction of the CL response in this model . In keeping with the effects of EFA-APG and APG, we show that the monocyte CL response was triggered by bacterial LPS from the rough strain of Salmonella minnesota Re 595 and its lipid A, but not by LPS from smooth strains, again suggesting a critical role for the lipid moiety. J Immunol, 1992 Nov 1, 149(9), 3045 - 51 Lipopolysaccharide induces Egr-1 mRNA and protein in murine peritoneal macrophages; Coleman DL et al.; Bacterial LPS has diverse effects on the function of immune cells, in general, and macrophages, in particular . The intracellular molecular events that mediate the effects of LPS are unclear . We undertook a series of studies in thioglycollate-elicited murine peritoneal macrophages to evaluate the effect of LPS on expression of Egr-1, a member of the immediate early response gene family . Egr-1 may function as an intranuclear "third messenger" because it is rapidly induced in a variety of cell types and encodes a 75- to 80-kDa nuclear phosphoprotein that activates transcription of genes containing the DNA consensus sequence GCGGGGGCG . LPS from Salmonella minnesota Re595 induced a maximal increase in Egr-1 mRNA in macrophages after 30 to 60 min of incubation that returned to baseline level by 120 min . LPS increased Egr-1 mRNA at 0.01 to 0.1 ng/ml with a maximal effect at 10 to 100 ng/ml . LPS markedly increased the transcription rate of Egr-1 by 10 min of incubation using nuclear run on analysis . Using a polyclonal anti-Egr-1 antibody, nuclear staining for Egr-1 protein was prominent after 1 to 2 h of incubation with LPS and declined to baseline by 4 h . Inasmuch as protein kinase C (PKC) has been implicated in mediating the effects of LPS, we determined whether PKC was required for LPS to increase Egr-1 mRNA . Two pharmacologic approaches were used to deplete PKC, PMA pretreatment, and H-7 . The induction of Egr-1 mRNA by LPS was markedly reduced in PKC-depleted macrophages . These data reveal that LPS induces transcriptional activation of Egr-1 and increases Egr-1 protein in peritoneal macrophages . In addition, these findings support further study of the potential role of Egr-1 in mediating the effects of LPS in peritoneal macrophages. J Bacteriol, 1992 Nov, 174(21), 6886 - 95 Evolutionary genetics of the proline permease gene (putP) and the control region of the proline utilization operon in populations of Salmonella and Escherichia coli; Nelson K et al.; Virtually complete sequences (1,467 bp) of the proline permease gene (putP) and complete sequences (416 to 422 bp) of the control region of the proline utilization operon were determined for 16 strains of Salmonella, representing all eight subspecies, and 13 strains of Escherichia coli recovered from natural populations . Strains of Salmonella and E . coli differed, on average, at 16.3% of putP nucleotide sites and 17.5% of control region sites; the average difference between strains was much larger for Salmonella strains (4.6% of putP sites and 3.4% of control region sites) than for E . coli (2.4 and 0.9%, respectively) . There was no difference in the distribution of polymorphic amino acid positions between the membrane-spanning and loop regions of the permease molecule, and rates of synonymous nucleotide substitution were virtually the same for the two domains . Statistical analysis yielded evidence of three probable cases of intragenic recombination, including the acquisition of a large segment of putP by strains of Salmonella subspecies VII from an unidentified source, the exchange of a 21-bp segment between two strains of E . coli, and the acquisition by one strain of E . coli of a cluster of 14 unique polymorphic control region sites from an unknown donor . An evolutionary tree for the putP and control region sequences was generally concordant with a tree for the gapA gene and a tree based on multilocus enzyme electrophoresis, thus providing evidence that for neither gene nor for enzyme genes in general has recombination occurred at rates sufficiently high or over regions sufficiently large to completely obscure phylogenetic relationships dependent on mutational divergence . It is suggested that the recombination rate varies among genes in relation to functional type, being highest for genes encoding cell surface and other proteins for which there is an adaptive advantage in structural diversity. Infect Immun, 1992 Nov, 60(11), 4881 - 90 Characterization and protective properties of attenuated mutants of Salmonella choleraesuis; Kelly SM et al.; We have constructed crp::Tn10 and cya::Tn10 Salmonella choleraesuis mutants and their fusaric acid-resistant derivatives with deletions (delta) of the Tn10 and adjacent DNA sequences and found them to be avirulent and able to induce protection against a wild-type challenge in 8-week-old BALB/c mice . Mice survived infection with the crp and cya mutants at doses of more than 7 x 10(3) times the oral (p.o.) 50% lethal dose (LD50) and more than 8 x 10(2) times the intraperitoneal LD50 of the wild-type S . choleraesuis parent . Mice vaccinated with attenuated strains were protected against challenge with more than 1.6 x 10(4) times the p.o . LD50 and more than 80 times the intraperitoneal LD50 of the wild-type virulent S . choleraesuis parent . One deletion mutation isolated in the crp region extends to an adjacent gene(s) that was shown to be associated with avirulence . This gene or operon has been designated cdt (colonization of deep tissues) . A delta (crp-cdt)19 strain, when complemented with the wild-type crp gene and promoter on a pBR-derived plasmid, had p.o . LD50 values 10(3) times higher than those for the wild type . A delta cya delta (crp-cdt)19 double mutant was less virulent than and afforded more complete protection against a challenge with the wild-type strain than a delta crp-11 delta cya double mutant or the individual cya, crp, or crp+/cdt mutants . The deletion derivatives exhibited reduced invasion of CHO cells in vitro, and the numbers of the mutants recovered from mouse tissues were less than that of the parent strain . These studies suggest that one or more of the genes involved in cell attachment to and/or invasion of S . choleraesuis may be under catabolite repression . In addition, we describe a new deletion of a gene(s) located in the crp region between cysG and argD that is associated with virulence in S . choleraesuis. Res Vet Sci, 1992 Nov, 53(3), 300 - 8 Characterisation of monoclonal antibodies against a fimbrial structure of Salmonella enteritidis and certain other serogroup D salmonellae and their application as serotyping reagents; Thorns CJ et al.; A panel of 13 monoclonal antibodies from different hybridomas was produced against a novel salmonella fimbrial antigen expressed predominantly by Salmonella enteritidis strains . The specificity of the monoclonal antibodies to this antigen (SEF14) was confirmed by enzyme-linked immunosorbent assay (ELISA) using purified SEF14, immune electron microscopy and, with 11 monoclonal antibodies, the identification of a repeating protein subunit (14,300kDa) on the antigen . Blocking-ELISA with the monoclonal antibodies identified epitopes in at least three, non-overlapping clusters which appeared evenly distributed on SEF14 in immune electron microscopy . The use of the monoclonal antibodies in direct-binding ELISA on a range of salmonella serotypes suggested that the epitopes on SEF14 are highly conserved and were expressed by all the S enteritidis strains examined; some strains of S dublin and the only strain of S moscow available were the only other serotypes that expressed SEF14 . A latex agglutination reagent