Heat treatment enhances the antimicrobial activity of (+)-Catechin when combined with copper sulphate.

UNLABELLED: The aim of the study was to compare the antimicrobial activities of freshly made, heat-treated (HT) and 14 day stored (+)-Catechin solutions with (+)-catechin flavanol isomers in the presence of copper sulphate. (+)-Catechin activity was investigated when combined with different ratios of Cu(2+) ; 100°C heat treatment; autoclaving; and 14 day storage against Staphylococcus aureus. Cu(2+) -(+)-Catechin complexation, isomer structure-activity relationships, and H2 O2 generation were also investigated. Freshly made, HT, and 14 day stored flavanols showed no activity. While combined Cu(2+) -autoclaved (+)-Catechin and -HT(+)-Catechin activities were similar, HT(+)-Catechin was more active than either freshly made (+)-catechin (generating more H2 O2 ) or (-)-Epicatechin (though it generated less H2 O2 ) or 14 day-(+)-Catechin (which had similar activity to Cu(2+) controls-although it generated more H2 O2 ). When combined with Cu(2+) , in terms of rates of activity, HT(+)-Catechin was lower than (-)-Epigallocatechin gallate and greater than freshly made (+)-Catechin. Freshly made and HT(+)-Catechin formed acidic complexes with Cu(2+) as indicated by pH and UV-vis measurements although pH changes did not account for antimicrobial activity. Freshly made and HT(+)-Catechin both formed Cu(2+) complexes. The HT(+)-Catechin complex generated more H2 O2 which could explain its higher antimicrobial activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Natural products attract considerable attention in the search for novel antimicrobials, prebiotics and antioxidants. Enhanced biological activity of natural products has been demonstrated with chemical and heat treatment. This article extends the few publications on heat treatments of plant products and combinations with adjuncts, to raise antimicrobial activity against pathogens such as Staphylococcus aureus. We demonstrated that heat treatment could increase the activity of (+)-Catechin, a weak antimicrobial flavanol found commonly in plants in the presence of copper sulphate. Heat treatment of readily available resources merits consideration in the development of more potent substances for use in clinical settings and agriculture.

Identification of a novel plasmid-associated spectinomycin adenyltransferase gene spd in methicillin-resistant Staphylococcus aureus ST398 isolated from animal and human sources.

OBJECTIVES: Previously described methicillin-resistant Staphylococcus aureus (MRSA) ST398 strains revealed a high frequency of phenotypic resistance to spectinomycin. However, only a few were found to carry the spc resistance determinant. The aim of this study was to identify the genetic mechanism of spectinomycin resistance among spc-negative MRSA ST398 strains. METHODS: Nine spectinomycin-resistant, but spc-negative, MRSA ST398 strains were analysed. The strains were screened for carriage of the spw gene and tested for the presence of transferrable spectinomycin resistance. Plasmid DNA was isolated from all strains and used in transformation assays. The plasmid identified as mediating resistance to spectinomycin was fully sequenced. The function of the novel spectinomycin resistance gene was confirmed by restriction digest inactivation and its distribution was determined using a PCR assay. RESULTS: A single MRSA ST398 strain was spw positive. The remaining strains carried a plasmid that mediated resistance to spectinomycin. Sequence analysis of a single plasmid, termed pDJ91S, revealed that it was 3928 bp in size and contained three open reading frames: a novel spectinomycin resistance gene, designated spd, as well as a repN gene and a rec gene. The XmnI digest inactivation of the spd gene resulted in a 4-fold decrease in spectinomycin MIC. The spd gene was detected in seven other spectinomycin-resistant MRSA ST398 strains that carried a plasmid comparable in size to pDJ91S. CONCLUSIONS: A novel gene, designated spd, that confers resistance to spectinomycin has been identified on a small plasmid in MRSA ST398.

Complete sequence of pSAM7, an IncX4 plasmid carrying a novel blaCTX-M-14b transposition unit isolated from Escherichia coli and Enterobacter cloacae from cattle.

The same plasmid carrying blaCTX-M-14b was identified from an Escherichia coli isolate and an Enterobacter cloacae isolate collected from cattle in the United Kingdom by complete plasmid sequencing. This 35,341-bp plasmid, pSAM7, had an IncX4 backbone that is 99% identical to that of pJIE143 from a human isolate in Australia. PCR screening identified pSAM7-like plasmids in three other E. coli isolates of different multilocus sequence types isolated from cattle on different farms in the United Kingdom.

