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Al-Hasani K, Henderson IR, Sakellaris H, Rajakumar K, Grant T, Nataro JP, Robins-Browne R, Adler B. The sigA gene which is borne on the she pathogenicity island of Shigella flexneri 2a encodes an exported cytopathic protease involved in intestinal fluid accumulation. Infect Immun 2000; 68:2457-63. [PMID: 10768931 PMCID: PMC97446 DOI: 10.1128/iai.68.5.2457-2463.2000] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/1999] [Accepted: 01/17/2000] [Indexed: 11/20/2022] Open
Abstract
In this study, the sigA gene situated on the she pathogenicity island of Shigella flexneri 2a was cloned and characterized. Sequence analysis showed that sigA encodes a 139.6-kDa protein which belongs to the SPATE (serine protease autotransporters of Enterobacteriaceae) subfamily of autotransporter proteins. The demonstration that SigA is autonomously secreted from the cell to yield a 103-kDa processed form and possesses a conserved C-terminal domain for export from the cell were consistent with the autotransporter pathway of secretion. Functional analysis showed that SigA is a secreted temperature-regulated serine protease capable of degrading casein. SigA was cytopathic for HEp-2 cells, suggesting that it may be a cell-altering toxin with a role in the pathogenesis of Shigella infections. SigA was at least partly responsible for the ability of S. flexneri to stimulate fluid accumulation in ligated rabbit ileal loops.
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Abstract
The purpose of this study was to evaluate a programme of human immunodeficiency virus (HIV) antibody testing at gay sex clubs. Conducting secondary analyses with 2 datasets, we evaluated HIV-testing preferences of patrons at 2 sex clubs and compared their risks to testers at a standard testing clinic. Sex club testers had significantly more partners and were significantly older than their clinic peers. Sixteen per cent of sex club testers reported that they would not test if testing were not available at the sex club. Gay sex clubs offer an opportunity to reach men at high risk for HIV, some who otherwise may not test.
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Abstract
Pasteurella multocida is an important veterinary and opportunistic human pathogen. The species is diverse and complex with respect to antigenic variation, host predeliction and pathogenesis. Certain serological types are the aetiologic agents of severe pasteurellosis, such as fowl cholera in domestic and wild birds, bovine haemorrhagic septicaemia and porcine atrophic rhinitis. The recent application of molecular methods such as the polymerase chain reaction, restriction endonuclease analysis, ribotyping, pulsed-field gel electrophoresis, gene cloning, characterisation and recombinant protein expression, mutagenesis, plasmid and bacteriophage analysis and genomic mapping, have greatly increased our understanding of P. multocida and has provided researchers with a number of molecular tools to study pathogenesis and epidemiology at a molecular level.
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Cox AJ, Hunt ML, Ruffolo CG, Adler B. Cloning and characterisation of the Pasteurella multocida ahpA gene responsible for a haemolytic phenotype in Escherichia coli. Vet Microbiol 2000; 72:135-52. [PMID: 10699510 DOI: 10.1016/s0378-1135(99)00194-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Haemolysins are membrane-damaging agents which have been described as bacterial virulence factors due to their ability to lyse erythrocytes and other host cells, and therefore inducing a greater inflammatory response (Elliott et al., 1998). Pasteurella multocida was found to be haemolytic under anaerobic conditions. In this study, we cloned and characterised a P. multocida gene, designated ahpA, which conferred a haemolytic phenotype on Escherichia coli when incubated under anaerobic conditions. A deletion was introduced into the ahpA open reading frame which abolished the haemolytic phenotype. The clone containing ahpA showed erythrocyte specificity, causing haemolysis of bovine and equine erythrocytes, and demonstrated weak haemolysis on ovine erythrocytes. Upon further investigation, AhpA was found to affect the expression of the E. coli K-12 latent haemolysin, SheA, under anaerobic conditions.