based on a monoclonal antibody was developed and used to test for SEF14 on 280 strains (representing 120 serotypes in 24 serogroups of salmonellae) that had been grown on Sensitest agar for 18 hours at 37 degrees C . All S enteritidis strains (64) and most S dublin strains (28 of 33) produced SEF14 as did the two strains representing S blegdam and S moscow . SEF14 was not detected in any other strains of serotypes from serogroup D or from any other serogroup examined. J Gen Microbiol, 1992 Nov, 138 ( Pt 11), 2329 - 36 The insertion sequence IS200 fingerprints chromosomal genotypes and epidemiological relationships in Salmonella heidelberg; Stanley J et al.; In Salmonella heidelberg the copy number of the Salmonella-specific insertion element IS200 was found to vary from four to six . All strains tested contained at least one common insertion site which was serovar specific, and most strains contained three common sites . Concurrent analysis of plasmids indicated that all insertion sequence copies were chromosomally located, and also supported the equivalence of an IS200 fingerprint and clonality . Seven intra-serovar clonal lines were thereby identified . One of these was associated with human infections, including septicaemias . Another was associated with chicken as a host: all these strains also carried a unique plasmid of 23 MDa, which was typed as a member of the IncX group . The chromosomal fingerprint of a third clone showed it to be a descendant of the chicken line marked by a single IS200 transposition . One or two representatives of four other clonal lines were identified . These lines of S . heidelberg could be related by divergent evolution, and the most recent relatives conformed to a continuous branching process model of IS200 transposition . This insertion sequence provided a highly discriminatory molecular marker of the S . heidelberg chromosome, and two of the seven clonal lines so identified were associated with distinct clinical/epidemiological contexts. Infect Immun, 1992 Nov, 60(11), 4932 - 7 Lipopolysaccharides of Bacteroides intermedius (Prevotella intermedia) and Bacteroides (Porphyromonas) gingivalis induce interleukin-8 gene expression in human gingival fibroblast cultures; Tamura M et al.; Lipopolysaccharides (LPS) prepared from Bacteroides intermedius (Prevotella intermedia) and Bacteroides (Porphyromonas) gingivalis by hot phenol-water extraction induced interleukin-8 (IL-8) mRNA in normal human gingival fibroblast cultures, as demonstrated by Northern (RNA) blot analysis . IL-8 mRNA levels began to increase after a 2-h exposure, reached a maximum after 12 h, and then dropped to the unstimulated level at 48 h . IL-8 mRNA levels were also enhanced in a dose-dependent manner . By contrast, LPS specimens from various Salmonella species with S and R chemotypes and bacterial {corrected} and synthetic lipid A preparations did not increase IL-8 mRNA levels in fibroblasts . Although recombinant human IL-1 alpha induced IL-8 mRNA expression in fibroblast cultures, an antiserum to recombinant human IL-1 alpha did not decrease the IL-8 mRNA accumulation induced by B . intermedius LPS . Fibroblasts primed with natural human gamma interferon (IFN-gamma) expressed higher IL-8 mRNA levels upon stimulation with B . intermedius LPS, but not with Salmonella LPS, compared with nontreated cells . Natural human IFN-beta exhibited a similar priming effect on the fibroblasts, and antiserum to IFN-beta added to the cultures together with B . intermedius LPS decreased the IL-8 mRNA levels . Therefore, endogenous IFN-beta enhanced IL-8 mRNA production in response to B . intermedius LPS in fibroblasts. J Assoc Physicians India, 1992 Nov, 40(11), 733 - 5 Retrospective treatment analysis of Salmonella infections; Gokhale YA et al.; Twenty four culture proved and nine postmortem histopathology proved cases of enteric fever were analysed retrospectively with special interest in use of various antisalmonella agents . Chloramphenicol resistance was noted in 91.7% and yet 70% of all patients received chloramphenicol alone or in combination with another antisalmonella agent . Time required for remission of fever with chloramphenical, cotrimoxazole and ciprofloxacin was 4.5, 4.1 and 6.9 days respectively . An interesting feature noted in post-mortem histopathology proved cases was enteric carditis which was documented on postmortem examination of the heart in three out of four patients who died of peripheral circulatory failure. J Assoc Physicians India, 1992 Nov, 40(11), 729 - 32 Chloramphenicol resistance in Salmonella typhi . Report from Bombay; Rodrigues C et al.; Chloramphenicol resistance to Salmonella typhi in 1989 was 16% in Hinduja Hospital . From Jan to June 1990, this resistance has increased to 81% . 74 strains of blood culture isolated of S typhi obtained from Jan to June were subjected to antibiotic sensitivity testing by disc diffusion technique of Kirby and Bauer 60 strains were found to show a block resistance tochloramphenicol, Ampicillin, Co-trimoxazole, Streptomycin, Tetracycline and Carbenicillin . All strains were sensitive to quinolones . Resistance was record and MIC done in 50 resistant strains by modified National Committee for Clinical Laboratory Standards {NCCLS} according to recommended break points and resistance to Chloramphenicol was confirmed . Of the 47 strains isolated, 34 had received treatment with either chlorampheniicol, Ampicillin or Cotrimoxazole in adequate dosages . In 39 of these 47 patients, Salmonella typhi was isolated after 14 days duration of fever . Plasmid analysis revealed presence of 100 megadalton plasmid in majority of cases . Most patients responded to fluoroquinolones but amongst the admitted patients complications such as Myoglobinuria in 2 cases, perforation in 4 cases, acute Renal failure in 2 cases and typhoid spine in 1 case were seen . Phage typing results of 19 strains were E-8, 0-6. Zh Evol Biokhim Fiziol, 1992 Nov-Dec, 28(6), 678 - 84 {The fever reaction of the polecat Mustela putorius x Mustela putorius furo to a bacterial pyrogen: the hypo- and hyperthermic phases}; Romanovskii AA et al.; It has been demonstrated that the ferret (Mustela putorius x Mustela putorius furo) responds to intramuscular injection of Salmonella typhi lipopolysaccharide (30 ng/kg-100 micrograms/kg) by biphasic change in the body temperature (Tb): the initial decrease in the latter is followed by hyperthermia . Maximum rise in Tb (1.6 +/- 0.1 degrees C) was observed after the injection of lipopolysaccharide in the highest dose . Rabbit leucocytic pyrogen/interleukin-1 (1 ml from 3.5 x 10(7) peritoneal phagocytes, 3 ml/kg) induces a pronounced (1.1 +/- 0.3 degrees C) decrease in Tb . Mechanisms of hypothermic effects of pyrogens are discussed . The described pattern (hypothermia-hyperthermia) of Tb response to lipopolysaccharide in the ferret presumably reflects the central thermoregulatory process which is the same for different changes in Tb during fever. Minerva Pediatr, 1992 Nov, 44(11), 559 - 63 {Schoenlein-Henoch syndrome and salmonella infection: a new association?