Vet Microbiol, 1996 Jul, 51(1-2), 55 - 68 Equine herpesvirus type 2 (EHV-2) as a predisposing factor for Rhodococcus equi pneumonia in foals: prevention of the bifactorial disease with EHV-2 immunostimulating complexes; Nordengrahn A et al.; Equine herpesvirus type 2 (EHV-2), a member of the Gammaherpesvirinae subfamily, was studied in a two-phase respiratory disease complex of young foals as a predisposing factor for the secondary bacterial invasion of lungs with Rhodococcus equi (R . equi) . Foals were immunized against EHV-2 on a farm where R . equi pneumonia regularly occurred during the last years . The immunizations were performed by using a subunit vaccine which selectively presents envelope glycoproteins of EHV-2 in a multimeric form of immunostimulating complexes (iscoms) . The etiological role of EHV-2 was estimated by observing the occurrence of the respiratory disease complex in groups of foals immunized against the virus, in comparison to non-immunized controls . The immunization trials of young animals revealed that the iscom subunit vaccine formulation is able to overcome the interference of maternal antibodies . Active immunization of foals with a single dose of the iscoms provided a certain degree of protection, while two injections of iscoms yielded complete protection against the disease complex in the majority of the treated animals, by preventing the manifestation of R . equi pneumonia . The present findings strongly support the hypothesis that EHV-2 is a predisposing factor for the R . equi invasion of the respiratory tract . The EHV-2 iscom formulation provides highly specific and effective means to prevent the disease complex. Can J Vet Res, 1996 Jul, 60(3), 186 - 92 Role of CD4+, CD8+ and double negative T-cells in the protection of SCID/beige mice against respiratory challenge with Rhodococcus equi; Ross TL et al.; To evaluate the contributions of T-lymphocyte subsets in pulmonary immunity against Rhodococcus equi, C.B-17 SCID/beige mice were adoptively transferred with splenic lymphocytes from congenic BALB/c mice previously infected with R . equi . Spleen cells were enriched for either CD4+ or CD8+ populations before inoculation, Flow cytometry showed that each enriched population contained less than 0.5% cross contamination . Groups of adoptively transferred SCID/beige mice were sacrificed 6 and 13 d after intranasal infection with R . equi . Bacterial clearance was measured in the lungs, liver and spleen . Lesion development was assessed by gross and histopathological score and the fate of transferred cells assessed by flow cytometry and by immunohistochemistry . SCID/beige mice receiving either CD4+ or CD8+ T-cells were able to clear the infection better than control mice . On d 6 post-infection, bacterial numbers were significantly lower in the lungs of CD4+ transferred mice as compared to CD8+ mice . By d 13, both groups had cleared R . equi from all organs . CD4+ cells were however identified in the lung and spleen of CD8+ recipients at d 13 making conclusions about the role of CD8+ cells in R . equi clearance impossible . By contrast, no significant increases in CD8+ lymphocytes were observed in the organs of CD4+ recipients . All mice developed suppurative bronchopneumonia but lesions were most severe in the CD4+ group . Immunohistochemistry and flow cytometry confirmed that CD4+ and CD8+ cells had migrated to the lungs of adoptively transferred mice . Serum antibody against R, equi was not detected by ELISA in the recipients . SCID/beige mice receiving CD4-CD8- cells were unable to clear R . equi . The study supports the suggestion that CD4+ cells have a central role in R . equi clearance in mice. Int J Syst Bacteriol, 1996 Jul, 46(3), 832 - 4 Taxonomic note: a proposal for reviewing the interpretation of the CAMP reaction between Listeria monocytogenes and Rhodococcus equi; Fernandez-Garayzabal JF et al.; The discrepancies between the current description of the CAMP test between Listeria monocytogenes and Rhodococcus equi in the latest edition of Bergey's Manual of Determinative Bacteriology (L . monocytogenes is described as CAMP test negative with R . equi) and routine findings (positive reactions are usually described in many laboratories) make it advisable to review the current interpretation of the CAMP test to avoid confusion among people working in microbiological laboratories . Overall, 98.4% of the L . monocytogenes strains examined in this study, regardless of their source or the intensity of their hemolytic activity, displayed a synergic hemolytic reaction (CAMP phenomenon) with R . equi, indicating that L . monocytogenes can generally be considered CAMP positive with R . equi . We propose that L . monocytogenes, together with Listeria ivanovii, should be considered CAMP test positive with R . equi (circular or racket and semicircular or shovel shapes, respectively). Immunology, 1996 Jul, 88(3), 394 - 9 Reciprocal action of interferon-gamma and interleukin-4 promotes granulomatous inflammation induced by Rhodococcus aurantiacus in mice; Asano M et al.; An intravenous injection of Rhodococcus aurantiacus to mice causes granulomatous inflammation dependent on endogenous interferon-gamma (IFN-gamma) . The present study examined the role of endogenous interleukin-4 (IL-4) on granulomatous inflammation . Endogenous IL-4 in the spleen extracts was not detected during the phase of granuloma formation by enzyme-linked immunosorbent assay (ELISA) . However, IL-4 protein level was elevated during the phase of granuloma regression . IL-4 mRNA expression in the livers and spleens was also elevated during the phase of granuloma regression . In addition, IL-4 levels during the phase of granuloma formation were increased by treatment with anti-IFN-gamma monoclonal antibody (mAb), suggesting that endogenous IFN-gamma might inhibit IL-4 production during the phase of granuloma formation . Administration of anti-IL-4 mAb on weeks 3 and 4 after the inoculation inhibited the regression of granulomas and augumented IFN-gamma level at 5 weeks . Endogenous IFN-gamma was produced by CD4+ T cells during the phase of granuloma regression and endogenous IL-4 was produced by both CD4+ and CD8+ T cells . These findings suggest that during the phase of granuloma formation endogenous IL-4 might be inhibited by IFN-gamma, while during the phase of granuloma regression endogenous IL-4 might play a crucial role in the reduction of granulomas and IFN-gamma production. Curr Microbiol, 1996 Jul, 33(1), 26 - 30 Identification of a Rhodococcus gene cluster encoding a homolog of the 17-kDa antigen of Brucella and a putative regulatory protein of the AsnC-Lrp family; De Mot R et al.; By sequence analysis, a gene encoding a homolog of the 17-kDa protein antigen of the Gram-negative pathogen Brucella abortus (Hemmen et al., Clin Diagn Lab Immunol 2: 263, 1995) was identified in the nocardioform actinomycete Rhodococcus sp . NI86/21 . Database searching also revealed a partial human cDNA sequence for a putative eukaryotic homolog of this presumptive Brucella-specific protein . These proteins display a low but significant level of similarity with lumazine synthases involved in bacterial riboflavin biosynthesis . In the upstream region, a Rhodococcus gene for a putative regulatory protein of the AsnC family is located. J Biol Chem, 1996 Jun 28, 271(26), 15796 - 802 A novel gene cluster including the Rhodococcus rhodochrous J1 nhlBA genes encoding a low molecular mass nitrile hydratase (L-NHase) induced by its reaction product; Komeda H et al.; The 3.5 kilobases (kb) of the 5'-upstream region from nhlBA encoding a cobalt-containing low molecular mass nitrile hydratase (L-NHase) from Rhodococcus rhodochrous J1 was found to be required for the amide-dependent expression of nhlBA in experiments using a Rhodococcus transformation system . Sequence analysis of the 3.5-kb fragment revealed the presence of two open reading frames (nhlD and nhlC) in this fragment . NhlD has similarity to regulators MerR, CadC, and ArsR . NhlC has similarity to the regulators AmiC, for the expression of an aliphatic amidase from Pseudomonas aeruginosa, and NhhC, for the expression of a high molecular mass nitrile hydratase from R . rhodochrous J1 . Assays of NHase activity of transformants carrying nhlD deletion or nhlC deletion mutations suggest a negative regulatory role for nhlD and a positive regulatory role for nhlC in the process of the L-NHase formation . Assays of NHase and amidase activities and Western blot analyses of each Rhodococcus transformant carrying various deletion plasmids, have shown that nhlBA and amdA encoding an amidase, which is located 1.9 kb downstream of nhlBA, were regulated in the same manner . These findings present the genetic evidence for a novel gene cluster controlling the expression of L-NHase, which is induced by the reaction product (amide) in the "practical microorganism" R . rhodochrous J1. Aust Vet J, 1996 Jun, 73(6), 201 - 6 The incidence and consequences of failure of passive transfer of immunity on a thoroughbred breeding farm; Raidal SL; Circulating IgG concentration was determined between 12 and 24 hours after birth for 323 foals born on a Thoroughbred breeding farm over 3 consecutive years . The incidence of failure of passive transfer (FPT) of maternal immunoglobulins (foal circulating IgG concentration < 8 g/L) was found to be 9.6% . Foals born late in the season (October to December) were found to be at increased risk for the development of FPT . The degree of assistance required at parturition and the presence of a periparturient problem in the mare or foal also significantly influenced the subsequent incidence of FPT . Passive immune status significantly influenced the likelihood of foals developing septic illness (joint ill, septicaemia, pneumonia) in the first month of life, but had no significant effect on the development of diarrhoea or Rhodococcus equi pneumonia . The results of the current study support the value of routine monitoring of passive immune status and the early speculative treatment of foals considered to be at risk for the development of FPT. Biodegradation, 1996 Jun, 7(3), 249 - 55 Biodegradation of 4-nitroanisole by two Rhodococcus spp; Schafer A et al.; Two Rhodococcus strains, R . opacus strain AS2 and R . erythropolis strain AS3, that were able to use 4-nitroanisole as the sole source of carbon and energy, were isolated from environmental samples . The first step of the degradation involved the O-demethylation of 4-nitroanisole to 4-nitrophenol which accumulated transiently in the medium during growth . Oxygen uptake experiments indicated the transformation of 4-nitrophenol to 4-nitrocatechol and 1,2,4-trihydroxybenzene prior to ring cleavage and then subsequent mineralization . The nitro group was removed as nitrite, which accumulated in the medium in stoichiometric amounts . In R . opacus strain AS2 small amounts of hydroquinone were produced by a side reaction, but were not further degraded. Arch Microbiol, 1996 Jun, 165(6), 377 - 86 Formation of intracytoplasmic lipid inclusions by Rhodococcus opacus strain PD630; Alvarez HM et al.; An oleaginous hydrocarbon-degrading Rhodococcus opacus strain (PD630) was isolated from a soil sample . The cells were able to grow on a variety of substrates and to produce large amounts of three different types of intracellular inclusions during growth on alkanes, phenylalkanes, or non-hydrocarbon substrates . Electron microscopy revealed large numbers of electron-transparent inclusions with a sphere-like structure . In addition, electron-dense inclusions representing polyphosphate and electron-transparent inclusions with an elongated disc-shaped morphology occurred in small amounts . The electron-transparent inclusions of alkane- or gluconate-grown cells were composed of neutral lipids (98%, w/w), phospholipids (1.2%, w/w), and protein (0.8%, w/w) . The major component of the cellular inclusions was triacylglycerols; minor amounts of diacylglycerols and probably also some free fatty acids were also present . Free fatty acids and/or fatty acids in acylglycerols in cells of R . opacus amounted up to 76 or 87% of the cellular dry weight in gluconate- or olive-oil-grown cells, respectively . The fatty acid composition of the inclusions depended on the substrate used for cultivation . In cells cultivated on n-alkanes, the composition of the fatty acids was related to the substrate, and intermediates of the beta-oxidation pathway, such as hexadecanoic or pentadecanoic acid, were among the acylglycerols . Hexadecanoic acid was also the major fatty acid (up 36% of total fatty acids) occurring in the lipid inclusions of gluconate-grown cells . This indicated that strain PD630 utilized beta-oxidation and de novo fatty acid biosynthesis for the synthesis of storage lipids . Inclusions isolated from phenyldecane-grown cells contained mainly the non-modified substrate and phenylalkanoic acids derived from the hydrocarbon oxidation, such as phenyldecanoic acid, phenyloctanoic acid, and phenylhexanoic acid, and approximately 5% (w/w) of diacylglycerols . The lipid inclusions seemed to have definite structures, probably with membranes at their surfaces, which allow them to maintain their shape, and with some associated proteins, probably involved in the inclusion formation. J Bacteriol, 1996 Jun, 178(12), 3501 - 7 Purification and properties of an amidase from Rhodococcus erythropolis MP50 which enantioselectively hydrolyzes 2-arylpropionamides; Hirrlinger B et al.; An enantioselective amidase from Rhodococcus erythropolis MP50 was purified to homogeneity . The enzyme has a molecular weight of about 