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Abstract
Colonisation of host tissue by Gram- negative bacteria is facilitated by various adhesins, one of which is type 4 fimbriae (pili). These structures have been associated with pathogenesis in several bacterial species, and have been shown to mediate colonisation of epithelial surfaces. Recently, type 4 fimbriae were identified and characterised from P. multocida strains A, B and D. The type 4 fimbrial subunit protein (PtfA) was identified as an 18-kDa protein which was isolated from whole membrane fractions. We report here the isolation and characterisation of the gene (ptfA) encoding the PtfA protein from P. multocida VP161 (serotype A:1). Part of the gene was cloned on a 2-kb genomic DNA fragment. The complete ptfA gene was obtained using inverse PCR. The gene and its flanking regions were characterised, and the deduced PtfA amino acid sequence was compared to type 4 subunit protein sequences from other bacterial species. The ptfA gene was amplified and sequenced from several P. multocida strains. Comparison of these sequences revealed variation within the type 4 subunit gene of P. multocida.
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Boyce JD, Chung JY, Adler B. Genetic organisation of the capsule biosynthetic locus of Pasteurella multocida M1404 (B:2). Vet Microbiol 2000; 72:121-34. [PMID: 10699509 DOI: 10.1016/s0378-1135(99)00193-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Capsules from a range of bacterial species have been shown to be major virulence determinants and capsule has been implicated in virulence in Pasteurella multocida. Moreover, capsular serogroup appears to be related to disease predilection. Haemorrhagic septicaemia strains belong to serogroup B and E, fowl cholera strains to serogroup A and atrophic rhinitis strains to serogroup D. The entire capsule biosynthetic locus of P. multocida A:1 has been cloned and its nucleotide sequence determined (Chung et al., 1998. FEMS Microbiol. Lett. 166, 289-296); however, nothing is known of the P. multocida B:2 capsule locus. In this work we have determined the nucleotide sequence and genetic organisation of the P. multocida M1404 (B:2) capsule locus. By analogy with the cap loci of other bacteria, the nucleotide sequence can be divided into three functional regions. Regions 1 and 3 comprise six genes involved in transport of the polysaccharide capsule to the cell surface. The deduced products of these genes show high similarity to proteins involved in capsule export in other bacteria. Region 2 comprises nine genes which are likely involved in biosynthesis of the polysaccharide capsule. The deduced products of three of these genes (bcbA, bcbB and bcbC) show significant similarity to proteins known to be involved in polysaccharide biosynthesis while the other six show no similarity to known proteins. However, their organisation indicates they are co-transcribed with bcbA, bcbB, bcbC and the Region 1 capsule export genes, suggesting strongly that they are also involved in capsule biosynthesis.
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157
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Mitchison M, Wei L, Kwang J, Wilkie I, Adler B. Overexpression and immunogenicity of the Oma87 outer membrane protein of Pasteurella multocida. Vet Microbiol 2000; 72:91-6. [PMID: 10699506 DOI: 10.1016/s0378-1135(99)00190-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The outer membrane protein of Oma87 from Pasteurella multocida A:1 has significant similarity to the D15 protective antigen of Haemophilus influenzae (Ruffolo and Adler, 1996). Four fragments of Oma87 from a P. multocida serotype D strain were cloned into a pGEX expression vector and transformed into E. coli JM105. Western blot analysis revealed that convalescent chicken sera reacted with only GST-F1 fusion protein which contained amino acids 18 through to 130 of Oma87 fused to the GST protein. Vaccination with the GST-F1 protein failed to protect chickens against challenge with a virulent P. multocida serotype A.