}; Zucchini A et al.; Schoenlein-Henoch's disease has a immunological pathogenesis (mediated by immunocomplexes), is characterised by a number of differently associated signs and symptoms, and leads to the possible involvement of the cutis, joints, abdomen and kidneys . Two cases of Schoenlein-Henoch's disease associated with acute salmonella enterocolitis were recently brought to our attention . In two girls, aged 2 years and 8 months and 13 months respectively, the onset of diarrheic alvus was followed, after an interval of 4-5 days, by the sudden appearance of pompho-erythemato-hemorrhagic and petechial cutaneous lesions localised symmetrically on the extensor surfaces of the lower limbs and buttocks, and accompanied in the first case by intense abdominal pain and in the second by diffuse arthralgia, with predominant involvement of the tibio-tarsal joints . Laboratory tests showed slight alterations of phlogosis indexes and high levels of serum IgA (182 and 204 mg/dl respectively) . The examination of feces showed the presence of occult blood and salmonella (belonging to C and D groups respectively) were isolated in the coproculture . Other culture and serological tests carried out while in hospital were negative . The clinical manifestations gradually resolved within the space of two weeks following the normalisation of the alvus obtained after a few days using dietary regulation . After two months the girls were found negative on clinical examination; in the second case described there was a positive response to Widal's reaction with high antibody titres against both O and H antigens, whereas the coproculture continued to be positive for Salmonella.(ABSTRACT TRUNCATED AT 250 WORDS) Eur J Clin Microbiol Infect Dis, 1992 Nov, 11(11), 990 - 3 Widespread occurrence of multiple drug-resistant Salmonella typhi in India; Threlfall EJ et al.; Sixteen multiple drug resistant strains of Salmonella typhi belonging to Vi-phage types E1 (14) and O (2) and isolated in Southeast India in 1991 were characterized . All strains were resistant to chloramphenicol and the majority to trimethoprim and ampicillin . In all strains these resistances were encoded by plasmids of the H1 incompatibility group with molecular weights ranging from 110 to 120 megadaltons . Physicians in European countries should be aware that treatment may fail if patients with typhoid fever who have recently returned from the Indian sub-continent are given first-line treatment with chloramphenicol, trimethoprim or ampicillin . With the possible exception of young children, ciprofloxacin is currently the best choice for treatment of such patients. Eur J Epidemiol, 1992 Nov, 8(6), 851 - 5 Epizootics of Salmonella infection in poultry may be the result of modern selective breeding practices; Hunter PR; This paper discusses the hypothesis that a major factor in the epizootics of Salmonella infection in poultry is a declining host genetic diversity . A computer model is described which is based on models that have been previously used to investigate host-pathogen coevolution in cereal crops . It is shown that, as host genetic diversity declines, parasite diversity also declines to a lower equilibrium level . With a highly diverse host, parasite numbers decline to zero . With a homogeneous host population, after an initial decline, there is a rapid increase in parasite numbers, due to the selection of a particularly well adapted parasite strain . This simple computer simulation is used as the basis for a discussion of the literature supporting the suggestion that a major factor in the epizootic of Salmonella in poultry is related to the low genetic diversity of commercial poultry flocks. J Cardiovasc Surg (Torino), 1992 Nov-Dec, 33(6), 732 - 4 Salmonella infection of a Dacron aortic bifurcation graft; Russell AJ et al.; We report a case of primary salmonella infection of a dacron aortofemoral bypass graft . Local graft excision with extra-anatomic bypass resulted in a successful outcome . Salmonella, whilst the commonest cause of infected abdominal aortic aneurysms, is currently a rare cause of prosthetic graft infection . However, given the increasing prevalence of salmonellosis in the community, we believe this situation will change and surgeons should be alert to this new and dangerous addition to the list of graft pathogens. Immunobiology, 1992 Nov, 186(5), 378 - 93 Immunosuppressive effects induced by the polysaccharide moiety of some bacterial lipopolysaccharides; Haslov K et al.; The immunomodulatory properties of several lipopolysaccharides (LPS) derived from clinical isolates of Pseudomonas aeruginosa, Branhamella catarrhalis, and Bordetella pertussis were evaluated for their capacity to influence the magnitude of the antibody response to type III pneumococcal polysaccharide (SSS-III), which is known to be regulated by suppressor and amplifier T cells (Ts and Ta, respectively) . The administration of LPS, two days after immunization resulted in a significant increase in the antibody response . Such enhancement may be due mainly to the ability of the lipid A moiety of LPS to abolish the negative effects of activated Ts, thereby enabling Ta function to be more fully expressed; however, B cell mitogenicity of the LPS molecule also may be involved . By contrast, treatment with LPS at the time of immunization with SSS-III induces significant suppression of the SSS-III-specific antibody response; such suppression is not induced by LPS or lipid A derived from Escherichia coli and Salmonella minnesota, and is independent of the capacity of LPS to activate B cells polyclonally, an activity generally attributed to the lipid A fraction of LPS . Studies conducted with the LPS of P . aeruginosa indicated that the suppression induced is T cell dependent and mediated by the polysaccharide (PS) fraction of LPS; it appears to be due-at least in part-to the capacity of PS to expand or increase the size of the precursor pool of Ts, activated in response to SSS-III . The significance of these findings to the pathogenesis of certain gram-negative infections is discussed. Clin Ther, 1992 Nov-Dec, 14(6), 825 - 8 Enoxacin in the treatment of typhoid fever; Ahmed A et al.; Enoxacin 400 mg twice daily was given orally to 40 patients who had Salmonella typhi- or Salmonella paratyphi-positive blood or bone marrow cultures . One patient was switched to parenteral therapy within 48 hours of study enrollment, but the remaining 39 patients were given enoxacin for 10 to 14 days . All 39 patients were cured by enoxacin, even though 23 (58.9%) strains were resistant to cotrimoxazole and 16 (41%) strains were multiply resistant to ampicillin, chloramphenicol, and cotrimoxazole . No adverse events necessitated the interruption of therapy . In this study, enoxacin was well tolerated and efficacious in the treatment of typhoid fever. Ann Gastroenterol Hepatol (Paris), 1992 Nov-Dec, 28(6-7), 268 - 73 {Food poisoning outbreaks: an epidemiological study}; Buisson Y; The occurrence of foodborne disease outbreaks (FDO) is increasing in industrialized countries . Most of these outbreaks (2/3) are notified from restaurants and other commercial establishments but more and more from households . Salmonella is the major agent of FDO, especially S . enteritidis for five years . However, its role may be overestimated because inadequate microbiological techniques routinely performed . Despite recent progress, several outbreaks still go unnoticed . Every outbreak should be early investigated, with methodical collection of clinical, bacteriological and food data, followed by statistical analysis . Once identified the responsible pathogen, the contaminated food, the source of contamination and the bacterial growth enhancing factors, rapid control measures can prevent further epidemics . Compulsory notification of all FDO to the public health services is the condition for the reliability of a national surveillance programme. Eur Cytokine Netw, 1992 Nov-Dec, 3(6), 571 - 9 Endotoxin tolerance: regulation of cytokine production and cellular changes in response to endotoxin application in cancer patients; Mackensen A et al.; Endotoxin (lipopolysaccharide, LPS) has the