480,000 and is composed of identical subunits with molecular weights of about 61,000 . The NH2-terminal amino acid sequence was significantly different from previously published sequences of bacterial amidases . The purified amidase hydrolyzed a wide range of aliphatic and aromatic amides, The highest enzyme activities were found with amides carrying hydrophobic residues, such as pentyl or naphthoyl . The purified enzyme converted racemic 2-phenylpropionamide, naproxen amide {2-(6-methoxy-2-naphthyl) propionamide}, and ketoprofen amide {2-(3'-benzoylphenyl)propionamide} to the corresponding S-acids with an enantiomeric excess of >99% and an almost 50% conversion of the racemic amides . The enzyme also hydrolyzed different alpha-amino amides but without significant enantioselectivity. Gene, 1996 May 24, 171(1), 53 - 7 Location and sequence analysis of a 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase-encoding gene (bpdF) of the biphenyl/polychlorinated biphenyl degradation pathway in Rhodococcus sp . M5; Lau PC et al.; The 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate (HOPD) hydrolase-encoding gene (bpdF) in the biphenyl (BP)/polychlorinated biphenyl (PCB)-degrading bacterium, Rhodococcus sp . M5 (M5), was found to be located within a 4.5-kb HindIII-BamHI genomic DNA that was 5.4 kb downstream from the bpdC1C2BADE gene cluster . The deduced amino acid (aa) sequence of bpdF revealed that the hydrolase contains 297 aa (32679 Da) that was verified by expression in the Escherichia coli T7 RNA polymerase/promoter system . Unlike previously known HOPD hydrolases, the aa sequence of BpdF appears unique . Interestingly, all HOPD hydrolases and related proteins from the phenol and toluene/xylene degradation pathways, were found to have a bias in the codon usage in the catalytic Ser within the conserved VGNS(M/F)GG motif. Zentralbl Veterinarmed B, 1996 May, 43(3), 147 - 53 Relationship between haemagglutination and HeLa-cell adherence of Rhodococcus equi; Bern D et al.; In this study, 45 Rhodococcus equi isolates from animals and humans were identified by the Api Coryne system, and serologically with monospecific antisera against capsular types 1-7, with serotypes 1 and 2 predominating . Regardless of serotype, 14 out of 31 isolates from animals and one of 14 isolates from humans expressed 15-17-kD virulence-associated proteins . In hexadecane adherence studies, serotype 2 isolates generally displayed hydrophobic surfaces . In addition, isolates of serotype 1 generally haemagglutinated erythrocytes from rabbits . Neither property appeared to be related to the occurrence of the virulence-associated proteins . By contrast, the haemagglutination reaction correlated significantly with the adherence of the bacteria to HeLa cells . This adhesion might serve as additional marker of virulence among isolates of R . equi and might be useful in epidemiological studies. J Struct Biol, 1996 May, 116(3), 438 - 42 2-D Crystallization of the Rhodococcus 20S Proteasome Aoyama K, Zuhl F, Tamura T, Baumeister W. The 2D crystallization method using a liquid-liquid interface has been applied to the Rhodococcus 20S proteasome . Two types of ordered arrays were obtained, both large enough for high-resolution analysis . The first one is a hexagonal close-packed array, whereas the second one has fourfold symmetry . By image analysis based on a real space correlation averaging technique, the close-packed array was found to be hexagonally packed but the molecules had complete rotational freedom . The fourfold array is, however, a true crystal with p4 symmetry . Lattice constants are a = b = 20.0 nm and the unit cell of this crystal contains two proteasomes . The diffraction pattern computed from the original picture shows the spots up to (4.5) that correspond to 3.1 nm resolution . After applying an unbending procedure, the diffraction pattern shows spots extending to 1.8 nm resolution. Appl Microbiol Biotechnol, 1996 May, 45(4), 556 - 61 The microbiological fate of polycyclic aromatic hydrocarbons: carbon and oxygen balances for bacterial degradation of model compounds; Bouchez M et al.; A series of pure bacterial strains belonging mainly to the Rhodococcus and Pseudomonas genera were grown on one of the following polycyclic aromatic hydrocarbons (PAH) supplied as sole carbon and energy source; naphthalene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene . In each case, a quantitative evaluation of the carbon repartition of the PAH degraded into CO2, biomass and water-soluble metabolites was carried out . In addition, the kinetics of oxygen consumption and of water-soluble metabolite accumulation during PAH biodegradation was followed with respirometric equipment . Satisfactory carbon balances were obtained and the data correlated well with oxygen consumption values . The results show that growth on PAH presents high mineralization yields (from 56% to 77% of carbon) and sizeable production of biomass (from 16% to 35% of carbon) and limited but significant accumulation of metabolites (from 5% to 23% of carbon) . The mineralization yields were higher and biomass yields lower in the case of higher PAH . Some differences between strains were also observed. Vet Pathol, 1996 May, 33(3), 341 - 3 Immunohistochemical detection of virulence-associated antigens of Rhodococcus equi in pulmonary lesions of foals; Madarame H et al.; Rhodococcus equi was isolated from the lungs of six foals with bronchopneumonia . All isolates expressed 15-17-kd antigens by immunoblot analysis and contained a virulence-associated plasmid of 85 or 90 kb . Immunohistochemically, R . equi from all pulmonary lesions showed the expression of 15-17-kd antigens mainly in the phagocytic cells . The specific monoclonal antibody to 15-17-kd antigens of R . equi (MAb 10G5) may be an aid in the diagnosis of R . equi-induced pneumonia. Mod Pathol, 1996 May, 9(5), 476 - 83 Pulmonary malakoplakia in acquired immunodeficiency syndrome: an ultrastructural study of morphogenesis of Michaelis-Gutmann bodies; Yuoh G et al.; Malakoplakia is an unusual inflammatory reaction to a variety of infections, characterized by the accumulation of macrophages containing the target-like calcospherites, the Michaelis-Gutmann body (MGB) . We report three patients with acquired immunodeficiency syndrome with pulmonary malakoplakia associated with Rhodococcus equi infection; two patients were diagnosed at autopsy and one by examination of a transbronchial biopsy specimen . All three patients had pulmonary bacterial cultures and light and electron microscopic examination . The patients were 33-, 41-, and 43-year old men, human immunodeficiency virus-positive for 2, 6, 8 years, respectively . The two patients diagnosed at autopsy had cavitary lesions, and the patient diagnosed by biopsy specimen had nodular lesions on chest radiographs . Histologically, the lungs had well-circumscribed areas of infiltration with benign macrophages with granular cytoplasm, scattered MGBs, and numerous gram-positive coccobacilli . Electron microscopic examination showed intracellular coccobacilli, from 990 X 702 to 972 X 648 nm in diameter, with thick, homogenous cell walls, trilaminar cytoplasmic membranes, and dense cytoplasm with from one to five vacuoles . Electron microscopic studies showed that the bacteria within the pulmonary macrophages had thicker cell walls, less prominent nucleoid areas, and more vacuoles than the bacteria in cultures from the sputum and blood . The mature MGB ultrastructurally had a concentric, trilaminate structure with central mineralized core and was without recognizable bacterial forms . Early MGBs, however, consisted of a circular, electron-dense core containing bacteria, ultrastructurally similar to the R . equi seen in the culture . Pulmonary malakoplakia in patients with the acquired immunodeficiency syndrome might thus represent an acquired macrophage dysfunction of the intracellular digestion of phagocytized bacteria . The bacteria within the macrophages, however, seemed to have thicker cell walls compared with those in culture, and thus might be protected from enzyme digestion . It seems that MGBs are formed around the undigested bacteria as an alternative pathway for bacterial destruction, because R . equi was identified within the cores of early MGBs but not the mature or late stage MGBs. Proc Natl Acad Sci U S A, 1996 Apr 30, 93(9), 4267 - 72 Characterization of the gene cluster of high-molecular-mass nitrile hydratase (H-NHase) induced by its reaction product in Rhodococcus rhodochrous J1; Komeda H et al.; The 4.6-kb region 5'-upstream from the gene encoding a cobalt-containing and amide-induced high molecular mass-nitrile hydratase (H-NHase) from Rhodococcus rhodochrous J1 was found to be required for the expression of the H-NHase gene with a host-vector system in a Rhodococcus strain . Sequence analysis has revealed that there are at least five open reading frames (H-ORF1 approximately 5) in addition to H-NHase alpha- and beta-subunit genes . Deletion of H-ORF1 and H-ORF2 resulted in decrease of NHase activity, suggesting a positive regulatory role of both ORFs in the expression of the H-NHase gene . H-ORF1 showed significant similarity to a regulatory protein, AmiC, which is involved in regulation of amidase expression by binding an inducer amide in Pseudomonas aeruginosa . H-ORF4, which has been found to be uninvolved in regulation of H-NHase expression by enzyme assay for its deletion transformant and Northern blot analysis for R . rhodochrous J1, showed high similarity to transposases from insertion sequences of several bacteria . Determination of H-NHase activity and H-NHase mRNA levels in R . rhodochrous J1 has indicated that the expression of the H-NHase gene is regulated by an amide at the transcriptional level . These findings suggest the participation of H-ORF4 (IS1164) in the organization of the H-NHase gene cluster and the involvement of H-ORF1 in unusual induction mechanism, in which H-NHase is formed by amides (the products in the NHase reaction), but not by nitriles (the substrates). Biochem Biophys Res Commun, 1996 Apr 5, 221(1), 146 - 50 Location of the non-heme iron center on the alpha subunit of photoreactive nitrile hydratase from Rhodococcus sp . N-771; Odaka M et al.; Nitrile hydratase (NHase) from Rhodococcus sp . N-771, which possesses a non-heme iron center binding nitric oxide (NO), is activated by light irradiation . To localize the iron center in the protein, we quantified Fe atoms and performed FTIR measurements of the isolated alpha and beta subunits . The native NHase and the isolated alpha subunit contained about 1.0 and 0.8 mol Fe per mol protein, respectively, whereas the beta subunit contained only a trace of Fe . An NO stretching band was observed at 1852 cm-1 in the FTIR spectrum of the alpha subunit, but not in that of the beta subunit . Upon light irradiation of the alpha subunit, the affinity of the Fe atom decreased and the NO band disappeared from the FTIR spectrum . These observations indicate that the non-heme iron center, which is responsible for the photoreaction, is present in the alpha subunit. J Clin Microbiol, 1996 Apr, 34(4), 1034 - 7 Identification of intermediately virulent Rhodococcus equi isolates from pigs; Takai S et al.; We recently reported the existence of Rhodococcus equi isolates with at least three virulence levels, isolated from AIDS patients: virulent R . equi having 15- to 17-kDa antigens that kills mice with 10(6) cells, intermediately virulent R . equi having a 20-kDa antigen that kills mice with 10(7) cells, and avirulent R . equi that does not kill mice with 10(8) cells or more (S . Takai, Y . Imai, N . Fukunaga, Y . Uchida, K . Kamisawa, Y . Sasaki, S . Tsubaki, and T . Sekizaki, J . Infect . Dis . 