Detection and characterization of pCT-like plasmid vectors for blaCTX-M-14 in Escherichia coli isolates from humans, turkeys and cattle in England and Wales.

OBJECTIVES: To detect and characterize Escherichia coli strains and pCT-like plasmids implicated in the dissemination of the CTX-M-14 gene in animals and humans, in England and Wales. METHODS: UK CTX-M-14-producing E. coli (n=70) from cattle (n=33), turkeys (n=9), sheep (n=2) and humans (n=26) were screened using multiplex PCR for the detection of a previously characterized plasmid, pCT. Isolates found to be carrying two or more pCT genetic markers were further analysed using PFGE. Their antimicrobial-resistance genes and virulence genes were also determined. These plasmids were transferred to Salmonella enterica serotype Typhimurium 26R and further examined for incompatibility type, genetic environment of the bla(CTX-M-14) gene, size, restriction fragment length polymorphism (RFLP) and nikB sequence. RESULTS: The 25 E. coli isolates carrying pCT genetic markers generated 19 different PFGE profiles, and 23 isolates had different virulence and antimicrobial-resistance gene patterns. One isolate from cattle was a verotoxigenic E. coli ('VTEC'); the rest were commensal or extra-intestinal pathogenic E. coli. pCT-like plasmids with similar molecular characteristics (size, replicon type, RFLP pattern, pCT markers and genetic environment of the bla(CTX-M-14) gene) were detected in 21/25 of the field isolates, which comprised those from cattle (n=9), turkeys (n=8) and humans (n=4). All pCT-like plasmids were conjugative, and most were IncK (n=21) and had the same local genetic environment flanking the bla(CTX-M-14) gene (n=23). RFLP analysis demonstrated ≥ 75% similarity among most plasmids (n=22). CONCLUSIONS: pCT-like plasmids were common vectors for horizontal dissemination of 30% of the bla(CTX-M-14) genes to different E. coli isolates from humans, cattle and turkeys.

Effects of chelating agent and environmental stresses on microbial biofilms: relevance to clinical microbiology.

AIMS: To determine the effect of pH, temperature, desiccation, ethylenediaminetetraacetic acid (EDTA) and desferrioxamine B (DFO) on Panton-Valentine leukocidin-positive community acquired methicillin-susceptible Staphylococcus aureus (PVL +ve CA-MSSA) biofilm formation. METHODS AND RESULTS: Biofilms from PVL +ve CA-MSSA (clinical isolate) were subjected to pH, temperature, desiccation, EDTA and DFO. PVL +ve CA-MSSA were more resistant to pH and heat than their planktonic equivalents. Desiccation studies demonstrated that PVL +ve CA-MSSA biofilms were more refractory to the treatment than planktonic cells. Significant inhibition of PVL +ve CA-MSSA biofilm formation was observed in the presence of 1 mmol l(-1) EDTA. Low concentrations (2·5 µmol l(-1) ) of DFO enhanced the growth of PVL +ve CA-MSSA biofilms. At higher concentrations (1 mmol l(-1) ), DFO did inhibit the growth but not as much as EDTA. A combination of EDTA and DFO inhibited PVL +ve CA-MSSA biofilm formation at lower concentrations than either alone. CONCLUSIONS: This study demonstrates that PVL +ve CA-MSSA biofilms are resistant to environmental stress but their growth can inhibited effectively by a mixture of EDTA and DFO. SIGNIFICANCE AND IMPACT OF THE STUDY: The inhibition of biofilm formation by PVL +ve CA-MSSA using chelating agents has not been previously reported and provides a practical approach to achieve the disruption of these potentially important biofilms formed by an emerging pathogen.

Hepatitis C virus prevalence and serotypes associated with HIV in The Gambia.