property of inducing tolerance to its own biological effects . This phenomenon has been extensively studied in animal models but only few studies exist on the regulation in humans . Here we describe experiments designed to determine the cytokine regulation and cellular changes in humans during induction of LPS tolerance after repeated LPS injections . Intravenous administration of purified LPS Salmonella abortus equi to cancer patients induces high amounts of circulating tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), granulocyte colony-stimulating factor (G-CSF), and macrophage colony-stimulating factor (M-CSF) . Repeated injections of LPS at daily intervals resulted in a marked downregulation of the cytokine response and in the case of TNF-alpha, IL-8, G-CSF, and M-CSF the cytokine response was reduced to baseline levels . In contrast, significant increases in serum IL-6 were detected up to day 5 of repeated LPS injections . Hematological changes included transient decreases in WBCs affecting granulocytes, monocytes, and lymphocytes, followed by a marked granulocytosis . The drop in WBCs remained unaltered throughout the 5 day course of repeated LPS injections whereas the granulocyte overshoot recovery diminished gradually . When PBMCs of the cancer patients were restimulated ex vivo a marked enhancement of the capacity to produce TNF-alpha, IL-113, and IL-6 occurred, which is in contrast to the decreasing TNF-alpha serum levels obtained in vivo . In parallel, a shift in monocyte subpopulations from CD14+/CD16- to CD14+/CD16+ cells was observed . The data provide evidence that different mechanisms are implicated in the cytokine downregulation following repeated LPS injections to cancer patients . Furthermore, PBMCs from LPS tolerant patients do not demonstrate a reduction in their capacity to produce cytokines. FEMS Microbiol Lett, 1992 Nov 1, 77(1-3), 277 - 84 Nucleotide sequence of the nfaA gene encoding the antigen 8786 adhesive factor of enterotoxigenic Escherichia coli; Aubel D et al.; The nucleotide sequence of a 714-bp DNA fragment containing the enterotoxic Escherichia coli (ETEC) adhesive factor 8786 structural gene, designated nfaA, revealed an open reading frame of 498 bp encoding a polypeptide of 166 amino acids . Primer-extension experiments showed that the nfaA gene is within a single transcription unit . No homology was found with the ETEC adhesive factors already sequenced . In contrast, a homology with Salmonella enteritidis fimbrin SEF 14 was observed. Scand J Immunol, 1992 Nov, 36(5), 671 - 9 Adhesion molecules involved in the interaction of LGL/NK cells and human endothelial cells stimulated with Salmonella bacteria; Pinola M et al.; Previously we showed that pretreatment of LGL/NK or HUVE cells with Salmonella bacteria augments the adhesion of LGL/NK cells to endothelium . Here we analyse the roles of HUVEC adhesion molecules VCAM-1, ICAM-1 and E-selectin, and the counter-receptors VLA-4, LFA-1 and SLex in the increase of LGL/NK adhesion to HUVEC, stimulated with Salmonella Minnesota mR595 bacteria, LPS or TNF-alpha . On Salmonella-stimulated HUVEC, VCAM-1 and ICAM-1 were the major binding structures involved, and their effect was additive in monoclonal antibody inhibition experiments . We could demonstrate the induction of both structures on cultured HUVEC after 24 h of Salmonella stimulation in flow cytometric analysis . For Salmonella-stimulated LGL/NK, the principal binding structure was LFA-1 . Stimulation of LGL/NK cells did not alter the expression of the adhesion structures (subunits CD11a/CD18, CD49d/CD29), as determined by flow cytometric analysis, and thus the increased adherence is presumably produced by an increased avidity of the receptors on LGL/NK cells . Pretreatment of endothelium or lymphocytes with various stimuli, including Salmonella bacteria or LPS, leads to an activation state which provides for characteristic anchorage sites for the increased migration of LGL/NK cells towards the site of inflammation. Mutat Res, 1992 Nov, 298(1), 9 - 16 Assessment of the genotoxic potential of riboflavin and lumiflavin . A . Effect of metabolic enzymes; Kale H et al.; The mutagenic potential of riboflavin and its photodegradation product lumiflavin was evaluated using the umu test, SOS chromotest and Ames Salmonella assay . Both riboflavin and lumiflavin by themselves were found to be non-mutagenic . On treatment with rat liver microsomal enzymes (S9) or caecal cell-free extract (CCE), lumiflavin acquired mutagenicity, while the status of riboflavin remained unaffected . Activation of lumiflavin by metabolic enzymes was found to result in an alteration of its spectral characteristics. Mutat Res, 1992 Nov, 298(1), 53 - 60 Mutagenic activity of oxathiolane steroids: structural requirement for the genotoxic activity in Salmonella and E . coli; Qadri SA et al.; Oxathiolanes and disulfonyl derivatives of steroids were tested for mutagenic activity in the Ames tester strains . The test compounds exhibited mutagenic activity without metabolic activation although metabolic activation markedly enhanced their activity . A significant decrease in the survival of the radiation-sensitive mutants recA, lexA and rer of E . coli was observed as compared to their wild-type counterpart in the presence of the test steroid . Structural features which appear to be crucial for the mutagenic activity in these steroidal drugs are: (i) an electron-donating group at position 3, and (ii) a bulky group anchored at the 5th and 6th positions . The test steroids appear to damage DNA which in turn initiates the SOS repair with the concomitant induction of mutation. J Chromatogr, 1992 Oct 30, 624(1-2), 253 - 65 Chromatographic methods for the analysis of heterocyclic amine food mutagens/carcinogens; Knize MG et al.; A series of potent heterocyclic amines that are mutagenic and carcinogenic have been discovered that are formed in some heated foods, most notably, meats derived from muscle . Determining the heterocyclic amine content in foods and food products is required for toxicological research, industry quality control, and possibly in the future, regulatory control . The contents of food needs to be determined using reliable analytical techniques . Since heterocyclic amines are present in foods at ng/g levels, a variety of liquid-liquid or solid-phase purification techniques are required, followed by gas or high-performance liquid chromatography . Peak detection has been successful using UV, fluorescence, and mass spectrometric detection, and biological activity using the Ames/Salmonella test . The low levels present require that chromatographic efficiency, and both detector sensitivity and selectivity be optimized . The cartridge solid-phase extraction and high-performance liquid chromatography method have been used to measure the known food-derived heterocyclic amines for several types of food, and to the authors knowledge, this is the only method undergoing intralaboratory comparison and validation . Our analysis of the literature shows that chromatographic analysis of the heterocyclic amines by high-performance liquid chromatography or gas chromatography (with derivatization) is satisfactory for heterocyclic amine analysis in foods although the methods are just now being optimized for routine use . The biggest improvements in speed and accuracy will probably come from improved extraction methods as analysis of complex food samples for heterocyclic amines will always be a challenge. Vet Rec, 1992 Oct 24, 131(17), 386 - 8 Infection of laying hens with Salmonella enteritidis PT4 by conjunctival challenge; Humphrey TJ et al.; The