172:1306-1311, 1995) . Virulent R . equi having the 15- to 17-kDa antigens has been isolated frequently from horses and their environment, but the source of intermediately virulent R . equi having the 20-kDa antigen is poorly understood . There are many reports of the isolation of R . equi from the lymph nodes of pigs with and without lesions resembling those of tuberculosis . Therefore, we analyzed antigens of R . equi isolates from the submaxillary lymph nodes of pigs by immunoblotting with monoclonal antibodies against these virulence-associated antigens . Immunoblots of whole-cell antigen preparations of R . equi pig isolates revealed the presence of the 20-kDa antigen in almost all the pig isolates studied, and these isolates were intermediately virulent for mice . We also demonstrated that the expression of the 20-kDa antigen and its pathogenicity in mice were associated strongly with the presence of five large, distinct plasmids of 70 to 95 kb; two of the five plasmids from pig isolates were the same sizes as those from human isolates . These results suggest that R . equi having the 20-kDa antigen exists in the submaxillary lymph nodes of pigs and that the source of infection in some human cases might be associated with pigs and their environment. AIDS, 1996 Apr, 10(4), 359 - 62 Rhodococcus equi infection in HIV-infected patients; Donisi A et al.; OBJECTIVE: To report clinical and microbiological features and response to treatment in HIV patients with Rhodococcus equi infection . DESIGN: Retrospective study . SETTING: Inpatients admitted to two Infectious Diseases Departments in a community-based hospital . PATIENTS: A total of 12 HIV-positive patients with R . equi infection . MAIN OUTCOME MEASURES: Clinical status, radiological finding, microbiological, haematochemical and immunological tests, and response to treatment . RESULTS: Twelve patients (11 men, six injecting drug users) were diagnosed with R . equi infection . Fever and cough were the principal clinical signs on presentation . Mean CD4+ count at the time of diagnosis was 47.67 x 10(6)/l (SD, 49.2 x 10(6)/l) . In 58.3% of the cases the diagnosis of R . equi infection followed the appearance of an AIDS-defining illness . The most frequent radiological findings were cavitary lesions (41.7%) and lung consolidation (33.3%) . In 83% of cases, R . equi was isolated from blood and in 33.3% cases from sputum . Test of chemosensitivity showed sensitivity to vancomycin (100%), teicoplanin (100%), ceftriaxone (80%), erythromycin (71%) and ciprofloxacin (66%) . Clinical response alone with the disappearance of the presenting signs was observed in nine of the 12 cases (75%); complete response was observed in two cases . Seven patients died with a mortality rate of 58.3% and a mean survival of 5.75 months (SD, 6.48 x 10(6)/l) . CONCLUSIONS: R . equi should be considered in the differential diagnosis of pulmonary of disseminated infections in patients with HIV infection . Blood culture may be the most sensitive means of diagnosis . Other studies are needed to determine the most effective choice and duration of antibiotic therapy. Zentralbl Veterinarmed B, 1996 Apr, 43(2), 97 - 107 Blastogenic response of lymphocytes from foals infected with Rhodococcus equi; Sanada Y et al.; The blastogenic response of lymphocytes from 16 newborn foals naturally infected with Rhodococcus equi was investigated, in order to evaluate the relationship between R . equi infection and depressed host response . Naturally infected foals showed evidence of R . equi infection at 5-6 weeks of age, as determined by clinical, haematological, bacteriological and serological methods . The blastogenic response of lymphocytes against phytohaemagglutinin was significantly depressed (stimulation index < 1.80; P < 0.01, P < 0.05) in R . equi-infected foals at 5-6 weeks of age compared with those of control foals . Serum IgG concentration decreased rapidly after foals reached 1 week of age, and minimum levels of IgG were observed at 5-7 weeks of age in R . equi-infected foals . This study suggests that the onset of R . equi infection may be associated with the depressed immune function of naturally infected foals during the first 5-6 weeks after birth. J Bacteriol, 1996 Apr, 178(8), 2397 - 401 Physical, biochemical, and immunological characterization of a thermostable amidase from Klebsiella pneumoniae NCTR 1; Nawaz MS et al.; An amidase capable of degrading acrylamide and aliphatic amides was purified to apparent homogeneity from Klebsiella pneumoniae NCTR 1 . The enzyme is a monomer with an apparent molecular weight of 62,000 . The pH and temperature optima of the enzyme were 7.0 and 65 degrees C, respectively . The purified amidase contained 11 5,5-dithiobis(2-nitrobenzoate) (DTNB)-titratable sulfhydryl (SH) groups . In the native enzyme 1.0 SH group readily reacted with DTNB with no detectable loss of activity . Titration of the next 3.0 SH groups with DTNB resulted in a loss of activity of more than 70% . The remaining seven inaccessible SH groups could be titrated only in the presence of 8 M guanidine hydrochloride . Titration of SH groups was strongly inhibited by carboxymethylation and KMnO4, suggesting the presence of SH groups at the active site(s) . Inductively coupled plasma-atomic emission spectrometry analysis indicated that the native amidase contains 0.33 mol of cobalt and 0.33 mol of iron per mol of the native enzyme . Polyclonal antiserum against K . pneumoniae amidase was raised in rabbits, and immunochemical comparisons were made with amidases from Rhodococcus sp., Mycobacterium smegmatis, Pseudomonas chlororaphis B23, and Methylophilus methylotrophus . The antiserum immunoprecipitated and immunoreacted with the amidases of K . pneumoniae and P . chlororaphis B23 . The antiserum failed to immunoreact or immunoprecipitate with other amidases. Infect Immun, 1996 Apr, 64(4), 1126 - 32 Transfer of a CD4+ Th1 cell line to nude mice effects clearance of Rhodococcus equi from the lung; Kanaly ST et al.; Rhodococcus equi, and intracellular respiratory pathogen, causes sever e granulomatous pneumonia in humans with AIDS and in young horses . Pulmonary clearance of R . equi requires functional CD4+ T cells and gamma interferon (IFN-gamma) expression from bronchial lymph node cells . The purpose of this study was to investigate whether R . equi-specific CD4+ Th1 cells could effect clearance of R . equi from the lung . Adoptive transfer of a clearance of R . equi from the lungs . In contrast, mice transfused with a R . equi-specific CD4+ Th2 cell line expressed interleukin-4 but not IFN-gamma mRNA, failed to clear pulmonary infection, and developed granulomas in the lung . Control mice, which did not receive cells, did not produce IFN-gamma or interleukin-4 and developed small pulmonary granulomas . These results clearly show that a Th1 response is sufficient to effect pulmonary clearance of R . equi. Appl Microbiol Biotechnol, 1996 Mar, 45(1-2), 217 - 23 Simultaneous utilization of pyridine and fructose by Rhodococcus opacus UFZ B 408 without an external nitrogen source; Brinkmann U et al.; A bacterium classified as Rhodococcus opacus, which is able to use pyridine (a potentially growth-inhibiting substrate) as its sole source of carbon, energy and nitrogen, was isolated . In a carbon-limited chemostat culture, the kinetics was determined for growth on both pyridine and a mixture of pyridine and fructose (9 mM/22.15 mM) . With growth on pyridine, stable steady states were achieved up to dilution rates of about 0.1 h-1 . A further increase in the dilution rate resulted in the progressive accumulation of pyridine in the culture liquid and the cells were washed out . The maximum specific growth rate (mu max = 0.23 h-1) and the Ks value (0.22 mM) for growth on pyridine were determined from the residual pyridine concentrations measured within the range of stable steady states . With growth on the substrate mixture, the specific pyridine consumption rates and the residual pyridine concentrations were lower at similar dilution rates than with growth on pyridine alone, and stable steady states were established at dilution rates of up to 0.13 h-1 . The maximum pyridine degradation rate was enhanced to 270 mg pyridine l-1 h-1 compared to 210 mg pyridine l-1 h-1 with growth on pyridine as a single substrate . An external nitrogen source did not need to be added in the case of growth on the substrate mixture . Fructose was assimilated by means of ammonium released from pyridine . Analysis of the nitrogen balance furnished proof that pyridine is an energy-deficient substrate; pyridine was assimilated and dissimilated at a ratio of 1 mol/0.67 mol respectively . The resulting yield coefficient was about 0.55 g dry weight/g pyridine . Moreover, it was demonstrated that, in regard to the biologically usable energy, 1 mol pyridine corresponds to 0.43 mol fructose. Can J Microbiol, 1996 Mar, 42(3), 289 - 94 Growth of rhodococcus S1 on anthracene; Tongpim S et al.; Three slow-growing bacteria were isolated from a mixed culture enriched for growth on anthracene, using creosote-contaminated soil as the inoculum . Organisms were shown to use anthracene by the production of a clear zone around the colony after a mineral salts agar plate was sprayed with anthracene . All three bacteria were nonmotile, nonsporulating, gram-positive rods and stained acid-fast . Physiological and biochemical tests, GC content, and cell wall lipid patterns of whole cell methanolysates indicated that they belonged to the Nocardia-Mycobacterium-Rhodococcus group . On the basis of these characteristics and pyrolysis gas chromatography, they were assigned to the genus Rhodococcus . Growth of the isolates was slow on crystalline anthracene, giving a doubling time of 1.5-3 days, and they grew mainly on the crystal surface . When anthracene was supplied by precipitation from a solvent, doubling time was reduced to 1 day . All three isolates mineralized anthracene but not phenanthrene or naphthalene, nor could they grow on naphthalene, phenanthrene, fluorene, fluoranthene, acenaphthene, pyrene, chrysene, or naphthacene as sole carbon source . One isolate, Rhodococcus S1, was able to use 2-methylanthracene or 2-chloroanthracene as carbon source but not 1- or 9-substituted analogs . These results suggest that the initial enzyme attacking anthracene in these isolates has a narrow substrate specificity. Lett Appl Microbiol, 1996 Mar, 22(3), 249 - 52 Cholesterol oxidase from Rhodococcus equi is likely the major factor involved in the cooperative lytic process (CAMP reaction) with Listeria monocytogenes; Fernanandez-Garayzabal JF et al.; The CAMP reaction between Listeria monocytogenes and Rhodococcus equi was studied by a diffusion assay . Listeria monocytogenes displayed identical cooperative haemolytic effect with supernatant cultures of R . equi or with commercial cholesterol oxidase (COX) . This result, even with enzymes of different sources (commercial COX is obtained from Pseudomonas spp.) suggests that this enzyme secreted by R . equi has a crucial role in the synergistic haemolytic (CAMP) reaction with L . monocytogenes . The mechanism of the cooperative lytic process between L . monocytogenes and R . equi may represent a different and novel mechanism reaction, in which the COX may not act as a conventional second-step factor, and a reaction different to the direct interaction with the cholesterol of the erythrocyte membrane may be involved. J Biochem (Tokyo), 1996 Mar, 119(3), 407 - 13 Photoreactive nitrile hydratase: the photoreaction site is located on the alpha subunit; Tsujimura M et al.; Nitrile hydratase (NHase) from Rhodococcus sp . N-771 exists in active and inactive forms . The inactive NHase is immediately activated by light irradiation and changes to the active form . To characterize the photoreactive center, the inactive NHase was denatured by 6 M urea, and two kinds of subunits (alpha and beta) were separated and purified by anion-exchange chromatography . In a manner similar to the native NHase, the isolated alpha subunit showed two absorption peaks at 280 and 370 nm, which were diminished by light irradiation . However, irradiation failed to elicit the appearance of absorption peaks at around 400 nm and at 710 nm, which were characteristic of the activated enzyme . The beta subunit seemed not to possess any photoreactive chromophore because its absorption spectrum was not altered by light irradiation . Neither of the subunits showed NHase activity before and after light irradiation, but the inactive NHase was reconstituted by incubating the two subunits together in the dark at 4 degrees C for 1 h . Light irradiation of the beta subunit did not affect subsequent complex formation or NHase activity . However, the irradiated alpha subunit could not assemble with the beta subunit, and no activity was recovered . These results demonstrate that the chromophore(s) responsible for the photoactivation of NHase are entirely located on the alpha subunit, and imply that light irradiation induces conformational change of the alpha subunit. Enferm Infecc Microbiol Clin, 1996 Mar, 14(3), 177 - 80 {Rhodococcus equi pneumonia in patients with HIV infection: report of 2 cases and review of the literature}; Berna JD et al.; BACKGROUND: Pneumonia by Rhodococcus equi is infrequent and is associated with patients with important immunosuppression . To date 66 cases of pneumonia by Rhodococcus equi in patients with HIV infection have been published . The diagnosis, problems in determining diagnosis and treatment are discussed . MATERIALS AND METHODS: Two new cases of pneumonia by Rhodococus equi in C3 stage patients with HIV infection are reported . Diagnosis was achieved by study of bronchoalveolar lavage samples with the Apy-Coryne method and gas chromatography . RESULTS: The two patients presented pneumonia, one of which was necrotizing pneumonia with localization in the upper left lung and in the lower right lung, respectively . The clinical manifestations were characterized by respiratory involvement of a subacute course with pleural involvement in both cases and hemoptisis in one . Prolonged, combined antibiotic treatment was administered with good response in both cases . One patient died at one year of diagnosis from consumptive syndrome while the other remains asymptomatic . CONCLUSIONS: Infection by Rhodococcus equi should be suspected in HIV patients with slow evolution pneumonia, especially in the pneumonia is necrotizing . Combined i.v . antibiotic treatment is recommended and followed from 3 to 5 months with an association including clarithromycin. Can J Microbiol, 1996 Feb, 42(2), 99 - 106 Assessment of the biodegradation potential of psychrotrophic microorganisms; Whyte LG et al.; Bioremediation of polluted temperate and cold temperature environments may require the activity of psychrotrophic bacteria, because their low temperature growth range parallels the ambient temperatures encountered in these environments . In the present study, 135 psychrotrophic microorganisms isolated from a variety of ecosystems in Canada were examined for their ability to mineralize 14C-labelled toluene, naphthalene, dodecane, hexadecane, 2-chlorobiphenyl, and pentachlorophenol . A number of the psychrotrophic strains mineralized toluene, naphthalene, dodecane, and hexadecane . None of the psychrotrophs were capable of mineralizing 2-chlorobiphenyl or pentachlorophenol . Those strains demonstrating mineralization activity were subsequently screened by the polymerase