Hepatitis C virus (HCV) serotypes are important in the epidemiology and pathogenesis of HCV-related disease, but little is known of this connection in West Africa. Coinfection with human immunodeficiency virus (HIV) is associated with significant morbidity and mortality. This study aims to determine the prevalence of HCV and its serotypes associated with HIV in The Gambia. A total of 1500 individuals referred to the Royal Victoria Teaching Hospital for HIV serology between July and December, 2002 were screened for antibodies to HIV and subsequently for HCV, and seropositive samples were typed. This study shows HIV and HCV prevalence of 6.7% and 1.6%, respectively, with a co-infection rate of 0.6%. Serotype 2 showed the highest prevalence (58.1%), followed by serotype 1 (19.4%). Prevalence of HCV serotype 3 was 6.5% and five samples were untypeable. Co-infection of HIV-1 with HCV serotype 1 showed a prevalence of 44.4%, and with HCV serotype 2 of 33.3%. The findings support the evidence to suggest the West African subregion as the origin of HCV serotype 2. It also demonstrates the need for routine HCV screening of HIV-infected persons and blood donations, and calls for further studies to elucidate the sources of the HCV virus.

Cattle, weather and water: mapping Escherichia coli O157:H7 infections in humans in England and Scotland.

Entero-haemorrhagic Escherichia coli O157:H7 is a zoonotic pathogen, responsible for a relatively small number of food poisoning and illness outbreaks each year, when compared with other food-borne bacteria capable of causing infections in the population. Nevertheless, E. coli O157:H7 is a bacterial pathogen associated with severe human illnesses including bloody diarrhoea and haemolytic uremic syndrome occurring in both outbreak and sporadic settings. In England and Wales approximately 1% of all laboratory-confirmed cases of food poisoning are the result of E. coli O157:H7; however, in Scotland this figure increases to 3%. When the size of the population is taken into account and the rate of E. coli O157:H7 confirmed cases per 100,000 population is examined, the rate of E. coli 0157:H7 infections in Scotland is much greater than England and Wales. The routes of transmission have changed over time, with new routes of transmission such as farm visits emerging. The prevalence of E. coli O157:H7 has a seasonal dependency, with greater faecal shedding of the organism in the warmer months; this is directly mirrored in the increased reporting of E. coli O157:H7 infection among hospitalized patients. This review attempts to suggest why this phenomenon occurs, paying particular attention to weather, animal movement and private water supplies.

Antimicrobial pomegranate rind extracts: enhancement by Cu(II) and vitamin C combinations against clinical isolates of Pseudomonas aeruginosa.

Recently, natural products have been further evaluated as sources of antimicrobial agents with efficacies against a variety of microorganisms. This study reports the antimicrobial activities of pomegranate rind extract (PRE) in combination with Fe(II) and Cu(II) salts against extended-spectrum multidrug-resistant Pseudomonas aeruginosa. Antimicrobial suspension assays were carried out using aqueous extract of pomegranate alone or in combination with metals salts against P. aeruginosa. The extract:metal salt combination was also enhanced with the addition of vitamin C. Marked activities were observed for the aqueous PRE/Cu(II) preparations, which were greatly enhanced by the addition of the reductant vitamin C. In contrast, the aqueous PRE/Fe(II) preparations were inactive, regardless of addition of vitamin C. The combination of PRE and Cu(II) salts and vitamin C showed the greatest activity against clinical isolates of P. aeruginosa. These results warrant further investigation of PRE as a potential source of new antimicrobial agents.

Prevalence of HIV-1, HIV-2, hepatitis C and co-infection in The Gambia.

BACKGROUND: In most West African countries, the distribution and risk factors for co-infection with Human Immunodeficiency Virus (HIV) and Hepatitis C Virus (HCV) is unknown despite the current HIV epidemic and evidence of increasing prevalence of HCV in the region. OBJECTIVE: This study aimed to evaluate the distribution and the risk factors for the transmission of co-infection between HIV and HCV in The Gambia. METHODS: A total of 1500 persons referred for HIV serology at the Royal Victoria teaching Hospital were interviewed following informed consent to obtain information on their demographic variables, knowledge of sexually transmitted diseases and their prevention, and patterns of risk behavior. Blood was collected and tested for anti-HIV and anti-HCV antibodies by Enzyme Linked Immunosorbent Assay (ELISA). RESULTS: In the general population, the prevalence of HIV was 6.7%, while that of HCV was 2.1%. Both infections occurred more frequently in males than in females. HIV and HCV coinfection rate was 0.6%. Co-infection was significantly more common in males than females. All types of infection--HIV, HCV and HIV/HCV co-infections occurred much more in polygamous settings than in monogamy. CONCLUSION: This study has demonstrated the extent of coinfection with HIV and HCV in The Gambia. The prevalence of female circumcision may be a contributory occurrence factor in the transmission of HIV but not in that of HCV.