direct administration of either 103 or 108 cells of Salmonella enteritidis phage type 4 on to the conjunctiva of laying hens resulted in systemic infection . The bacterium was isolated from a variety of tissues, including the ovary and oviduct, and it was excreted in faeces for at least 27 days after infection. J Immunol, 1992 Oct 15, 149(8), 2722 - 8 The disaccharide L-alpha-D-heptose1-->7-L-alpha-D-heptose1-->of the inner core domain of Salmonella lipopolysaccharide is accessible to antibody and is the epitope of a broadly reactive monoclonal antibody; Nnalue NA et al.; We generated a panel of mAb containing at least one specificity against each of the known chemotypes of the Salmonella LPS core domain and used them to investigate the accessibility of core determinants in smooth LPS . Most of the mAb were reactive with at the most three chemotypes of the core as determined by enzyme immunoassay and failed to bind smooth LPS or any of the complete cores of E . coli . One mAb, MASC1-MM3 (MM3), reacted with six different Salmonella core chemotypes, the R2 core of Escherichia coli and a variety of smooth LPS . This mAb reacted equally well with live and heat-killed bacteria . It bound to 123 of 126 clinical isolates of Salmonella and 11 of 73 E . coli strains in a dot-immunoblot assay . Typical ladder-like patterns of bands were observed after immunoblotting of this mAb against electrophoretically resolved smooth LPS from the five major serogroups of Salmonella species (A, B, C1, D1, and E) . MM3 had no reactivity with BSA conjugates of O-Ag polysaccharides from the above serogroups confirming specificity for a core epitope . Polysaccharides derived from or synthetic saccharides representative of the various chemotypes of Salmonella LPS core were tested as competitive inhibitors of the binding of MM3 to LPS . The results led to a conclusion that MM3 recognizes the structure, L-alpha-D-Heptose1-->7-L-alpha-D-Heptose1-->disaccharide present as a branch in the Ra, Rb1, Rb2, Rb3 and Rc but lacking in the Rd1, Rd2, and Re chemotypes of the Salmonella LPS core . This disaccharide seems free and accessible on the basis of the previously calculated conformations of the Salmonella (Ra) and E . coli complete cores (R1, R2, R3, R4, and K12) . It therefore defines or contains an epitope within the inner core subdomain of Salmonella LPS that is accessible to antibody in long-chained LPS and in intact bacteria with complete LPS. Avian Dis, 1992 Oct-Dec, 36(4), 897 - 902 Effect of used litter from floor pens of adult broilers on Salmonella colonization of broiler chicks; Corrier DE et al.; The effect of used pine-shaving litter from broiler floor pens on Salmonella colonization resistance was evaluated in broiler chicks . One-day-old chicks were placed in floor pens on fresh unused litter or on used litter . All chicks were challenged orally with 10(4) S . typhimurium at 3 days of age . The study was replicated in three trials with used litter that was collected and stored for 1 day (Trial 1), 4 days (Trial 2), or 50 days (Trial 3) before the start of each trial . Cecal concentrations of volatile fatty acids (VFAs) were significantly higher (P < 0.05) in chicks placed on used litter than in chicks on new litter . In all three trials, the number of Salmonella in the cecal contents and the number of Salmonella cecal-culture-positive chicks was significantly lower (P < 0.01) at 10 days and 20 days of age in the chicks on used litter than in the chicks on new litter . The results indicated that newly hatched chicks reared on used litter had higher cecal VFA concentrations and higher resistance to Salmonella colonization than chicks reared on new litter. J Appl Toxicol, 1992 Oct, 12(5), 325 - 8 Toxicity of 2-methyl-5,6-cyclopentapyrimidine (MCPP); Kennedy GL Jr; 2-Methyl-5,6-cyclopentapyrimidine (MCPP, CAS No . 36274-29-0) is a white dusty solid with a powerful lingering odor and is formed as a by-product in the polymer synthesis of an experimental polymer . The acute toxicity following both oral and inhalation exposures and the effects of repeated inhalation exposures in rats were determined . Mutagenic activity was assessed using Salmonella as the indicator organism . The chemical is moderately toxic, with the lethal dose following a single oral administration being 90 mg kg-1 . Doses greater than or equal to 130 mg kg-1 produced strong convulsions . Excessive salivation, hyperactivity and twitching were seen at 90 mg kg-1 and only mild initial weight loss was seen in surviving rats (less than or equal to 60 mg kg) . Liver injury was produced at doses as low as 17 (but not at 12) mg kg-1 . The material was highly toxic by inhalation, with the approximate lethal concentration in rats following single 4-h exposures being 9 ppm . Convulsive-like movements were seen at greater than or equal to 9 ppm (not at 2 ppm) . Histological findings suggest that MCPP causes dilation of blood vessels with hyperemia of various organs apparent in rats exposed to 1 ppm and sacrificed 1 or 2 days post-exposure . No evidence of liver or central nervous system damage was seen . Repeated (nine daily 4-h exposures) inhalation of 2 ppm MCPP failed to produce any signs of a toxic response . No mutagenic activity was seen . The material needs to be considered as a potent acute toxin. Br J Hosp Med, 1992 Oct 7-20, 48(7), 378 - 87 Rheumatology and the gut; Ballinger A et al.; Some conditions may present with gastrointestinal and rheumatological manifestations . Salmonella osteomyelitis results from direct infection of bone following gut infection and bacteraemia, but in other conditions the pathogenesis is less clear . There may be a microbial cause for rheumatoid arthritis; however, this theory remains unproven. Med Trop (Mars), 1992 Oct-Dec, 52(4), 447 - 50 {Bacteremia caused by non-typhoid Salmonellas during an infection by the human immunodeficiency virus (HIV) in the African adult}; Aubry P et al.; Infection caused by non-typhous Salmonellae during the course of HIV infection is known since 1983 . The authors report on 103 bacteremiae of this type found in one year . Diagnosis has been based on hemocultures . 86 patients out of 103 were HIV+ . All of them were febrile . 67 suffered from digestive disorders, 33 with diarrhoea . Splenomegalia was noted in 16 cases and consciousness troubles in 13 cases . At the admission, 8 complications were observed . Other infections were associated in 86 cases particularly in HIV+ patients evolutive tuberculosis (38 cases), candidosis of oropharynx (32 cases), neuromeningeal crytococcosis (13 cases), pneumocystosis (3 cases), Kaposi's sarcoma was discovered in 3 cases . The salmonellae isolated were in the 54 cases where characterization was made: Salmonella typhi murium in 44 cases and Salmonella enteridis in 10 cases . Classical cure (chloramphenicol) was effective in 85% of the treated patients . 