chain reaction (PCR) and Southern hybridization of PCR products for the presence of catabolic genes (alkB, ndoB, todCl, and xylE) involved in known bacterial biodegradative pathways for these compounds . Some of the psychrotrophs able to mineralize toluene and naphthalene possessed catabolic genes that hybridized to xylE or todCl, and ndoB, respectively . The alkB PCR fragments obtained from the strains that mineralized dodecane and hexadecane did not hybridize to an alkB gene probe derived from Pseudomonas oleovorans . Psychrotrophic strain Q15, identified as a Rhodococcus sp., also mineralized the C28 n-paraffin octacosane . A gene probe constructed from the "alkB" PCR fragment from strain Q15 did hybridize with the alkB PCR fragments from most of the psychrotrophic alkane biodegraders, indicating that the alkB primers may be amplifying another gene(s), perhaps with low homology to P . oleovorans alkB, which may be involved in the biodegradation of both short chain (dodecane) and longer chain alkanes (hexadecane, octacosane) . All of the psychrotrophic biodegradative isolates examined were capable of mineralization activity at both 23 and 5 degrees C, indicating their potential for low temperature bioremediation of petroleum hydrocarbon contaminated sites. Appl Environ Microbiol, 1996 Feb, 62(2), 403 - 7 Characterization of the expression of the thcB gene, coding for a pesticide-degrading cytochrome P-450 in Rhodococcus strains; Shao ZQ et al.; A cytochrome P-450 system in Rhodococcus strains, encoded by thcB, thcC, and thcD, participates in the degradation of thiocarbamates and several other pesticides . The regulation of the system was investigated by fusing a truncated lacZ in frame to thcB, the structural gene for the cytochrome P-450 monooxygenase . Analysis of the thcB-lacZ fusion showed that the expression of thcB was 10-fold higher in the presence of the herbicide EPTC (s-ethyl dipropylthiocarbamate) . Similar enhancement of the thcB-lacZ expression was found with other thiocarbamate pesticides . Atrazine, simazine, or carbofuran, although metabolized by the system, had no effect on the thcB-lacZ expression . The presence of glucose slightly increased the expression of thcB-lacZ, indicating no catabolic repression of the thcB-lacZ expression . The expression of thcB-lacZ was decreased more than twofold in Luria-Bertani medium . This was due in part to cysteine, which repressed thcB-lacZ expression . It was confirmed that the thcR gene, which is transcribed divergently from thcB, codes for a positive regulatory protein which is essential for the thcB-lacZ expression . Studies of the thcR-lacZ protein fusion showed that the thcR gene is expressed constitutively. Postepy Hig Med Dosw, 1996, 50(5), 533 - 5 {Structure and antigenicity of the major glycolipid from opportunistic bacteria Rhodococcus equi}; Szponar B et al.; Some results from structural and immunological studies of the major glycolipid from Rhodococcus equi were presented . This glycolipid showed to be a glucosylmonomycolate (GMM) with an aliphatic chain C38 . Its value as taxonomic and immunodiagnostic marker was discussed. Eur Radiol, 1996, 6(6), 826 - 30 Radiological findings in nine AIDS patients with Rhodococcus equi pneumonia; Wicky S et al.; Rhodococcus equi (R . equi) infections have been incidentally reported as a cause of pulmonary infection in severely immunocompromised hosts, including AIDS patients . Our purpose is to describe the radiological findings in nine AIDS patients with R . equi pneumonia assessed by bronchoalveolar lavage (BAL), biopsies, cultures of sputum, and hemocultures . All patients were examined by chest radiographs and contrast-medium-enhanced chest CT . Dense pulmonary consolidations with or without cavitations accounted for the most striking radiological patterns . Chest CT also revealed six mediastinal involvements, strongly mimicking a lymphoma . Two of them had multiple bilateral pulmonary nodular opacities . Pleural effusion was not identified . Although intensive therapies were administered, seven among nine patients died within few months . In an AIDS patient living in a rural area or exposed to horses and presenting these radiological patterns, the possibility of R . equi pneumonia should be considered in the differential diagnosis along with other infectious diseases or lymphomas. J Basic Microbiol, 1996, 36(6), 399 - 406 Differentiation of Rhodococcus species by ribotyping; Jorks S; The ribosomal RNA gene restriction patterns (ribotyping) was investigated with respect to the characterization of Rhodococcus species and R . rhodochrous strains . Chromosomal DNA was prepared, digested with BamH I, blotted, and hybridized with acetylaminofluorene-labelled 16 + 23S rRNA from E . coli . The type strains of seven Rhodococcus species studied gave different hybridization patterns in each case . All strains tested were clearly distinguishable by ribotyping . Patterns contained two to eight bands between 1.4 kb and 11.8 kb and demonstrated the high genetic divergence of genus Rhodococcus . Investigation of nine R . rhodochrous strains resulted in patterns with seven or eight bands . One fragment, 4.4 kb in size, was common to all R . rhodochrous strains and appears to be characteristic of R . rhodochrous . Ribotyping was evaluated as a tool for distinguishing between Rhodococcus species. Scand J Infect Dis, 1996, 28(5), 463 - 7 Rhodococcus equi infection in HIV-positive subjects: a retrospective analysis of 24 cases; Arlotti M et al.; Rhodococcus equi causes a rare infection in immunocompromised hosts . We describe 24 cases of infection in patients with AIDS-related complex (ARC)/acquired immunodeficiency syndrome (AIDS) . Pneumonia was always the first manifestation of R . equi infection, but extrapulmonary involvement was also observed . The main sources of bacteria were sputum, bronchial washings and blood . The strains isolated were mainly susceptible to erythromycin, vancomycin, teicoplanin, rifampicin, imipenem and aminoglycosides . Initial treatment should involve an intravenously administered antibiotic combination therapy including imipenem or vancomycin or teicoplanin, followed by orally administered maintenance combination therapy . Drug combinations should be investigated for serum bactericidal activity in vitro . Surgery does not increase survival time and should only be performed in cases that do not respond to antibiotic treatment . Presumptive risks of infection (contact with horses or farm dust, or cohabiting with people affected by R . equi infection) were present in more than 50% of patients . This finding, and the frequency of bacteria in the sputum, are not sufficient proof of transmission between humans, but do suggest the need for respiratory isolation of patients affected by R . equi pneumonia. Microbiol Immunol, 1996, 40(8), 591 - 4 Expression of virulence-associated antigens of Rhodococcus equi is regulated by temperature and pH; Takai S et al.; We recently reported that there are two different virulence-associated antigens correlated with virulence levels in Rhodococcus equi isolates from AIDS patients: virulent R . equi that kills mice with 10(6) cells expresses 15- to 17-kDa antigens and intermediately virulent R . equi that kills mice with 10(7) cells expresses a 20-kDa antigen . Environmental parameters were evaluated for their effects on the expression of these virulence-associated antigens in virulent R . equi strains by immunoblotting using monoclonal antibodies in this study . Expression of these two virulence-associated antigens of R . equi was regulated by pH and temperature; the antigens were produced maximally when the isolates were grown at 38 C and pH 6.5, but were not produced when grown at 38 C and pH 8, nor at temperatures below 30 C . The 20-kDa antigen was found to be located on the cell surface, as were the 15- to 17-kDa antigens, and showed susceptibility to proteolysis by trypsin . These results indicate that expression of the virulence-associated antigens of R . equi is dependent on the environmental conditions. Can J Vet Res, 1996 Jan, 60(1), 29 - 33 Attempts to find phenotypic markers of the virulence plasmid of Rhodococcus equi; De La Pena-Moctezuma A et al.; Four isolates of Rhodococcus equi, from pneumonic foals, and containing the 85 kb virulence plasmid, a porcine isolate containing an 80 kb plasmid, and their plasmid cured derivatives, were examined for 239 phenotypic properties in an attempt to find characters other than the virulence-associated protein (VapA) which might be encoded by the virulence plasmid in organisms grown at 37 degrees C . Tests chosen included those which have previously given variable results for R . equi isolates, since such variability might be attributed to plasmid curing, and characteristics which have been described as properties of plasmids of Rhodococcus species other than R . equi . Tests included cadmium resistance, Congo red binding, resistance to 26 antibiotics, conventional clinical microbiological tests, utilization of 95 different carbon sources, enzymatic activities in API ZYM, fluorogenic assays for exo- and endopeptidase, glycosidase activities, and testosterone degradation . Apart from production of VapA by foal isolates, no phenotypic property was identified in the plasmid-positive isolates . Phenotypic characteristics of R . equi that have not been described before, and might be useful in identification were: metabolism of N-acetyl-beta D-glucopyranoside, alpha- and beta-hydroxybutyric, alpha-ketobutyric and N-acetyl-glutamic acids, of methylpyruvate, heptanoate, nonanoate and stearate esters; exopeptidase activity against alanine-alanine-tyrosine, alanine-phenylalanine-lysine, glycine-arginine, lysine-alanine, and valine-glycine-alanine; endopeptidase activity against arginine and methionine; and hydrolysis of bis-phosphate ester. Trends Microbiol, 1996 Jan, 4(1), 29 - 33 Rhodococcus equi: an emerging opportunistic pathogen; Mosser DM et al.; Rhodococcus equi is emerging as a cause of pneumonia in immunocompromised people, especially those with AIDS . Like mycobacteria, R . equi is phagocytosed by alveolar macrophages and replicates within them . Recent work is beginning to elucidate the cell and molecular biology of this opportunistic pathogen and the host immune response to it. Rev Med Interne, 1996, 17(5), 410 - 4 {Rhodococcus equi pulmonary abscess in HIV infection}; About I et al.; RE is a well-known Gram positive bacillus which is usually pathogenic in animals . Disease in humans is rare, but incidence has clearly increased with the advent of AIDS . In humans, RE predominantly infect people with impaired cellular immunity so that it is considered an opportunistic agent . Its must common manifestation in immuno-compromised patients is a slowly progressive pneumonia which may cavitate . Even with early diagnostic and optimal and prolonged antibiotic therapy, the mortality of RE, infections remain high (20 to 55%) . Problems in clinical and therapic management are illustrated in our two cases of cavitated pneumonia in two AIDS patients. Acta Clin Belg, 1996, 51(2), 101 - 5 Rhodococcus equi infection in 3 AIDS patients; Colebunders R et al.; Three cases of AIDS complicated by Rhodococcus equi infection are reported . At least one of the patients acquired his Rhodococcus infection in Africa . Despite the fact that the R . equi strains were susceptible to tetracycline, erythromycin, amikacin, co-trimoxazole, rifampicin and vancomycin, these antibiotics were clinically not successful . A clinical improvement was observed in only one patient during teicoplanin and imipenem-cilastatin treatment . Multicentre clinical trials are needed to determine the optimal treatment of R . equi infections in AIDS patients. Lett Appl Microbiol, 1996 Jan, 22(1), 66 - 9 Effect of penicillin G on the electroporation of Rhodococcus rhodochrous CF222; Sunairi M et al.; Suitable conditions for the introduction of bacteriophage DNA into cells of Rhodococcus rhodochrous CF222 by electroporation were established, and penicillin G was found to enhance the transfection frequency . When conditions optimal for the parental strain were applied to its colony-morphological mutants, different transfection frequencies were observed . Penicillin G enhanced the transfection frequency of smooth and mucoidal mutants but not of rough mutants. Int J Syst Bacteriol, 1996 Jan, 46(1), 23 - 30 Rhodococcus percolatus sp . nov., a bacterium degrading 2,4,6-trichlorophenol; Briglia M et al.; A bacterial strain that was able to mineralize 2,4,6-trichlorophenol was isolated from a chlorophenol-fed percolator and was identified as a member of the genus Rhodococcus on the basis of chemotaxonomic characteristics and 16S RNA phylogenetic inference data . This organism (strain MBS1T {T = type strain}) exhibited a typical irregular rod-coccus cycle, and the cells had fimbria-like structures on their surfaces . The diagnostic cell wall amino acid was meso-diaminopimelic acid, and the sugars were arabinose and galactose; the mycolic acids contained 46 to 54 carbon atoms . The main menaquinone was MK-8(H2), and MK-9(H2) was a minor component . The cellular phospholipids were phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositolmannoside, phosphatidylglycerol, and diphosphatidylglycerol . Tuberculostearic acid was present . The whole-cell fatty acids were straight-chain acids with 14 to 18 C atoms . The G+C content of the DNA was 67.4 mol% . This organism grew on sucrose, pyruvate, and 2,4,6-trichlorophenol, and it oxidized a large number of carbon compounds, including catechol, 3-hydroxyphenylacetic acid, and phenol . It also exhibited beta-galactosidase, urease, and 2-acetyl-lactate decarboxylase activities . On a phylogenetic tree that was based on 16S ribosomal DNA gene sequences strain MBS1T was found among the rhodococci on an independent branch . On the basis of the chemotaxonomic and phenotypic characteristics of strain MBS1T and its phylogenetic position we suggest that this bacterium should be placed in a new species, Rhodococcus percolatus; the specific epithet was chosen because the organism was isolated by using an enriched percolator . The type strain is strain MBS1. Appl Microbiol Biotechnol, 1995 Dec, 44(1-2), 265 - 70 Soil management enhancing hydrocarbon biodegradation in the polluted Kuwaiti desert; Radwan SS et al.; Oil-polluted Kuwaiti desert samples, exposed to the open air, were subjected to specific types of management, once every 2 weeks, throughout a year; control samples were not treated . The total amounts of extractable alkanes from the control samples remained fairly constant during the dry hot months, but decreased during the rainy months reaching, after 1 year, slightly more than one-half of the amount at zero time . This result demonstrates the self-cleaning of the Kuwaiti desert and the essential role of moisture in this process . Out of the eight types of management studied, the repeated fertilization of the polluted sample with 3% KNO3 solution was most efficient, reducing the extractable alkanes after 1 year to about one-third of zero reading . Repeated fertilization with treated sewage effluent was inhibitory to alkane biodegradation, probably because of increasing soil acidity . The latter inhibitory effect was annulled by liming . Repeated irrigation with 3% NaCl solution was inhibitory, but 1% NaCl solution slightly promoted alkane biodegradation . The various samples contained 10(10)-10(11) oil-utilizing bacteria/g soil, predominantly Bacillus, Pseudomonas, Rhodococcus and Streptomyces . Oil-utilizing fungi were much less frequent and were predominantly Aspergillus and Penicillium species . The microbial numbers varied not only according to the type of soil management but also to the season. Aust Vet J, 1995 Nov, 72(11), 418 - 20 Failure of hyperimmune plasma to prevent pneumonia caused by Rhodococcus equi in foals; Hurley JR et al.; A trial was conducted on a Thoroughbred stud to determine whether or not the administration of anti-Rhodococcus equi hyperimmune plasma would reduce the prevalence of R equi pneumonia (rattles) in foals born in the 1992 horse breeding season . Hyperimmune plasma was administered to 34 foals; another 57 foals were untreated . There was no significant difference in the number of transfused foals developing R equi pneumonia compared with the untreated foals . The time required for recovery from pneumonia between the 2 groups was not significantly different. J Infect Dis, 1995 Nov, 172(5), 1306 - 11 Identification of virulence-associated antigens and plasmids in Rhodococcus equi from patients with AIDS; Takai S et al.; Rhodococcus equi is an emerging opportunistic pathogen of human immunodeficiency virus-infected patients . However, little is known about the characteristics of R . equi isolates from humans . This study characterized the plasmid content, expression of a virulence-associated antigen, and mouse virulence of 19 R . equi isolates from patients with and without AIDS . EcoRI digestion patterns and Southern, Western, and virulence analyses of these isolates with cryptic plasmids allowed definition of a new category of R . equi . Isolates from patients with AIDS tended either to be virulent and have 15- to 17-kDa antigens and an 85-kb plasmid (10(6) bacteria needed for lethality) or have intermediate virulence (10(7) bacteria needed for lethality) and one of four distinct large plasmids that share DNA homology and express a 20-kDa antigen . Most of the non-AIDS isolates were avirulent (> 10(8) bacteria needed for lethality) and did not express any of these antigens. Vet Microbiol, 1995 Oct, 46(4), 383 - 92 Association with HeLa cells by Rhodococcus equi with and without the virulence plasmid; de la Pena-Moctezuma A et al.; HeLa cell association was examined in eight Rhodococcus equi isolates containing 80-85 kb plasmids and their plasmid negative derivatives, and in two other plasmid negative R . equi strains . Seven of the eight plasmid positive strains possessed an 85 kb plasmid and produced the virulence-associated protein (VapA) detected by monoclonal antibody staining in immunoblots; one of the eight had an 80 kb plasmid but did not produce VapA . Curing of the plasmids by repetitive subcultures at 42 degrees C in broth was confirmed by colony and DNA dot blot hybridization with a 7.5 kb BamHI-HindIII plasmid fragment probe, by attempted isolation of plasmid DNA, and by demonstration of lack of VapA . Most strains associated well with HeLa cells and no relationship was found with plasmid status and possession of VapA . Association with HeLa cells was significantly greater for strains with a dry colony type than for those with a mucoid colony, a result which correlated with hydrophobicity of the colonies . HeLa cell association does not correlate with the presence of the virulence plasmid in R . equi. Eur J Epidemiol, 1995 Oct, 11(5), 507 - 12 Pathogenic Nocardia isolated from clinical specimens including those of AIDS patients in Thailand; Poonwan N et al.; Forty strains of nocardioform microorganisms were isolated as clinical specimens including several from AIDS patients in Thailand . Among them, 37 strains were found to belong to the genus Nocardia . Our identification studies revealed that most of the strains (25 strains) belong to the N . asteroides group, i.e., N . asteroides sensu stricto and N . farcinica . Three strains were identified as N . otitidiscaviarum and two strains N . brasiliensis . In addition, 7 strains of rare pathogenic N . transvalensis were also isolatedPIP: Nocardia is an aerobic gram-positive and partly acid-fast bacterium that belongs to the pathogenic actinomycetes . Nocardia can cause both systemic and cutaneous diseases . Cutaneous nocardiosis is thought to be induced by various predisposing factors, the most common of which include corticosteroid therapy, immunosuppressive therapy, and hematological malignancy . In recent years cases of infection have been increasing coupled with the increased use of immunosuppressive agents and the number of AIDS patients . Characterization studies of pathogenic Nocardia isolated clinically in Thailand from 1990 to 1994 were reported . 40 strains of nocardioform microorganisms (Nocardia like actinomycetes with meso-DAP, arabinose, galactose, and mycolic acid) were isolated as clinical specimens including several from AIDS patients . All 40 strains were isolated from clinical specimens at seven hospitals in Bangkok using Sabouraud dextrose agar medium or Ogawa medium . The analysis of mycolic acid profiles on thin-layer chromatography (TLC) plate showed that one strain had the same Rf values as that of Mycobacterium sp . and the remaining 39 strains had similar Rf values to those of Nocardia, Rhodococcus, and Gordona spp . Studies on their menaquinone composition showed that among 39 isolates, 37 strains had MK-8H4 (cycl.) as predominant menaquinone . 2 strains had MK-8(H2) as a predominant menaquinone and both were identified as Rhodococcus spp . 25 strains were found to belong to the N . asteroides group and were further divided into respective species, i.e., 12 strains of N . asteroides in a strict sense and 13 strains of N . farcinica on the basis of Na-citrate utilization, susceptibility to antimicrobial and antitumor agent (tobramycin and 5-fluorouracil), and ability to grow at 45 degrees Celsius . Three strains of N . otitidiscaviarum and two strains of N . brasiliensis were also identified and the remaining seven strains were eventually identified as N . transvalensis . Results of the drug susceptibility pattern test of Nocardia isolates correlated well with those obtained by the traditional identification system . Among 37 cases, there were 10 HIV seropositive and 2 seronegative patients, and the remaining cases were unknown . Further epidemiological studies may be needed to determine a possible association between AIDS and nocardiosis . J Bacteriol, 1995 Oct, 177(20), 5748 - 55 Cloning and expression of the s-triazine hydrolase gene (trzA) from Rhodococcus corallinus and development of Rhodococcus recombinant strains capable of dealkylating and dechlorinating the herbicide atrazine; Shao ZQ et al.; We used degenerate oligodeoxyribonucleotides derived from the N-terminal sequence of the s-triazine hydrolase from Rhodococcus corallinus NRRL B-15444R in an amplification reaction to isolate a DNA segment containing a 57-bp fragment from the trzA gene . By using the nucleotide sequence of this fragment, a nondegenerate oligodeoxyribonucleotide was synthesized and used to screen a genomic library of R . corallinus DNA for fragments containing trzA . A 5.3-kb PstI fragment containing trzA was cloned, and the nucleotide sequence of a 2,450-bp region containing trzA was determined . No trzA expression was detected in Escherichia coli or several other gram-negative bacteria . The trzA gene was subcloned into a Rhodococcus-E . coli shuttle vector, pBS305, and transformed into several Rhodococcus strains . Expression of trzA was demonstrated in all Rhodococcus transformants . Rhodococcus sp . strain TE1, which possesses the catabolic gene (atrA) for the N-dealkylation of the herbicides atrazine and simazine, was able to dechlorinate the dealkylated metabolites of atrazine and simazine when carrying the trzA gene on a plasmid . A plasmid carrying both atrA and trzA was constructed and transformed into three atrA- and trzA-deficient Rhodococcus strains . Both genes were expressed in the transformants . The s-triazine hydrolase activity of the recombinant strains carrying the trzA plasmid were compared with that of the R . corallinus strain from which it was derived. Lett Appl Microbiol, 1995 Oct, 21(4), 261 - 6 An improved Escherichia coli-Rhodococcus shuttle vector and plasmid transformation in Rhodococcus spp . using electroporation; Shao Z et al.; The genetic studies of metabolically diverse Rhodococcus spp . have been hampered by the lack of a system of introducing exogenous DNA . The authors improved an existing Escherichia coli-Rhodococcus shuttle vector (pMVS301) by removing much of the DNA not needed for replication and adding a multicloning site . This improved vector (pBS305) is 7.9 kb in length . Its ability to transform Rhodococcus was tested using electroporation parameters optimized for introduction of pMVS301 into Rhodococcus . Transformation efficiencies as high as 10(5) cfu micrograms-1 DNA were obtained although efficiencies varied depending on the Rhodococcus strain tested . The improved vector pBS305 offers great utility for genetic studies of Rhodococcus because its small size enables movement of large inserts of DNA into Rhodococcus, it has multicloning sites, contains a highly selective thiostrepton marker, and can be replicated in both E . coli and Rhodococcus. Biochim Biophys Acta, 1995 Sep 6, 1251(2), 115 - 24 Bacterial steroid monooxygenase catalyzing the Baeyer-Villiger oxidation of C21-ketosteroids from Rhodococcus rhodochrous: the isolation and characterization; Miyamoto M et al.; Steroid monooxygenase from Rhodococcus rhodochrous, isolated in homogeneity with a high yield, catalyzes Baeyer-Villiger oxidation of progesterone to produce testosterone acetate with the stoichiometric consumptions of NADPH and molecular oxygen . It is a flavoenzyme with the molecular size of 60 kDa in the monomeric form and the isoelectric point of 4.9 . The absorption spectrum has the maxima at 278, 376, and 439 nm and the shoulders at 360 and 465 nm, indicating a strong hypsochromic shift (blue-shift) of the absorption peak in the visible wavelength region . The prosthetic group of the enzyme was identified to be FAD, and the Kd value was estimated to be 0.95 microM . The enzyme catalyzed only the oxidative esterification of progesterone, 11 alpha- and 11 beta-hydroxyprogesterone and not the oxidative lactonization of androstenedione . Km for progesterone was 100 microM, for NADPH was 3.3 microM, and the turnover number was 185 min-1 . Kd values for progesterone, 11 alpha-hydroxyprogesterone, deoxycorticosterone, and androstenedione were 110, 130, 2000, and 450 microM, respectively . The optimum pH of the reaction was about 8.5 . The reaction was inhibited competitively by 17 alpha-hydroxyprogesterone and androstenedione . Amino terminal sequences of the enzymes from the bacterium and also from fungus, Cylindrocarpon radiocicola were considerably different, and the potential flavin-binding site could be detected on the amino-terminal region of the fungus enzyme but not on that of the bacterial enzyme . Western blotting analyses of the two steroid monooxygenases resulted that mouse antiserum raised for each enzyme reacted only with the antigenic enzyme protein but did not show the cross-reactions . It is clarified that bacterial steroid monooxygenase is distinctly different from the fungal enzyme in the molecular and enzymic properties. Zentralbl Veterinarmed B, 1995 Sep, 42(7), 397 - 404 Rapid growth and increased biomass yield of Mycobacterium farcinogenes and some related taxa in broth and agar media; Hamid ME et al.; A broth medium containing yeast extract (4 g/l), glucose (15 g/l), magnesium sulphate (0.5 g/l), tri-sodium citrate (1.5 g/l), potassium sulphate (0.5 g/l), ammonium ferric citrate (trace) and buffered with potassium