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159
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Kark JD, Selhub J, Adler B, Gofin J, Abramson JH, Friedman G, Rosenberg IH. Nonfasting plasma total homocysteine level and mortality in middle-aged and elderly men and women in Jerusalem. Ann Intern Med 1999; 131:321-30. [PMID: 10475884 DOI: 10.7326/0003-4819-131-5-199909070-00002] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Elevated plasma total homocysteine level has been associated with cardiovascular disease in many studies, mostly in Europe and North America. Data on persons from other areas and on associations with overall mortality are sparse. OBJECTIVE To determine the relation of plasma homocysteine level to all-cause and cause-specific mortality. DESIGN Prospective observational study with 9- to 11-year follow-up. SETTING A free-living, multiethnic Jewish population in western Jerusalem, Israel. PARTICIPANTS 1788 residents of Jerusalem (808 men and 980 women) who were at least 50 years of age and were examined between 1985 and 1987 as part of the Kiryat Yovel Community Health Study. MEASUREMENTS Nonfasting plasma homocysteine level was determined in frozen stored samples. Deaths during follow-up were identified by linkage with the national population registry. RESULTS Plasma homocysteine levels exceeded 14 micromol/L in 28% of men and 20% of women. During the study period, 405 deaths occurred. In multivariate Cox models that controlled for possible confounders, a nonmonotonic increase in mortality hazard ratios was associated with ascending quintile of homocysteine level: 1.0, 1.4, 1.3, 1.5, and 2.0 (P < 0.001 for trend). The relation was similar for cardiovascular and noncardiovascular causes of death (excluding cancer). The association was weaker when deaths that occurred during the first 5 years of follow-up were excluded; corresponding hazard ratios for ascending quintile of homocysteine level were 1.0, 1.0, 1.2, 1.1, and 1.6 (P = 0.063 for trend). Age- and sex-adjusted percentages of deaths "attributable" to elevated plasma homocysteine level (> or = 14 micromol/L) were 12.5% (95% CI, 6.7% to 18.8%) for all deaths, 16.0% (CI, 7.2% to 25.6%) for deaths during the first 5 years of follow-up, and 8.3% (CI, 1.5% to 16.1%) for later deaths. CONCLUSIONS A mildly to moderately elevated nonfasting plasma homocysteine level is a substantial risk marker for death from all causes. The association seems to be stronger during the first 5 years of follow-up.
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Adler B, Bulach D, Chung J, Doughty S, Hunt M, Rajakumar K, Serrano M, van Zanden A, Zhang Y, Ruffolo C. Candidate vaccine antigens and genes in Pasteurella multocida. J Biotechnol 1999; 73:83-90. [PMID: 10486918 DOI: 10.1016/s0168-1656(99)00111-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pasteurella multocida is the causative agent of fowl cholera and other diseases of production animals. Isolates are classified into five groups based on capsular antigens and into 16 serotypes based on LPS antigens. Strains causing fowl cholera are most frequently designated A:1, A:3 or A:4. Whole cell bacterins can provide some degree of protection, but only against the homologous LPS serotype. There is good evidence that cross-protective antigens are expressed only under in vivo conditions. Empirically derived, live, attenuated vaccines can protect against heterologous serotypes, but because the basis for attenuation is undefined, reversion to virulence is not uncommon. Work in our laboratory is aimed at using a variety of approaches to identify potential protective antigens or virulence genes to be used as candidates for attenuating mutations or as the basis for vaccine antigen delivery systems. The gene encoding an outer membrane protein, Oma87, which is a homologue of the D15 protective antigen of Haemophilus influenzae, was cloned and sequenced. Rabbit antiserum prepared against recombinant Oma87 could passively protect mice against infection. Type 4 fimbriae form the basis of vaccines against ovine footrot and bovine keratoconjunctivitis. We have identified type 4 fimbriae on the surface of P. multocida, purified the fimbrial subunit protein, PtfA, and determined its N-terminal amino acid sequence. Subsequent cloning of the ptfA gene and its inactivation will now be used to assess the importance of type 4 fimbriae in virulence. There has long been anecdotal evidence for the importance of capsule in virulence, but unequivocal genetic evidence for such a role is lacking. We have cloned and characterised the capsule biosynthetic locus in P. multocida A:1 and identified four bex genes involved in capsule transport and genes encoding enzymes involved in the biosynthesis and transfer of the N-acetyl glucosamine and glucuronic acid components of the capsule. It has been suggested that the low concentration of available iron in vivo acts as an environmental cue for expression of cross-protective antigens. Accordingly, we have cloned and characterised the gene encoding transferrin binding protein, Tbpl, so that its role in immunity and virulence can be investigated. Although P. multocida is not normally considered haemolytic, we have observed haemolysis under anaerobic conditions. Standard library construction and screening resulted in the identification of the mesA gene which encodes an esterase enzyme resulting in a haemolytic phenotype under anaerobic conditions. Virulence studies with mesA- mutants were performed to assess its role in pathogenesis. Using a promoterless phoA gene vector system, the cloning of proteins homologous to known surface proteins of other species as well as proteins unique to P. multocida, allowing their potential as vaccine components to be assessed.