28 positive hemocultures out of 103 isolated non-typhous Salmonellae were sampled later than the 72th hour after admission . This fact poses the problem of nosocomial infections in hospital departments in Black Africa, where HIV+ patients represent 52% of the admissions . Non-typhous Salmonellae would be part of the definition of African AIDS concerning patients with HIV test positive. Int J Food Microbiol, 1992 Oct, 17(2), 75 - 84 Isolation of Yersinia enterocolitica from foods; de Boer E; Many selective enrichment and plating media for the isolation of Yersinia enterocolitica from foods are described . However, at present no single isolation procedure is available for the recovery of all pathogenic strains of Yersinia enterocolitica . Cold enrichment in phosphate-buffered saline plus 1% sorbitol and 0.15% bile salts (PBSSB) and two-step enrichment with tryptone soy broth (TSB) and bile oxalate sorbose (BOS) broth are very efficient methods for the recovery of a wide spectrum of serotypes of Y . enterocolitica . Enrichment in irgasan ticarcillin chlorate (ITC) broth was found to be the most efficient method for the recovery of strains of serotype 0:3, which is the most common clinical serotype of Y . enterocolitica in Europe . Post-enrichment alkali treatment often results in higher isolation rates . Cefsulodin irgasan novobiocin (CIN) agar and Salmonella-Shigella deoxycholate calcium chloride (SSDC) agar are the most commonly used plating media . For the recovery of serotype 0:8 strains, the common clinical isolates in North America, enrichment in BOS and plating on CIN seems the most efficient procedure . Selection of the proper enrichment procedure will depend on the bio/serotypes of Yersinia spp . sought and on the type of food to be examined . The use of more than one medium for both enrichment and plating will result in higher recovery rates of Yersinia spp . from foods . Parallel use of the following two isolation procedures is recommended . (1) Enrichment in ITC for 2 days at 24 degrees C; plating on SSDC agar (2 days at 30 degrees C) . (2) Pre-enrichment in TSB for 1 day at 24 degrees C; enrichment in BOS for 5 days at 24 degrees C; alkali treatment (mixing 0.5 ml enriched broth with 4.5 ml of 0.5% KOH in 0.5% NaCl for 5 s); plating on CIN agar (2 days at 24 degrees C). Avian Dis, 1992 Oct-Dec, 36(4), 992 - 9 Evaluation of the efficacy of an oil-emulsion bacterin for protecting chickens against Salmonella enteritidis; Gast RK et al.; To assess the potential protective efficacy of a Salmonella enteritidis bacterin, an acetone-killed oil-emulsion vaccine was prepared from a phage type 13a S . enteritidis strain and administered subcutaneously to hens in two experiments . Hens were housed individually, and every other hen was vaccinated (at 23 weeks of age in one experiment and at 45 weeks in the other) . A second (booster) bacterin injection was administered 6 weeks later in both experiments . Three weeks after the second vaccination, all hens were challenged with an oral dose of approximately 10(9) cells of a heterologous (phage type 14b) S . enteritidis strain . In both trials, S . enteritidis was isolated from fewer internal organs (spleens, ovaries, and oviducts) and pools of egg contents from vaccinated hens than from unvaccinated control hens . Vaccination did not, however, affect the percentage of hens that shed S . enteritidis in feces in either experiment. Avian Dis, 1992 Oct-Dec, 36(4), 1076 - 80 Pullorum disease in Delaware roasters; Salem M et al.; An index case of pullorum disease in 4-week-old roasters from a completely integrated poultry operation is reported from Delaware . Severe articular and periarticular swelling of hock and/or wing joints was observed on postmortem examination . Also seen were moderate to severe hydropericardium and large white-gray nodules in the heart and gizzard that grossly could have been taken for tumors . The livers showed multiple small white foci, petechial hemorrhages, and swelling . Initially, Salmonella pullorum was isolated from the articular fluid by direct culture on MacConkey agar, but it was not isolated from liver, spleen, or heart samples after enrichment in selenite broth. Pathol Biol (Paris), 1992 Oct, 40(8), 793 - 6 Novobiocin-brilliant green-glycerol-lactose-agar: further routine evaluation on 5554 human stools and 982 veterinary samples; Poisson DM et al.; In order to provide a wider evaluation of "Novobiocin-brilliant green-glycerol-lactose" (NBGL) agar, dishes of this medium were added to standard media: Hektoen (H), Salmonella-Shigella agar (SS), at all plating steps for 5554 stool cultures of human medical routine (280 isolates) and 982 samples of veterinary routine (133 isolates) . NBGL expectedly missed lactose-glycerol positive strains of the serotype Senftenberg (n = 4), H2S negative strains (n = 1), and strains of the Typhi serotype (n = 7) . Otherwise, three strains, of serotype Virchow, were unable to grow on NBGL (0.7% of positive samples) . Nevertheless overall sensitivities were increased by approximately 10% in the human routine (H: 70%; SS: 63%; NBGL: 94%; at the direct plating step) (H: 83%; SS: 84%; NBGL: 92%; at the enrichment plating step) and by 48% in the veterinary one (NBGL: 97%; versus usual media: 68%) . Positive predictive values of black centred colonies were significantly higher on NBGL in human routine (H: 38%; SS: 40%; NBGL: 89%; at the direct plating step) (H: 20%; SS: 21%; NBGL: 82%; at the enrichment plating step); and in the veterinary one as well (NBGL: 90%; versus usual media: 17%) . These data suggest that NBGL agar does improve Salmonella isolation in these kinds of routines, and that growth should be made sure before experiments using given strains. J Vet Diagn Invest, 1992 Oct, 4(4), 416 - 8 Salmonella enteritidis in commercial layer farms in New York state; environmental survey results and significance of available monitoring tests; Mutalib A et al.; Seven hundred fifty-one environmental samples were collected from 76 chicken layer houses in a voluntary Salmonella enteritidis (SE) survey study carried out in New York state between January 15 and April 8, 1991 . SE was recovered from both houses on 1 farm . Sampling of manure pits and mice in hen houses was useful for SE screening . Phage types of SE from the environment, birds, and mice were identical . The rapid whole-blood test was unreliable, and culture of cloacal swabs was inadequate for detection of SE carriers . Culture of organs from chickens did not correlate well with results of environmental samples. Am J Vet Res, 1992 Oct, 53(10), 1895 - 9 Effect of calf age and Salmonella bacterin type on ability to produce immunoglobulins directed against Salmonella whole cells or lipopolysaccharide; Da Roden L et al.; A commercially available Salmonella bacterin was administered to Holstein calves starting at 1 to 19 weeks of age . Serum samples were obtained before administering bacterin and at 2-week intervals thereafter . An ELISA with Salmonella dublin lipopolysaccharide (LPS) or S dublin whole cells as antigen, was used to measure specific IgG and IgM responses . Antibody responses to LPS were not detected from calves < 12 weeks old inoculated with killed bacterin . Immunoglobulin responses to whole-cell antigen were detected from all age groups of calves inoculated with the same killed Salmonella bacterin . Calves < 11 weeks old are able to produce immunoglobulins to some whole-cell antigens, but are unable to produce anti-LPS immunoglobulins when inoculated with killed Salmonella bacterin . This age-related response to killed Salmonella antigens may account, in part, for increased susceptibility to salmonellosis in calves < 12 weeks old . In comparison to the response for killed antigen, 8 calves given modified-live aromatic-dependent S dublin bacterin at 1 to 3 weeks of age had detectable anti-LPS immunoglobulins after immunization, although the response was not as rapid and was of a lesser magnitude than that of older calves given killed Salmonella bacterin. J R Soc Health, 1992 Oct, 112(5), 212 - 3 Incidence of salmonellosis in local hens' eggs; Camilleri F; Evidence indicates that outbreaks of salmonellosis may be due to infected eggs . This prompted a study on the incidence of salmonella in eggs . This study was done during summer 1991 and 900 eggs were examined in all . None of the eggs examined were found to be infected