di-hydrogen phosphate (5 g/l) was formulated and found to support a luxuriant growth of Mycobacterium farcinogenes strains that was superior to the conventional media used before . Similar results were obtained with M . senegalense strains and with representatives of the genera Gordona, Mycobacterium, Nocardia, Rhodococcus and Tsukamurella . Out of 13 diverse agar-based media, M . farcinogenes was found to grow particularly well on Mueller Hinton's medium, followed, in order of decreasing growth rate, by modified Bennett's, DST, tryptic soya and glucose yeast extract agars. Biodegradation, 1995 Sep, 6(3), 237 - 46 Dehalogenation of haloalkanes by Rhodococcus erythropolis Y2 . The presence of an oxygenase-type dehalogenase activity complements that of an halidohydrolase activity; Armfield SJ et al.; Rhodococcus erythropolis Y2 produced two types of dehalogenase: a hydrolytic enzyme, that is an halidohydrolase, which was induced by C3 to C6 1-haloalkane substrates, and at least one oxygenase-type dehalogenase induced by C7 to C16 1-haloalkanes and n-alkanes . The oxygenase-type activity dehalogenated C4 to C18 1-chloroalkanes with an optimum activity towards 1-chlorotetradecane . The halidohydrolase catalysed the dehalogenation of a wide range of 1- and alpha,omega-disubstituted haloalkanes and alpha,omega-substituted haloalcohols . In resting cell suspensions of hexadecane-grown R . erythropolis Y2 the oxygenase-type dehalogenase had a specific activity of 12.9 mU (mg protein)-1 towards 1-chlorotetradecane (3.67 mU mg-1 towards 1-chlorobutane) whereas the halidohydrolase in 1-chlorobutane-grown batch cultures had a specific activity of 44 mU (mg protein)-1 towards 1-chlorobutane . The significance of the two dehalogenase systems in a single bacterial strain is discussed in terms of their contribution to the overall catabolic potential of the organism. J Biol Chem, 1995 Aug 11, 270(32), 18818 - 24 Identification of two new genes in the Pseudomonas aeruginosa amidase operon, encoding an ATPase (AmiB) and a putative integral membrane protein (AmiS); Wilson SA et al.; The nucleotide sequence of the amidase operon of Pseudomonas aeruginosa has been completed and two new genes identified amiB and amiS . The complete gene order for the operon is thus amiEBCRS . The amiB gene encodes a 42-kDa protein containing an ATP binding motif that shares extensive homology with the Clp family of proteins and also to an open reading frame adjacent to the amidase gene from Rhodococcus erythropolis . Deletion of the amiB gene has no apparent effect on inducible amidase expression and it is thus unlikely to encode a regulatory protein . A maltose-binding protein-AmiB fusion has been purified and shown to have an intrinsic ATPase activity (Km = 174 +/- 15 mM; Vmax = 2.4 +/- 0.1 mM/min/mg), which is effectively inhibited by ammonium vanadate and ADP . The amiS gene encodes an 18-kDa protein with a high content of hydrophobic residues . Hydropathy analysis suggests the presence of six transmembrane helices in this protein . The AmiS sequences is homologous to an open reading frame identified adjacent to the amidase gene from Mycobacterium smegmatis and to the ureI gene from the urease operon of Helicobacter pylori . AmiS and its homologs appear to be a novel family of integral membrane proteins . Together AmiB and AmiS resemble two components of an ABC transporter system. Infect Immun, 1995 Aug, 63(8), 3037 - 41 Cytokine modulation alters pulmonary clearance of Rhodococcus equi and development of granulomatous pneumonia; Kanaly ST et al.; Rhodococcus equi, a facultative intracellular bacterium, causes chronic, often fatal granulomatous pneumonia in young horses and in humans with AIDS . The inability of host alveolar macrophages to kill intracellular R . equi results in the development of granulomas and progressive loss of pulmonary parenchyma . Clearance of the organism from the lung requires functional CD4+ T cells . The purpose of this study was to identify the cytokine effector mechanisms that mediate clearance of R . equi from the lung . Mice were treated with monoclonal antibodies (MAbs) to either gamma interferon (IFN-gamma) or interleukin-4 (IL-4) to determine the role of endogenous production of these cytokines in pulmonary clearance of R . equi . Mice treated with an anti-IL-4 or isotype control MAb cleared R . equi by 21 days postinfection and expressed increased levels of IFN-gamma mRNA, as detected by transcriptional analysis of bronchial lymph node CD4+ T cells . In contrast, mice treated with the anti-IFN-gamma MAb failed to express detectable IFN-gamma mRNA, expressed increased levels of IL-4 mRNA, failed to clear pulmonary infection, and developed pulmonary granulomas with large numbers of eosinophils . The enhancement of IL-4 mRNA expression and a predominance of eosinophils in pulmonary lesions of anti-IFN-gamma-treated mice suggest that a nonprotective Th2 response in involved in disease pathogenesis . The association of increased bronchial lymph node CD4+ T-cell IFN-gamma mRNA expression with pulmonary clearance of R . equi suggests that a Th1 response is protective. Jpn J Cancer Res, 1995 Aug, 86(8), 749 - 55 Activation of protein kinase C by mycobacterial cord factor, trehalose 6-monomycolate, resulting in tumor necrosis factor-alpha release in mouse lung tissues; Sueoka E et al.; Cord factors are mycoloyl glycolipids in cell walls of bacteria belonging to Actinomycetales, such as Mycobacterium, Nocardia and Rhodococcus . They induce granuloma formation in the lung and interstitial pneumonitis, associated with production of macrophage-derived cytokines . We studied how cord factors induce biological activities in the cells . Cord factors isolated from M . tuberculosis, trehalose 6-monomycolate (mTMM) and trehalose 6,6'-dimycolate (mTDM), enhanced protein kinase C (PKC) activation in the presence of phosphatidylserine (PtdSer), diacylglycerol and Ca2+, and mTMM activated PKC alpha more strongly than PKC beta or gamma under the same assay conditions . Kinetic studies of mTMM in response to PKC activation revealed that mTMM increased the apparent affinity of PKC to Ca2+ in the presence of both PtdSer and diolein . Although this is similar to observations with unsaturated fatty acids, such as arachidonic acid, mTMM was synergistic with PtdSer for PKC activation, but arachidonic acid was not . mTMM was also different as regards PKC activation, as phorbol ester was . A single i.p . administration of mTMM to mouse induced tumor necrosis factor-alpha (TNF-alpha) in serum and in the lung, which is a unique target tissue of cord factors . Based on our recent finding that TNF-alpha is an endogenous tumor promoter, the correlation between lung cancer and pulmonary tuberculosis is discussed. FEBS Lett, 1995 Jul 3, 367(3), 275 - 9 Pseudomonas aeruginosa aliphatic amidase is related to the nitrilase/cyanide hydratase enzyme family and Cys166 is predicted to be the active site nucleophile of the catalytic mechanism; Novo C et al.; A database search indicated homology between some members of the nitrilase/cyanide hydratase family, Pseudomonas aeruginosa and Rhodococcus erythropolis amidases and several other proteins, some of unknown function . BLOCK and PROFILE searches confirmed these relationships and showed that four regions of the P . aeruginosa amidase had significant homology with corresponding regions of nitrilases . A phylogenetic tree placed the P . aeruginosa and R . erythropolis amidases in a group with nitrilases but separated other amidases into three groups . The active site cysteine in nitrilases is conserved in the P . aeruginosa amidase indicating that Cys166 is the active site nucleophile. Can J Vet Res, 1995 Jul, 59(3), 229 - 31 A physical map of the 85 kb virulence plasmid of Rhodococcus equi 103; de la Pena-Moctezuma A et al.; A physical map of the 85 kb virulence plasmid pOTS from Rhodococcus equi 103 was constructed . The restriction map contains 2 AsnI, 5 BglII, 9 EcoRI, 4 HindIII, and 3 XbaI sites . The positions of the EcoRI and HindIII of pOTS are identical to that of the 85 kb virulence plasmid of R . equi ATCC 33701 reported recently by others . EcoRI restriction fragment sizes were similar in the 85 kb plasmids isolated from 4 horse derived R . equi but, except apparently for the 28.3 and possibly 2.0 and 1.5 kb fragments, were different in an 80.1 kb plasmid isolated from a pig source R . equi. Am J Med Sci, 1995 Jul, 310(1), 31 - 3 Case reports: pericarditis and lymphadenitis due to Rhodococcus equi; Lee-Chiong T et al.; Most patients with Rhodococcus equi infection are immunocompromised by either HIV infection, malignancy, or medication . Diagnosis is frequently missed or delayed because the organisms, resembling diphtheroids on smears, may be regarded as contaminants . Their clinical, pathologic, histochemical, and microbiologic resemblance to mycobacteria can result in misdiagnosis . Two cases were seen recently in our institution . R . equi pericarditis developed in a 29-year-old woman with failed renal transplant and R . equi axillary lymphadenitis developed in an asymptomatic 27-year-old man . These patients are important because the former is the first reported case of R . equi pericarditis, and the second case was unusual because of the absence of immunocompromise. J Comp Pathol, 1995 Jul, 113(1), 85 - 8 Rhodococcus equi-associated necrotizing lymphadenitis in a llama; Hong CB et al.; A case of Rhodococcus equi-associated necrotizing lymphadenitis in a 2-year-old male llama is described . Caseous necrosis, resembling macroscopically that seen in ovine caseous lymphadenitis, was observed diffusely in the tracheobronchial and mediastinal lymph nodes, and in an extensive lesion in the lungs . Necrosis was present to a lesser extent in the spleen and hepatic and gastric lymph nodes . Numerous bacteria-laden macrophages were present around the necrotic areas . The findings suggest that, as in cattle and pigs, the primary targets of R . equi infection in the llama are the lymphoid organs. Biodegradation, 1995 Jun, 6(2), 119 - 26 Metabolism of halohydroquinones in Rhodococcus chlorophenolicus PCP-1; Uotila JS et al.; The actinomycete Rhodococcus chlorophenolicus PCP-1 metabolizes pentachlorophenol into ultimate inorganic end products via tetrachloro-p-hydroquinone . This intermediate was further dehalogenated in the cytoplasm requiring reductant in the cell free system . Tetrafluoro-p-hydroquinone and tetrabromo-p-hydroquinone were also dehalogenated . Chlorophenol analogs, thiol blocking agents and molecular oxygen inhibited the activity . The dehalogenating reactions led to 1,2,4-trihydroxybenzene, which was further metabolized into maleic acid. J Clin Microbiol, 1995 Jun, 33(6), 1624 - 7 Identification of virulent Rhodococcus equi by amplification of gene coding for 15- to 17-kilodalton antigens; Takai S et al.; During a survey of the prevalence of virulent Rhodococcus equi at horse-breeding farms by plasmid and protein profiles, cryptic plasmids of various sizes were found in 66 (3.8%) of 1,725 isolates from feces of horses and 129 (5.9%) of 2,200 isolates from soil . Twenty-two isolates, which contained cryptic plasmids of different sizes, were found by plasmid profiles, and their protein profiles and mouse pathogenicities were examined . Of the 22 isolates, 7 were virulent R . equi, contained both virulence and cryptic plasmids, and expressed 15- to 17-kDa antigens . The remaining 15 isolates were avirulent and did not express the antigens: 6 strains contained cryptic plasmids of two different sizes and 9 strains contained cryptic plasmids of various sizes . A PCR assay was developed for the rapid identification of virulence plasmids of R . equi . Oligonucleotide primers, derived from the sequence of a gene coding for the 15- to 17-kDa virulence-associated antigens of R . equi, amplified a 564-bp product from all the tested isolates harboring a virulence plasmid . This PCR product hybridized with virulence plasmid DNA in the Southern hybridization assay . Virulence plasmid-cured derivatives and all of the tested isolates harboring cryptic plasmids only were negative . The PCR is a rapid, sensitive, and specific test for the identification of virulent R . equi from environmental isolates compared with standard techniques, such as plasmid and protein profiles and the mouse pathogenicity test, and is considered to be a useful tool for epidemiological studies. FEMS Immunol Med Microbiol, 1995 Jun, 11(3), 181 - 90 Pathogenesis of Rhodococcus equi infection in mice: roles of virulence plasmids and granulomagenic activity of bacteria; Takai S et al.; Virulence of Rhocococcus equi ATCC 33701 and its plasmid-cured derivative ATCC 33701P- was compared in BALB/c and C3H/HeJ mice in terms of bacterial growth kinetics and histological changes in the liver, spleen and lungs, and humoral immune responses . Injection with a sublethal dose of 10(6) ATCC 33701 in mice resulted in microabscess formation after rapid multiplication in the liver and spleen by day 4, and then the bacteria were gradually eliminated with the formation of granuloma and the production of specific antibodies against 15- to 17-kDa antigens of the virulent bacteria . By contrast, ATCC 33701P- was avirulent as shown by early elimination of viable bacteria and no evidence of net multiplication in the organs . Histopathological changes consisted of only slight, transient infiltration of neutrophils and macrophages in the liver . Although live ATCC 33701P- did not evoke any humoral or histological responses in the mice, a large inoculum (10(8)) of killed ATCC 33701 and ATCC 33701P- resulted in the