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de la Peña-Moctezuma A, Bulach DM, Kalambaheti T, Adler B. Comparative analysis of the LPS biosynthetic loci of the genetic subtypes of serovar Hardjo: Leptospira interrogans subtype Hardjoprajitno and Leptospira borgpetersenii subtype Hardjobovis. FEMS Microbiol Lett 1999; 177:319-26. [PMID: 10474199 DOI: 10.1111/j.1574-6968.1999.tb13749.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Although Leptospira borgpetersenii subtype Hardjobovis and L. interrogans subtype Hardjoprajitno belong to different species, they are serologically indistinguishable and are therefore classified as serovar Hardjo. Since LPS is the major antigen involved in serological classification, this implies that the LPS of these subtypes is identical. Comparison of the LPS biosynthetic loci (rfb) of the subtypes revealed remarkable similarity, with 32 and 31 origins of replication (orfs) in the Hardjoprajitno and Hardjobovis rfb loci, respectively. The order and orientation of these orfs were identical with the exception of an additional orf in Hardjoprajitno between orfs 4 and 5 and intergenic sequences differing between the subtypes. The Hardjoprajitno rfb locus has been divided into four intercalated regions based on sequence similarity to other leptospiral rfb loci. orfJ1-orfJ14 as well as orfJ21-orfJ22 are more similar to regions of the rfb locus of L. borgpetersenii subtype Hardjobovis. orfJ15-orfJ20 as well as orfJ23-orfJ31 are almost identical to the corresponding orfs in L. interrogans serovar Copenhageni. We propose that the progenitor Hardjoprajitno strain, containing an rfb locus which closely resembled the Copenhageni locus, acquired orfs 1-14 and orfs 21-22 from subtype Hardjobovis resulting in two serologically indistinguishable subtypes of serovar Hardjo which in turn constituted the main bovine-adapted leptospiral serovar.
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Kalambaheti T, Bulach DM, Rajakumar K, Adler B. Genetic organization of the lipopolysaccharide O-antigen biosynthetic locus of Leptospira borgpetersenii serovar Hardjobovis. Microb Pathog 1999; 27:105-17. [PMID: 10458921 DOI: 10.1006/mpat.1999.0285] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leptospiral LPS plays a critical role in immunity to leptospirosis and forms the basis for serological classification of Leptospira. However, neither the structure of leptospiral LPS nor the genetics of its biosynthesis have been elucidated. A probe derived from the rhamnose biosynthetic genes of L. interrogans serovar Copenhageni was used to identify the rfb locus of L. borgpetersenii serovar Hardjobovis. Chromosome walking and sequence analysis revealed an rfb locus spanning 36.7 kb, which consists of 31 ORFs transcribed in the same direction. Clusters of genes were identified which encode proteins related to enzymes involved in the biosynthesis of activated sugars including rhamnose. Additional ORFs in the locus encode glycosyltransferases for the assembly of the O-antigen subunit and integral membrane proteins for the transport of O-antigen subunits through the membrane and assembly into LPS.
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163
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Gofin R, Adler B, Hass T. Incidence and impact of childhood and adolescent injuries: a population-based study. THE JOURNAL OF TRAUMA 1999; 47:15-21. [PMID: 10421180 DOI: 10.1097/00005373-199907000-00004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The study of disabilities, use of health services, and absenteeism of parents among 0- to 17-year-old residents of Jerusalem (n = 432) hospitalized for unintentional injuries. METHODS Telephone interviews with parents, 6 months after hospitalization. Disabilities among 4 to 17 year olds were measured by a 25-item scale derived from the International Classification of Impairments, Disabilities, and Handicaps and by limitations of activities. RESULTS Six months after the injury, limitations ranged from 8.3% (daily activities) to 19.4% (sport activities). About one in three presented at least one disability in the 25-item scale. All disabilities were present in higher proportions among adolescents. The more severe injuries whether to the head or other parts of the body presented higher percentages of disabilities. Burns and traffic crashes were associated with higher proportions of disabilities than other causes and with more frequent work absenteeism by their parents. CONCLUSION A relatively large proportion of children remain with long-term disabilities irrespective of cause and body part injured. Because the sequelae of injuries is multifaceted, rehabilitation should include coordination between health and other services.