with salmonella . However, the result obtained should be treated with care and analysed with a critical eye . The result obtained does not imply that local flocks are not infected by salmonella. Pathol Res Pract, 1992 Oct, 188(7), 931 - 41 Mobilization of iron and iron-related proteins in rat spleen after intravenous injection of lipopolysaccharides (LPS); Kumagai T et al.; We used lipopolysaccharide (LPS) to provoke immune responses and observed the changes in the localization of iron and iron-related proteins, such as transferrin receptor, ferritin and hemosiderin in the rat spleen . After intravenous injection of 250 micrograms LPS (salmonella minnesota R595), spleen weight and serum IgM levels increased, cells incorporating 5-bromo-2'-deoxyuridine (BrdU), and transferrin receptor positive cells increased in the peripheral portion of the periarterial lymphoid sheath (PALS), the marginal zone (MZ) and the follicles . Ferritin positive cells increased markedly in the white pulp and stainable iron increased in the marginal metallophils (MM) and in the macrophages in the MZ and the outer PALS . Even in iron deficient rats, a similar change was observed for the localization of iron and iron-related proteins after injection of LPS . After injection of 0.4 mg keyhole limpet hemocyanin (KLH), changes similar to but less pronounced than that in the LPS injected rats were observed for serum IgM levels and for the localization of iron and iron-related proteins . These results showed that the iron in the MM and the macrophages in the white pulp have a dynamic response to immunological challenges and suggested that they play some role in immune responses. Immunol Invest, 1992 Oct, 21(6), 581 - 8 A simple and inexpensive glucose oxidase substrate system for enzyme immunoassay; Blais BW et al.; A simple and inexpensive glucose oxidase substrate system was developed for enzyme immunoassay . This system is based on the formation of a coloured complex between polyvinyl alcohol or starch and iodine produced from iodide in the presence of hydrogen peroxide generated by the glucose oxidase reaction . The rate of iodine production was enhanced by the supplementation of molybdate . In an enzyme immunoassay for anti-Salmonella antibodies using glucose oxidase as the indicator enzyme, the molybdate-enhanced polyvinyl alcohol- and starch-glucose-iodide substrate systems were as sensitive as a conventional glucose oxidase assay system employing horseradish peroxidase as a secondary enzyme and a suitable hydrogen-donating chromogen. Immunology, 1992 Oct, 77(2), 289 - 97 Antigen-presenting characteristics of peritoneal cells of Salmonella enteritidis 11RX-infected mice; Pope M et al.; Investigation of the possibility that infection with intracellular bacterial parasites such as Salmonellae may modulate the function of antigen-presenting cells (APC) revealed no major change in APC function of peritoneal cells (PC) harvested from the peritoneal cavity of mice 1-3 days after intraperitoneal immunization with S . enteritidis 11RX . Analysis of the phenotype of the Salmonella-primed T cells which responded when cultured with PC from either normal or infected mice and Salmonella-antigen showed that only L3T4+ T cells proliferated . This was also true when PC from normal and infected mice were compared for their ability to induce allogeneic responses; both L3T4+ and Lyt-2.2+ T cells were induced to proliferate, with the majority belonging to the class I restricted, Lyt-2.2+ phenotype . Significant levels of alloantigen-specific Lyt-2.2+ cytotoxic T-cell activity were also induced in both types of cultures . However, a minor population of adherent cells which inhibited Salmonella antigen-specific T-cell proliferation in vitro was detected in peritoneal cell suspensions harvested 3 days after intraperitoneal immunization with S . enteritidis 11RX . Further characterization of these peritoneal cells revealed that they also inhibited the induction of in vitro T-cell responses to alloantigens . It is likely that the cells mediating these inhibitory effects belonged to a macrophage-like subset. Acta Paediatr, 1992 Oct, 81(10), 856 - 8 Neonatal Salmonella panama infection with meningitis; Kostiala AA et al.; Three full-term neonates contracted a hospital infection with Salmonella panama derived from the mother of one . Two had bacteraemia and meningitis; one developed a brain abscess and the other recurrent meningitis at two months . The third neonate had gastroenteritis only . Six months later they had developed normally and two were still excreting salmonellae in the stools. J Vet Med Sci, 1992 Oct, 54(5), 845 - 50 The role of 36 megadalton plasmid of Salmonella enteritidis for the pathogenesis in mice; Suzuki S et al.; The pathogenesis associated with the 36 Megadalton (Md) plasmid of Salmonella choleraesuis subsp . choleraesuis serovar Enteritidis (S . Enteritidis) was assessed by using the plasmid-containing strain AL1190, plasmid-cured strain AL1192, and plasmid-reintroduced strain AL1193 . After oral inoculation of strain AL1190 or AL1192 to C57BL/6 mice, mesenteric lymph nodes, spleens, and livers were examined for the numbers of viable bacteria and for the histopathological changes . The numbers of bacteria were greater and histopathological changes were severer in these organs of mice inoculated with strain AL1190, than in those with strain AL1192 . Strains AL1190, AL1192, and AL1193 showed the equivalent survival rate to sera of guinea pig, calf, and pig, and grew equally well under the iron-limiting conditions . These results suggested that the 36 Md plasmid of S . Enteritidis contribute to the spread of the infection beyond small intestines to mesenteric lymph nodes, spleens, and livers, but not to serum resistance or acquisition of iron. Eur J Pediatr Surg, 1992 Oct, 2(5), 301 - 3 Acute acalculous cholecystitis caused by Salmonella typhi in a 6-year-old child; Yulevich A et al.; A rare case of acute acalculous cholecystitis caused by Salmonella typhi in a 6-year-old child is presented . The clinical signs were fulminant, with diffuse peritonitis being suspected . Cholecystostomy and i.v . ceftriaxone proved efficacious and the girl was discharged in less than two weeks . The appropriate literature is reviewed. Nature, 1992 Oct 1, 359(6394), 431 - 3 Probing met repressor-operator recognition in solution; He YY et al.; The three-dimensional crystal structure of the Escherichia coli methionine repressor, MetJ, complexed with a DNA operator fragment is described in an accompanying article . The complex exhibits several novel features of DNA-protein interaction . DNA sequence recognition is achieved largely by hydrogen-bond contacts between the bases and amino-acid side chains located on a beta-ribbon, a mode of recognition previously hypothesized on the basis of modelling of idealized beta-strands and DNA, and mutagenesis of the Salmonella phage P22 repressors Arc and Mnt . The complex comprises a pair of MetJ repressor dimers which bind to adjacent met-box sites on the DNA, and contact each other by means of a pair of antiparallel alpha-helices . Here we assess the importance of these contacts, and also of contacts that would be made between the C-helices of the protein and DNA in a previous model of the complex, by studying mutations aimed at disrupting them . The role of the carboxy-terminal helix face in operator binding was unclear, but we demonstrate that recognition of operator sequences occurs through side chains in the beta-strand motif and that dimer-dimer interactions are required for effective repression. J Trop Med Hyg, 1992 Oct, 95(5), 356 - 7 Typhoid fever