formation of granuloma in the liver and accelerated extramedullary hemopoiesis in the spleen . These results suggest that the pathogenesis of R . equi infection involves at least two important virulence determinants, both of which play critical roles in the disease: one is the virulence plasmid, which is required for R . equi to resist and grow within host cells; and the other is the granulomagenic activity that is related to the lipids and nature of the cell wall of the species, which induces the characteristic pathological changes. Arch Microbiol, 1995 Jun, 163(6), 439 - 46 Characterization of the Rhodococcus sp . NI86/21 gene encoding alcohol: N,N'-dimethyl-4-nitrosoaniline oxidoreductase inducible by atrazine and thiocarbamate herbicides; Nagy I et al.; A protein with a mol.mass of 51,000 (ThcE) that was induced in Rhodococcus sp . NI86/21 during assimilation of thiocarbamate herbicides, atrazine, ethanol, propanol, glycerol, propionaldehyde or ethanolamine was identified by two-dimensional electrophoresis . The thcE gene was cloned and sequenced . The deduced amino acid sequence revealed ThcE as a member of group III alcohol dehydrogenases . ThcE displayed strong homology with sequenced subunit fragments of the homodecameric N,N'-dimethyl-4-nitrosoaniline-dependent alcohol oxidoreductases (MNO) of Amycolatopsis methanolica and Mycobacterium gastri . N-Terminal sequence analysis of purified MNO from Rhodococcus sp . NI86/21 confirmed the identity with ThcE . When overproduced in Escherichia coli, ThcE was insoluble and no MNO activity was detected. J Bacteriol, 1995 May, 177(10), 2821 - 6 Characterization of muconate and chloromuconate cycloisomerase from Rhodococcus erythropolis 1CP: indications for functionally convergent evolution among bacterial cycloisomerases; Solyanikova IP et al.; Muconate cycloisomerase (EC 5.5.1.1) and chloromuconate cycloisomerase (EC 5.5.1.7) were purified from extracts of Rhodococcus erythropolis 1CP cells grown with benzoate or 4-chlorophenol, respectively . Both enzymes discriminated between the two possible directions of 2-chloro-cis, cis-muconate cycloisomerization and converted this substrate to 5-chloromuconolactone as the only product . In contrast to chloromuconate cycloisomerases of gram-negative bacteria, the corresponding R . erythropolis enzyme is unable to catalyze elimination of chloride from (+)-5-chloromuconolactone . Moreover, in being unable to convert (+)-2-chloromuconolactone, the two cycloisomerases of R . erythropolis 1CP differ significantly from the known muconate and chloromuconate cycloisomerases of gram-negative strains . The catalytic properties indicate that efficient cycloisomerization of 3-chloro- and 2,4-dichloro-cis,cis-muconate might have evolved independently among gram-positive and gram-negative bacteria. Am J Clin Pathol, 1995 May, 103(5), 649 - 55 Rhodococcus equi--an increasingly recognized opportunistic pathogen . Report of 12 cases and review of 65 cases in the literature; Scott MA et al.; Rhodococcus equi, a gram-positive, weakly acid-fast coccobacillus, initially isolated from horses, is becoming increasingly recognized as an important pathogen for immunosuppressed human hosts since the first human case was reported in 1967 . A review of the English medical literature yielded 53 cases . During the last 11 years, the microbiology laboratories of the authors isolated the organism from 12 patients . Of the total 65 cases, 60 occurred in immunosuppressed patients with HIV infection, malignant neoplasms, or chronic immunosuppressive therapy . The lung is the most common primary site of infection . Typically, the lesion is densely infiltrated by histiocytes with multiple microabscesses . Intracellular gram-positive coccobacilli are easily demonstrated . R equi grows well on routine non-selective media at 35 degrees C . Previously, many cases may have been missed because the organism resembles oropharyngeal commensal diphtheroids . Clinical information with gram and Kinyoun strains on fresh isolates is helpful in recognizing the possibility of R equi infection. Appl Environ Microbiol, 1995 May, 61(5), 2061 - 5 Cloning of the genes for degradation of the herbicides EPTC (S-ethyl dipropylthiocarbamate) and atrazine from Rhodococcus sp . strain TE1; Shao ZQ et al.; The degradation of the herbicides EPTC (S-ethyl dipropylthiocarbamate) and atrazine (2-chloro-4-ethyl-amino-6-isopropylamino-1,3,5-triazine) is associated with an indigenous plasmid in Rhodococcus sp . strain TE1 . Plasmid DNA libraries of Rhodococcus sp . strain TE1 were constructed in a Rhodococcus-Escherichia coli shuttle vector, pBS305, and transferred into Rhodococcus sp . strain TE3, a derivative of Rhodococcus sp . strain TE1 lacking herbicide degradation activity, to select transformants capable of growing on EPTC as the sole source of carbon (EPTC+) . Analysis of plasmids from the EPTC+ transformants indicated that the eptA gene, which codes for the enzyme required for EPTC degradation, residues on a 6.2-kb KpnI fragment . The cloned fragment also harbored the gene required for atrazine N dealkylation (atrA) . The plasmid carrying the cloned fragment could be electroporated into a number of other Rhodococcus strains in which both eptA and atrA were fully expressed . No expression of the cloned genes was evident in E . coli strains . Subcloning of the 6.2-kb fragment to distinguish between EPTC- and atrazine-degrading genes was not successful. Appl Environ Microbiol, 1995 May, 61(5), 2056 - 60 A single cytochrome P-450 system is involved in degradation of the herbicides EPTC (S-ethyl dipropylthiocarbamate) and atrazine by Rhodococcus sp . strain NI86/21; Nagy I et al.; During atrazine degradation by Rhodococcus sp . strain N186/21, N-dealkylated metabolites and an hydroxyisopropyl derivative are produced . The cytochrome P-450 system that is involved in degradation of thiocarbamate herbicides by strain N186/21 (I . Nagy, G . Schoofs, F . Compernolle, P . Proost, J . Vanderleyden, and R . De Mot, J . Bacteriol . 177:676-687, 1995) is also required for atrazine degradation . Atrazine-degrading activity was conferred on the atrazine-negative strains, mutant FAJ2027 of Rhodococcus sp . strain N186/21 and Rhodococcus erythropolis SQ1, upon transformation with the genes encoding the cytochrome P-450 system. Res Microbiol, 1995 May, 146(4), 303 - 13 The sulphydryl-activated cytolysin and a sphingomyelinase C are the major membrane-damaging factors involved in cooperative (CAMP-like) haemolysis of Listeria spp; Ripio MT et al.; The negative mutant approach was used in this study to identify listerial cytolytic factors involved in cooperative haemolysis (CAMP-like phenomenon) with Staphylococcus aureus and Rhodococcus equi . A Listeria monocytogenes non-haemolytic mutant specifically impaired in listeriolysin O (LLO) production gave no CAMP reaction with S . aureus, and was virtually CAMP-negative with R . equi, indicating that the listerial sulphydryl-activated toxin played a major role in cooperative haemolysis . This was confirmed by direct evidence using purified LLO and alveolysin (from Bacillus alvei) in diffusion CAMP assays . To our knowledge, this is the first evidence of involvement of a sulphydryl-activated toxin in cooperative lytic processes . Phosphatidylcholine- and phosphatidylinositol-specific phospholipases C from L . monocytogenes did not seem to significantly contribute to cooperative haemolysis, as the corresponding mutants displayed wild-type CAMP reactions . In contrast, the sphingomyelinase C from Listeria iva-novii was the cytolytic factor responsible for the characteristic shovel-shaped CAMP reaction shown by this listerial species with R . equi . Possible mechanisms of lytic cooperation are discussed. Plasmid, 1995 May, 33(3), 208 - 17 Plasmid pRTL1 controlling 1-chloroalkane degradation by Rhodococcus rhodochrous NCIMB13064; Kulakova AN et al.; Rhodococcus rhodochrous NCIMB13064 can dehalogenate and use a wide range of 1-haloalkanes as sole carbon and energy source . The 1-chloroalkane degradation phenotype may be lost by cells spontaneously or after treatment with Mitomycin C . Two laboratory derivatives of the original strain exhibited differing degrees of stability of the chloroalkane degradation marker . Plasmids of approximately 100 kbp (pRTL1) and 80 kbp (pRTL2) have been found in R . rhodochrous NCIMB13064 . pRTL1 was shown to be carrying at least some genes for the dehalogenation of 1-chloroalkanes with short chain lengths (C3 to C9) . However, no connection was found between the utilization of 1-chloroalkanes with longer chain lengths (C12 to C18) and the presence of pRTL1 . Three separate events were observed to lead to the inability of NCIMB13064 to dehalogenate the short-chain 1-chloroalkanes; the complete loss of pRTL1, the integration of pRTL1 into the chromosome, or the deletion of a 20-kbp fragment in pRTL1 . High-frequency transfer of the 1-chloroalkane degradation marker associated with pRTL1 has been demonstrated in bacterial crosses between different derivatives of R . rhodochrous NCIMB13064. Gene, 1995 Mar 21, 155(1), 135 - 6 Sequence of the Rhodococcus equi gene encoding the virulence-associated 15-17-kDa antigens; Sekizaki T et al.; The nucleotide sequence of the Rhodococcus equi gene encoding the virulence-associated 15-17-kDa antigens, located on plasmid pREAT701, has been determined . The gene encodes a 19-kDa protein of 189 amino acids, with an Ala-rich leader signal sequence (SS) . At least five SS peptidase cleavage sites were found in this region . The molecular diversity of 15-17-kDa antigens might be attributed to the multiple SS peptidase cleavage sites. Vet Med (Praha), 1995 Mar, 40(3), 81 - 6 {The fist detection of Giardia spp . in horses in the Czech Republic}; Pavlasek I et al.; The first occurrence of Giardia spp . in horses in the Czech Republic is reported . During preventive examination of 360 five-month up to 14-year horses from various parts of the region of Central Bohemia carried out from January 1993 to June 1994 in the parasitological laboratory of the State Veterinary Institute in Prague, the Giardia cysts were detected in the excrements of 18 (5%) horses, mostly 2-4 years of age, and in two foals 3 and 6 weeks old . During the period between March 1993 and June 1994, systematic and repeated observation was aimed at a group of 38 racing horses two up to four years of age from two studs in the surroundings of Prague . In one of these studs Giardia spp . cysts were found in 7 horses (35%) out of a total of 20 animals . During bacteriological examination of horses infected with Giardia carried out parallely, only in one animal pathogenic bacteria Rhodococcus equi and Streptococcus equi subsp . zooepidemicus were detected in the excrements . After the application of Entizole (following discontinuation of the preparation on days 4 and 50), however, the result of bacteriological examination was negative . The size of cysts (n = 100) was 12.8-16.0 x 9.6-11.2 microns (with the mean of 14.6 x 9.9 microns) there was no finding of free trophozoites of Giardia in the horse excrements examined . On the basis of morphological characteristics of the protozoon cysts and of the structure of median bodies (following excystation of the Giardia cysts in vitro), the intestinal flagellate found in horses can be included into the morphological group of G . intestinalis.(ABSTRACT TRUNCATED AT 250 WORDS) J Bacteriol, 1995 Feb, 177(3), 676 - 87 Degradation of the thiocarbamate herbicide EPTC (S-ethyl dipropylcarbamothioate) and biosafening by Rhodococcus sp . strain NI86/21 involve an inducible cytochrome P-450 system and aldehyde dehydrogenase; Nagy I et al.; Determination of the N-terminal sequences of two EPTC (S-ethyl dipropylcarbamothioate)-induced proteins from thiocarbamate-degrading Rhodococcus sp . strain NI86/21 resolved by two-dimensional electrophoresis enabled the localization of the respective structural genes on two distinct DNA fragments . One of these strongly induced proteins is a NAD(+)-dependent dehydrogenase active on aliphatic aldehydes . The second protein was identified as a cytochrome P-450 enzyme . The cytochrome P-450 gene represents the first member of a new family, CYP116 . Downstream of the cytochrome P-450 gene, two genes for a {2Fe-2S} ferredoxin (rhodocoxin) and a ferredoxin reductase are located . A putative regulatory gene encoding a new member of the AraC-XylS family of positive transcriptional regulators is divergently transcribed from the cytochrome P-450 gene . By hybridization, it was demonstrated that the aldehyde dehydrogenase gene is widespread in the Rhodococcus genus, but the components of the cytochrome P-450 system are unique to Rhodococcus sp . strain NI86/21 . Overexpression in Escherichia coli was achieved for all of these proteins except for the regulatory protein . Evidence for the involvement of this cytochrome P-450 system in EPTC degradation and herbicide biosafening for maize was obtained by complementation experiments using EPTC-negative Rhodococcus erythropolis SQ1 and mutant FAJ2027 as acceptor strains . N dealkylation by cytochrome P-450 and conversion of the released aldehyde into the corresponding carboxylic acid by aldehyde dehydrogenase are proposed as the reactions initiating thiocarbamate catabolism in Rhodococcus sp . strain NI86/21 . In addition to the major metabolite N-depropyl EPTC, another degradation product was identified, EPTC-sulfoxide. J Appl Bacteriol, 1995 Feb, 78(2), 194 - 9 Establishment of oil-degrading bacteria associated with cyanobacteria in oil-polluted soil; Sorkhoh NA et al.; A unique natural microbial