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164
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Woods WJ, Dilley JW, Lihatsh T, Sabatino J, Adler B, Rinaldi J. Name-based reporting of HIV-positive test results as a deterrent to testing. Am J Public Health 1999; 89:1097-100. [PMID: 10394324 PMCID: PMC1508832 DOI: 10.2105/ajph.89.7.1097] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES This study evaluated attitudes toward name-based reporting of HIV. METHODS One hundred thirty high-risk, male repeat testers received information on the public health benefits of name-based reporting and reported their intentions to test. RESULTS Of the 67 men who were randomly selected and asked their intentions before hearing the benefits, 63% said they would not test if reporting were required. After hearing the benefits, 19% changed their minds (P < .014). Of the 63 men who were asked only after hearing the benefits, 44% would not test. CONCLUSIONS Implementing name-based reporting without working before-hand to change attitudes could undermine the benefits of both testing and HIV surveillance.
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166
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Holmgren H, Adler B. [Time orientation is upset in psychiatric disorders]. LAKARTIDNINGEN 1999; 96:68-70. [PMID: 9951254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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167
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Abstract
Engagement of the TCR may result in proliferation and cytokine release or programmed cell death. These two outcomes may be the consequence of distinct T cell receptor-coupled signal transduction pathways or may reflect quantitative differences in signaling strength via a single pathway. Here we show that genetic inhibition of MAP kinase kinase (MEK) by a dominant negative mutant or through chemical inhibition by PD98059 inhibits IL-2 secretion but not programmed cell death after TCR ligation by superantigen. This supports the hypothesis that T cell cytokine release and apoptosis result from signaling through distinct pathways and implies that the molecular signaling mechanisms regulating apoptosis of mature T cells and negative selection of thymocytes may be similar.
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168
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Hunt ML, Ruffolo CG, Rajakumar K, Adler B. Physical and genetic map of the Pasteurella multocida A:1 chromosome. J Bacteriol 1998; 180:6054-8. [PMID: 9811669 PMCID: PMC107685 DOI: 10.1128/jb.180.22.6054-6058.1998] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A physical and genetic map of the Pasteurella multocida A:1 genome was generated by using the restriction enzymes ApaI, CeuI, and NotI. The positions of 23 restriction sites and 32 genes, including 5 rrn operons, were localized on the 2.35-Mbp single circular chromosome. This report presents the first genetic and physical map for this genus.
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169
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Chappel RJ, Khalik DA, Adler B, Bulach DM, Faine S, Perolat P, Vallance V. Serological titres to Leptospira fainei serovar hurstbridge in human sera in Australia. Epidemiol Infect 1998; 121:473-5. [PMID: 9825801 PMCID: PMC2809547 DOI: 10.1017/s095026889800137x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
A set of 723 diagnostic sera from human patients, submitted for the microscopic agglutination test (MAT) for antibodies to a group of 6 leptospiral serovars, was also tested by MAT for antibodies to the recently-discovered Leptospira fainei serovar hurstbridge. MAT titres of > or = 128 to serovar hurstbridge were detected in 13.4% of these sera, and titres of > or = 512 in 7.2%. In contrast, none of 62 sera obtained from a control population of laboratory staff gave titres of > or = 128. The difference between the number of titres of > or = 128 given by the two groups of sera was highly significant (P < 0.01). The titres observed may have been due to cross-reactions with other leptospiral serovars, but this could not be demonstrated. An alternative explanation is that serovar hurstbridge is present in the human population.
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Abstract
Pasteurella multocida is the aetiological agent of fowl cholera, bovine haemorrhagic septicaemia and atrophic rhinitis in pigs. Many strains of P. multocida express a capsule on their surface. However, nothing is known about the capsule biosynthetic locus in P. multocida although the capsule has been implicated as a virulence factor. The entire capsule locus of P. multocida A:1 was cloned and sequenced. The locus is divided into three regions. Region 1 comprises four ORFs which are involved in the transport of the capsule polysaccharide to the surface. Region 2 comprises five ORFs whose postulated protein products are involved in the biosynthesis of the polysaccharide capsule. Region 3 comprises two ORFs whose postulated products show similarity to proteins that are involved in the phospholipid substitution of the polysaccharide capsule.