and nephrotic syndrome--an unusual association; Karthikeyan G et al.; We report a case of nephrotic syndrome seen in a 9-year-old boy having a significant temporal relationship with culture proven multidrug resistant Salmonella typhi infection . Such an association is quite unusual and probably has not been reported before. J Med Microbiol, 1992 Oct, 37(4), 252 - 7 The use of biochemical fingerprinting, phage typing and antimicrobial-susceptibility testing in the detection of epidemic strains of Salmonella of serotype Typhimurium in Iran; Katouli M et al.; A collection of 86 strains of Salmonella of serotype Typhimurium isolated from children with gastroenteritis in Tehran, Iran was examined for biochemical phenotype, phage type and antibiotic-resistance pattern . Twenty-seven biochemical phenotypes (BPTs), 14 discrete phage types (PTs) and 18 resistotypes (RTs) were identified . Fifty-three strains (62%) belonged to two major and probably related BPTs, whereas the other 33 isolates belonged to less common BPTs . The two predominant BPTs contained 26 strains of the same PT and 23 strains of the same RT . Different PTs and RTs of strains with similar BPT were sometimes observed, possibly reflecting antibiotic pressures in Iran . These results suggest that two major "clones" of Typhimurium strains are particularly common in Iran and, although each method alone adequately detected these and other less common "clones", biochemical fingerprinting provided additional information about relationships among strains. J Med Microbiol, 1992 Oct, 37(4), 245 - 51 Evaluation of the PhP system for biochemical-fingerprint typing of strains of Salmonella of serotype Typhimurium; Katouli M et al.; The Phene Plate (PhP) system of biochemical fingerprinting of bacteria is a computerised typing system, based on quantitative measurements of the kinetics of several biochemical reactions of bacteria grown in liquid medium in microtitration plates . For each isolate tested, it yields a biochemical fingerprint comprising several kinds of quantitative data which are useful for establishing similarities among strains with a personal-computer program . In this study, a set of 16 specific substrates was chosen to differentiate strains of Salmonella of serotype Typhimurium . The system was evaluated for its typability, reproducibility and discriminatory power in tests with a collection of 100 epidemiologically unrelated Typhimurium strains and results were compared with those obtained by phage typing . At an identity level of 0.980, strains were assigned by this method to 51 biochemical phenotypes (BPTs), giving a diversity index of 0.963 and a resolution index of 0.210 . In contrast, 24 phage types (PTs) were identified among these isolates (a diversity index of 0.901) . The combined use of biochemical fingerprinting by the PhP system and phage typing discriminated 82 phenotypes (a diversity index of 0.994) . Stability of markers in each of the methods was also evaluated after subculture of 20 strains for 21 consecutive days . Only nine biochemical reactions were found that were subject to small, but measurable, changes for at least one isolate . These changes slightly decreased the mean similarity coefficients among strains but the overall BPTs of the strains showed changes in four strains (20%) . In contrast, eight strains (40%) showed changes in their PTs after this treatment . It is concluded that the PhP system is a highly discriminatory and reproducible method for typing Typhimurium strains . It is easy to perform, and may be used alone or in combination with phage typing in epidemiological studies of Typhimurium strains. J Lab Clin Med, 1992 Oct, 120(4), 574 - 88 Monoclonal antibody to tumor necrosis factor--alpha prevents lethal endotoxin sepsis in adult rhesus monkeys; Fiedler VB et al.; In a rhesus monkey endotoxin sepsis model established by intravenous administration of 300 mg/kg D-galactosamine and 0.1 microgram/kg lipopolysaccharide from Salmonella abortus equi, hemodynamic, respiratory, metabolic and hematologic variables; levels of blood gases; monkey leukocyte elastase levels, and blood plasma concentrations of tumor necrosis factor--alpha (TNF) were monitored for 6 hours after administration, and again after 24 hours . Thirty minutes after administration of lipopolysaccharide, either 15 mg/kg anti-TNF monoclonal antibody (MoAB; n = 6) or vehicle placebo (saline solution; n = 4) were given intravenously . During this short-term experiment the organ functions were not different between the treatment groups . However, anti-TNF MoAb afforded morphologic protection from heart, lung, liver, and kidney damage after lipopolysaccharide challenge . Coagulation responses (platelet count and levels of fibrinogen, antithrombin III, and thrombin-antithrombin III complex) were smaller in anti-TNF MoAB-treated monkeys . Plasma TNF levels (WEHI cell cytotoxicity assay) reached a peak (350 pg/ml) 60 minutes after lipopolysaccharide administration in vehicle control subjects but no TNF was detected in the anti-TNF MoAB-treated monkeys . All control animals died 67 +/- 30 hours after lipopolysaccharide administration from multiorgan failure . On the contrary, all anti-TNF MoAB-treated animals survived 14 days (p > 0.005 vs placebo group mortality) . Thus in short-term monkey experiments our study indicates protection against lipopolysaccharide-induced endotoxin sepsis by anti-TNF MoAB, which may have clinical relevance for the treatment of human septicemia. J Clin Microbiol, 1992 Oct, 30(10), 2560 - 6 Comparison of four different enzyme-linked immunosorbent assays for serological diagnosis of Salmonella enteritidis infections in experimentally infected chickens; van Zijderveld FG et al.; The program for the eradication of Salmonella enteritidis from chickens in The Netherlands is based on bacteriological examination of breeding flocks . There is a great need for a specific and sensitive serological screening test . For that purpose, we developed four different enzyme-linked immunosorbent assays (ELISAs), i.e., an indirect ELISA with S . enteritidis flagellin, an indirect ELISA with S . enteritidis lipopolysaccharide, a double-antibody sandwich blocking ELISA that uses monoclonal antibodies against S . enteritidis flagellin (GM-DAS blocking ELISA), and a double-antibody sandwich ELISA that uses monoclonal antibodies against S . enteritidis lipopolysaccharide . In the present study, we compare the results of those ELISAs with sera from experimentally infected 1-day-old chickens and with sera and eggs from experimentally infected laying hens . Experimental infections were induced with strains of S . enteritidis phage types 1 and 2, S . typhimurium, and S . panama . Sera were collected up to days 44 and 39 after infection from 1-day-old chickens and laying hens, respectively . Only the GM-DAS blocking ELISA was able to discriminate between S . enteritidis infections and infections with the other serotypes . This ELISA had both a sensitivity and a specificity of 100% for all serum samples from experimentally infected chickens . A field study is in progress to evaluate whether this test can be implemented in the Dutch S . enteritidis eradication program. J Bacteriol, 1992 Oct, 174(20), 6418 - 23 Characterization of translation termination mutations in the spv operon of the Salmonella virulence plasmid pSDL2; Roudier C et al.; The spv region of the Salmonella virulence plasmids consists of five genes located on an 8-kb fragment previously shown to be essential for virulence in mice . Four structural genes, spvABCD, form an operon that is transcriptionally activated by the spvR