cocktail with promising potential for remediating oil-polluted desert in the Gulf region is reported . Oil-degrading micro-organisms immobilized within dense cyanobacterial mats on oily coasts of the Arabian Gulf were successfully established in oil-contaminated sand . Those micro-organisms biodegraded 50% of the oil within 10-20 weeks . Nocardioforms belonging to the genus Rhodococcus predominated in the first few weeks, but after 22 weeks Pseudomonas spp . increased, sharing Rhodococcus in the predominance . Other oil-utilizing bacterial genera included Bacillus and Arthrobacter . Filamentous actinomycetes belonging to the genera Streptomyces and probably Thermoactinomyces, as well as fungi belonging mainly to Aspergillus and Penicillium increased in the contaminated sand during the experiment but declined later . Representative strains grew on spectra of the tested n-alkanes with chain lengths between C10 and C40, as sole sources of carbon and energy. Appl Environ Microbiol, 1995 Feb, 61(2), 549 - 55 Multiple genes encoding 2,3-dihydroxybiphenyl 1,2-dioxygenase in the gram-positive polychlorinated biphenyl-degrading bacterium Rhodococcus erythropolis TA421, isolated from a termite ecosystem; Maeda M et al.; Rhodococcus erythropolis TA421 was isolated from a termite ecosystem and is able to degrade a wide range of polychlorinated biphenyl (PCB) congeners . Genetic and biochemical analyses of the PCB catabolic pathway of this organism revealed that there are four different bphC genes (bphC1, bphC2, bphC3, and bphC4) which encode 2,3-dihydroxybiphenyl dioxygenases . As determined by Southern hybridization, none of the bphC genes exhibits homology to any other bphC gene . bphC1, bphC2, and bphC4 encode enzymes that have narrow substrate specificities and cleave the first aromatic ring in the meta position . In contrast, bphC3 encodes a meta cleavage dioxygenase with broad substrate specificity . Asturias et al . have shown that the closely related organism Rhodococcus globerulus P6 contains three different bphC genes (bphC1, bphC2, and bpHC3) which encode meta cleavage dioxygenases . The data suggest that there is a diverse family of bphC genes which encode PCB meta cleavage dioxygenases in members of the genus Rhodococcus. Appl Environ Microbiol, 1995 Feb, 61(2), 468 - 75 Sequence and molecular characterization of a DNA region encoding the dibenzothiophene desulfurization operon of Rhodococcus sp . strain IGTS8; Piddington CS et al.; Dibenzothiophene (DBT), a model compound for sulfur-containing organic molecules found in fossil fuels, can be desulfurized to 2-hydroxybiphenyl (2-HBP) by Rhodococcus sp . strain IGTS8 . Complementation of a desulfurization (dsz) mutant provided the genes from Rhodococcus sp . strain IGTS8 responsible for desulfurization . A 6.7-kb TaqI fragment cloned in Escherichia coli-Rhodococcus shuttle vector pRR-6 was found to both complement this mutation and confer desulfurization to Rhodococcus fascians, which normally is not able to desulfurize DBT . Expression of this fragment in E . coli also conferred the ability to desulfurize DBT . A molecular analysis of the cloned fragment revealed a single operon containing three open reading frames involved in the conversion of DBT to 2-HBP . The three genes were designated dszA, dszB, and dszC . Neither the nucleotide sequences nor the deduced amino acid sequences of the enzymes exhibited significant similarity to sequences obtained from the GenBank, EMBL, and Swiss-Prot databases, indicating that these enzymes are novel enzymes . Subclone analyses revealed that the gene product of dszC converts DBT directly to DBT-sulfone and that the gene products of dszA and dszB act in concert to convert DBT-sulfone to 2-HBP. FEBS Lett, 1995 Jan 16, 358(1), 9 - 12 Photosensitive nitrile hydratase intrinsically possesses nitric oxide bound to the non-heme iron center: evidence by Fourier transform infrared spectroscopy; Noguchi T et al.; Nitrile hydratase (NHase) from Rhodococcus sp . N-771 is a photosensitive enzyme that catalyzes hydration of nitriles to the corresponding amides . Light-induced Fourier transform infrared difference spectra between the inactive and active forms of NHase were measured with both the natural (14N) and 15N-labeled NHases . The results showed, for the first time, that NHase intrinsically possesses nitric oxide (NO) molecules bound to the non-heme iron center . The possible role of NO in the photoactivation process of NHase is discussed. Cytotechnology, 1995-96, 19(1), 79 - 88 Succinoyl trehalose lipid induced differentiation of human monocytoid leukemic cell line U937 into monocyte-macrophages; Isoda H et al.; A novel type of succinoyl trehalose lipid (STL-1) prepared from n-hexadecane-culture of Rhodococcus erythropolis SD-74 markedly inhibited the growth of a human monocytoid leukemic cell line, U937, and induced its morphological alteration along a monocyte-macrophage lineage . STL-1 markedly increased differention-associated characteristics in macrophage, such as nitroblue tetrazolium reducing ability, appearance of Fc receptor, phagocytic activities in U937 . Furthermore, U937 cells, which were activated with STL-1 exhibited cytotoxic activity against human lung carcinoma cell line A549 . However, STL-1 did not affect growth of a normal human fetal lung cell line TIG-1 . The individual components of STL-1, neither sugar moiety nor fatty acids in the free form, were effective at inducing the differentiation of U937 cell . From these results, we concluded that STL-1 has low cytotoxicity against normal human cells and the ester molecule itself is responsible for the activity of inducing differentiation of human monocytoid leukemic cell line U937 into monocyte-macrophage which results in the stimulation of the production of some cytotoxic substances. Microbiol Immunol, 1995, 39(7), 499 - 507 Sequential involvement of NK cells and CD8+ T cells in granuloma formation of Rhodococcus aurantiacus-infected mice; Asano M et al.; We investigated the effect of in vivo administration of antibodies against T-cell subsets and natural killer (NK) cells on endogenous gamma interferon (IFN-gamma) production and granuloma formation in Rhodococcus aurantiacus-infected mice . High titers of endogenous IFN-gamma were detected in the extracts of the livers and spleens during 24 hr of the infection, reaching the peak at 8 hr, and the IFN-gamma production was reduced by in vivo administration of anti-NK 1.1 monoclonal antibody (MAb) or antibody against asialo GM1+ cells . Endogenous IFN-gamma declined until 2 days of the infection, then reappeared from 1 week and peaked at 3 weeks . Endogenous IFN-gamma at 1 and 3 weeks was reduced by in vivo administration of anti-CD8 MAb, but not by anti-CD4 MAb or anti-NK 1.1 MAb . Granulomatous lesions in the livers and spleens began to appear from 1 week of the infection and developed in 3 weeks . In vivo administration of rat anti-IFN-gamma MAb reduced the development of granulomas . In addition, granuloma formation was reduced by depletion of NK cells prior to the infection or depletion of CD8+ T cells at 1 week of the infection . Based on these findings, it is presumed that the biphasic production of IFN-gamma is attributable to NK cells in the early phase of the infection and CD8+ T cells in the phase of granuloma formation, and that granuloma formation is regulated by NK cells and CD8+ T cells through the secretion of endogenous IFN-gamma. FEMS Microbiol Lett, 1995 Jan 1, 125(1), 31 - 5 o-, m- and p-hydroxybenzoate degradative pathways in Rhodococcus erythropolis; Suemori A et al.; Rhodococcus erythropolis strain S1 uses the gentisate pathway to metabolize salicylate and m-hydroxybenzoate and the protocatechuate pathway to degrade p-hydroxybenzoate . m-Hydroxybenzoate 6-hydroxylase was induced by growth on m-hydroxybenzoate or gentisate, and salicylate 5-hydroxylase only by growth on salicylate . p-Hydroxybenzoate 3-hydroxylase could be induced only by growth on p-hydroxybenzoate . m-Hydroxybenzoate or p-hydroxybenzoate could repress the induction of salicylate 5-hydroxylase . Maleylpyruvate isomerase in the gentisate pathway did not require reduced glutathione. Int J Syst Bacteriol, 1995 Jan, 45(1), 110 - 5 Amino acid sequence analysis of ribosomal protein AT-L30 from members of the family Pseudonocardiaceae; Ochi K; The phylogenetic relationships of the genera belonging to the family Pseudonocardiaceae were examined by a novel approach, amino acid sequencing of ribosomal AT-L30 proteins . The results of partial amino acid sequencing of AT-L30 preparations revealed that the members of the family Pseudonocardiaceae are divided into four clusters; the first cluster contains the genus Actinopolyspora, the second cluster contains the genus Saccharopolyspora, the third cluster contains the genus Amycolatopsis, and the fourth cluster contains the genera Amycolata, Pseudonocardia, Saccharomonospora, and Kibdelosporangium, indicating a close phylogenetic relationship between the genera Amycolata and Pseudonocardia . The genus Actinokineospora is closely related to the genus Saccharothrix, and these two genera formed a cluster separate from the clusters for the genera of the Pseudonocardiaceae . These results agree in almost all respects with previous 16S rRNA sequencing work by Embley et al . (T . M . Embely, J . Smida, and E . Stackebrandt, Syst . Appl . Microbiol . 11:44-52, 1988) and Warwick et al . (S . Warwick, T . Bowen, H . McVeigh, and T . M . Embley, Int . J . Syst . Bacteriol . 44:293-299, 1994), thus supporting the proposal of Warwick et al . that the genera Amycolata and Pseudonocardia should be combined in an emended genus, Pseudonocardia . However, a discrepancy was found between the present study and that of Warwick et al . In the present study, the Nocardia-Rhodococcus group and the Saccharothrix-Actinokineospora group were both recovered within the clade for the family Pseudonocardiaceae. Acta Cytol, 1995 Jan-Feb, 39(1), 111 - 3 Cytologic appearance of Rhodococcus equi in bronchoalveolar lavage specimens . A case report; Lachman MF; Immunocompromised patients are at risk of developing infections caused by Rhodococcus equi, a gram-positive bacillus that can cause pneumonia in patients with acquired immunodeficiency syndrome . To the author's knowledge this is the first report describing the cytologic features of the infection in a patient who had a confirmatory tissue biopsy and positive culture . Infection with R equi may go unrecognized by pathologists unaware of its presentation and appearance in cytologic material. J Thorac Imaging, 1995 Spring, 10(2), 121 - 5 Radiologic findings in two AIDS patients with Rhodococcus equi pneumonia; Mayor B et al.; Rhodococcus equi (R . equi) has been reported as an occasional cause of pulmonary infection in severely immunocompromised hosts, including AIDS patients . Our purpose is to describe the radiologic findings in two AIDS patients with R . equi pneumonia . Chest radiographs showed right-upper-lobe consolidation and cavitation in both patients . Chest CT confirmed upper mediastinal involvement and precarinal lymphadenopathy in both cases . Multiple lung nodules related to the bronchi were also identified in one patient . In an AIDS patient from a rural area or with exposure to horses, the possibility of R . equi infection should be considered when cavitary pneumonia is present, even if there is mediastinal involvement and/or lymphadenopathy, or if multiple lung nodules are also present. Clin Infect Dis, 1995 Jan, 20(1), 167 - 9 Rhodococcus meningitis in an immunocompetent host; DeMarais PL et al.; Rhodococcus species are increasingly being recognized as pathogens, especially in patients infected with the human immunodeficiency virus . Most cases of rhodococcus infection in these patients are due to Rhodococcus equi and involve the lungs . CNS infections due to Rhodococcus species are rare, and meningitis due to non-equi Rhodococcus has never been reported in a healthy host . We report a case of meningitis due to non-equi Rhodococcus in a previously healthy 24-year-old woman . We also review and summarize the reported cases of CNS infections caused by Rhodococcus species. Can J Vet Res, 1995 Jan, 59(1), 51 - 9 Molecular characterization of a lipid-modified virulence-associated protein of Rhodococcus equi and its potential in protective immunity; Tan C et al.; Virulent strains of Rhodococcus equi produce plasmid-mediated 15- and 17-kDa proteins, which are thermoregulated and apparently surface-expressed . We demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) that R . equi produce three antigenically-related virulence-associated proteins, a diffuse 18-22-kDa, a 17.5-kDa and a 15-kDa protein . Phase partitioning of whole cells of R . equi strain 103 with Triton X-114 (TX-114) and labelling with {3H}-labelled palmitic acid showed that the two higher molecular weight proteins are hydrophobic and lipid modified . The 15-kDa protein did not partition into TX-114 and was not lipid modified . Cloning and expression of a fragment of the R . equi virulence plasmid in Escherichia coli showed that the three proteins were expressed from a single gene . Sequence analysis of this gene (designated vapA) revealed a 570-bp open reading frame encoding a polypeptide of 189 amino acids with a calculated molecular mass of 19,175 Da . The mature, nonlipid modified protein had a calculated mass of 16,246 Da . The 17.5- and 18-22-kDa forms of the protein are therefore due to lipid modification . No significant sequence homology of the vapA gene with other reported nucleotide sequences were found . Opsonization of virulent R . equi with