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171
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Stich RW, Shoda LK, Dreewes M, Adler B, Jungi TW, Brown WC. Stimulation of nitric oxide production in macrophages by Babesia bovis. Infect Immun 1998; 66:4130-6. [PMID: 9712758 PMCID: PMC108496 DOI: 10.1128/iai.66.9.4130-4136.1998] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/1998] [Accepted: 06/04/1998] [Indexed: 11/20/2022] Open
Abstract
Gamma interferon (IFN-gamma)-activated macrophages are believed to play a key role in resistance to Babesia bovis through parasite suppression by macrophage secretory products. However, relatively little is known about interactions between this intraerythrocytic parasite and the macrophages of its bovine host. In this study, we examined the in vitro effect of intact and fractionated B. bovis merozoites on bovine macrophage nitric oxide (NO) production. In the presence of IFN-gamma, B. bovis merozoites stimulated NO production, as indicated by the presence of increased L-arginine-dependent nitrite (NO2-) levels in culture supernatants of macrophages isolated from several cattle. The merozoite crude membrane (CM) fraction stimulated greater production of NO, in a dose-dependent manner, than did the merozoite homogenate or the soluble, cytosolic high-speed supernatant fraction. Stimulation of NO production by CM was enhanced by as little as 1 U of IFN-gamma per ml of culture medium. Upregulation of inducible NO synthase mRNA in bovine macrophages by either B. bovis-parasitized erythrocytes and IFN-gamma or CM was also observed. B. bovis-specific T-helper lymphocyte culture supernatants, all of which contained IFN-gamma, were also found to induce L-arginine-dependent NO2- production. Supernatants that induced the highest levels of NO also contained biologically active TNF. These results show that B. bovis merozoites and antigen-stimulated B. bovis-immune T cells can induce the production of NO, a molecule implicated in both protection and pathologic changes associated with hemoprotozoan parasite infections.
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172
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Ballard SA, Go M, Segers RP, Adler B. Molecular analysis of the dnaK locus of Leptospira interrogans serovar Copenhageni. Gene X 1998; 216:21-9. [PMID: 9714717 DOI: 10.1016/s0378-1119(98)00329-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Analysis of the dnaK locus of Leptospira interrogans serovar Copenhageni identified four genes in the order hrcA, grpE, dnaK and dnaJ. This is the first time a homologue of hrcA has been identified in a spirochete. The hrcA gene and a regulatory sequence, designated CIRCE, play a significant role in the regulation of the dnaK locus of several Gram+ organisms. Their presence upstream of dnaK in Leptospira suggested a similiar regulatory mechanism. Transcriptional analysis using reverse transcriptase-PCR demonstrated transcription of all four genes and indicated that hrcA and grpE were co-transcribed, as were grpE and dnaK. Whilst hrcA, grpE and dnaK were closely linked on the chromosome, transcription terminators between dnaK and dnaJ and downstream of dnaJ suggested that this latter gene exists in its own operon. Primer extension analysis located functional promoters upstream of hrcA and grpE; however, no evidence of a functional promoter could be found for dnaJ. Moreover, transcripts encompassing the first three genes or the entire locus could not be demonstrated, suggesting that the four genes are regulated independently at the transcriptional level. These results indicate that the regulation of the dnaK locus of Leptospira differs somewhat from that observed in other organisms.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Blotting, Northern
- Cloning, Molecular
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- Escherichia coli Proteins
- Genes, Bacterial/genetics
- HSP70 Heat-Shock Proteins/analysis
- HSP70 Heat-Shock Proteins/genetics
- Leptospira interrogans/chemistry
- Leptospira interrogans/genetics
- Molecular Sequence Data
- RNA, Bacterial/analysis
- RNA, Bacterial/genetics
- Regulatory Sequences, Nucleic Acid
- Sequence Analysis, DNA
- Transcription, Genetic/genetics
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Chappel RJ, Prime RW, Millar BD, Jones RT, Cutler RS, Adler B. Prevalence and geographic origin of pigs with serological evidence of infection with Leptospira interrogans serovar pomona slaughtered in abattoirs in Victoria, Australia. Vet Microbiol 1998; 62:235-42. [PMID: 9791870 DOI: 10.1016/s0378-1135(98)00203-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A set of 10,440 sera was collected from pigs slaughtered at Victorian abattoirs. These sera were subjected to the microscopic agglutination test for antibodies to Leptospira interrogans serovar pomona. Identification of the herd of origin was possible for 6511 pigs, and these were derived from 167 herds in Victoria (84% of sera), from 32 herds in New South Wales (8% of sera) and 29 herds in South Australia (8% of sera). The overall prevalence of titres of 512 and above was 3.7%. This was higher (5.3%) among pigs for which the property of origin was unknown than among pigs with identified properties of origin. Among the latter the prevalence was 2.7% (Victoria 0.6%, New South Wales 1.3%, South Australia 25.2%.) Most of the pigs with unknown properties of origin were derived from market groups and were probably typically from smaller herds. Within Victoria a comparison of results with the known pig populations of the 12 statistical divisions indicated that infection was spread throughout the State. Of the 228 identified herds of origin sampled, 32 (14%) had at least one pig with a high titre. However, this may underestimate the proportion of infected herds, as in many cases only a few serum samples were obtained. Of 73 herds from which 25 or more serum samples were obtained, serological evidence of infection was obtained in 18 herds (25%).
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Perolat P, Chappel RJ, Adler B, Baranton G, Bulach DM, Billinghurst ML, Letocart M, Merien F, Serrano MS. Leptospira fainei sp. nov., isolated from pigs in Australia. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1998; 48 Pt 3:851-8. [PMID: 9734039 DOI: 10.1099/00207713-48-3-851] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pathogenic leptospires can be causative agents of reproductive problems in pigs. Cultures of uteri and kidneys from two pigs herds in New South Wales and Victoria (Australia) yielded five strains identified as Leptospira on morphological and cultural grounds. Phenotypic characteristics (growth at 13 and 30 degrees C, growth in the presence of 8-azaguanine) were intermediate between those of pathogenic and saprophytic leptospires. No cross-agglutination was observed with reference antisera representing the 24 pathogenic serogroups and the main saprophytic ones. Antiserum against one of the strains did not agglutinate reference stains representative of any serogroup. This provided evidence of a new serovar, designated hurstbridge. Genomic characterization of the five strains was achieved using five molecular approaches. Mapped restriction site polymorphisms in the rrs (16S rRNA) gene were not related to those of any reference strains. Arbitrarily primed PCR fingerprints suggested clonality of the five strains. The strains all showed an identical and unique PFGE profile. PCR, using primers specific for the rrs gene of pathologic leptospires, amplified corresponding sequences from the strains. DNA-DNA hybridization (and reciprocal experiments) using the S1 nucleas/TCA method was performed between one of the strains and the reference strains of Leptospira species. The homology ranged from 0 to 36% (the latter being was Leptospira inadai) thus satisfying the criterion of a new species, Leptospira fainei (type strain BUT 6T). Phylogenetic analysis of 16S rRNA sequence showed that L. fainei and L. inadai formed a clade separate from the previously recognized 'saprophyte' and 'pathogen' clades.
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175
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Villamor E, Gofin R, Adler B. Maternal anthropometry and pregnancy outcome among Jerusalem women. Ann Hum Biol 1998; 25:331-43. [PMID: 9667359 DOI: 10.1080/03014469800005682] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Maternal anthropometry, expressed in terms of height, prepregnancy weight and weight gain during pregnancy was studied in 432 Israeli mothers who attended routinely the Hadassah Community Health Centre in Jerusalem, and delivered live births from 1990 to 1994. Among the variables studied, social class was positively associated to mother's height. From five curves fitted with gestational age and weight gain of each woman, a quadratic one was chosen to describe the weight gain pattern of the population. From the model, prepregnancy weight and the weekly rate of weight gain were calculated. Height was positively associated to the rate of weight gain. Gestational age at delivery and gender were the strongest predictors of birth weight, followed by height and rate of weight gain. Three patterns of weight gain were observed: concave, linear and convex. No one of the variables studied was related to the pattern of weight gain as determinant or consequence. Since not all the patterns follow the same shape, the interpretation of adequacy of weight gain at a certain gestational age by using available standards must be done carefully until further studies clarify the relationships between patterns of weight gain and pregnancy outcomes for this population. Prospective studies should be carried out in Israel to control for several factors influencing maternal anthropometry and pregnancy outcomes.
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