Biochemical and genetic variation in Mycoplasma fermentans strains from cell line, human and animal sources.

AIMS: To investigate the inter-strain variation in (i) substrate utilization and (ii) the restriction fragment length polymorphism (RFLP) pattern based on the distribution of an insertion element (IS1550) in Mycoplasma fermentans strains, and to establish any correlation between subgroups within the species and their source or habitat. METHODS AND RESULTS: Using a sensitive dynamic pH method, the pattern and kinetics of substrate utilization by a panel of 17 M. fermentans strains from various sources was determined. This study correlated the biochemical characteristics of these strains with RFLP patterns based on the distribution of an insertion sequence (IS1550) with the sources of the strains. The test isolates were divided into four major groups according to the pattern of substrates metabolized. Interestingly, two strains isolated from cell lines in RFLP cluster I failed to utilize arginine. Ovine strains showed distinct substrate utilization patterns and produced RFLP patterns not previously encountered. CONCLUSIONS: All strains utilized glucose, but the ability to utilize arginine, fructose and N-acetyl glucosamine varied. There was also some correlation evident between the metabolic data and the RFLP clusters. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has provided a better understanding of the biochemical and genetic diversity of M. fermentans strains from various sources.

CD4+ lymphocyte values and trends in individuals infected with human immunodeficiency virus and/or co-infected with hepatitis C virus in the Gambia.

OBJECTIVES: This study was undertaken to monitor the CD4+ lymphocyte count in individuals infected with Human Immunodeficiency Virus (HIV) and/or co-infected with Hepatitis C Virus (HCV) and to compare this with the counts in normal individuals in The Gambia. METHODS: Blood samples were taken from 1500 individuals referred for HIV serology at the Royal Victoria Teaching Hospital (RVTH) following informed consent. Samples were tested for antibodies to HIV by the Murex ELISA, antibodies to HCV by the Ortho ELISA, and CD4 counts determined by the Dynalimmunomagnetic cell isolation method RESULTS: Of the 1500 patients screened for HIV and HCV antibodies, 6.7% (101/1500) were infected with HIV, 0.6 % (9/1500) were co-infected with HCV and 1.5 % (22/1500) were infected with HCV alone. Almost half (44.6%; 25/56) of HIV-1 infected patients had a CD4+ lymphocyte count at diagnosis of 200 cells/microl or less as compared to 41.7 % (10/24) of HIV-2 and 75% (6/8) of HIV-D infected patients. The rate of CD4 decline was higher among HIV/HCV co-infected persons than individuals infected with HIV or HCV. The rate of decline was higher among men than women. These differences did not reach statistical significance due in large part to the small number of participants who completed the programme. The CD4+ lymphocyte count of apparently healthy Gambian male and females was 489 cells/microl and 496 cells/microl respectively. This rate is lower than that reported for Caucasians, but in agreement with the global range. CONCLUSION: A significant progressive decline in CD4+ lymphocyte count was observed among the female control group who were negative for HIV and HCV. This finding is unclear and calls for a longitudinal study involving a cohort of women in this region.

Induction of oxidative DNA damage by Helicobacter pylori in HT29 cells.

Infection with Helicobacter pylori has been associated with the development of gastric adenocarcinoma in humans. Several routes have been implicated, the main one being oxidative DNA damage resulting from chronic inflammation, which accompanies infection. However, DNA has been demonstrated in human cells after in vitro incubation with H. pylori sonicates. Using the fragment length analysis using restriction enzymes (FLARE) assay, this study investigates the DNA damaging potential of three clinical isolates of H. pylori on cultured HT29 cells. Significant amounts of oxidative DNA damage were detected in HT29 cells following a 72-hour incubation with each H. pylori isolate. As tumour induction is a known consequence of oxidative DNA damage, chronic infection with the organism may lead to the development of adenocarcinoma of the stomach.

Human immunodeficiency virus and hepatitis C co-infection in sub-Saharan West Africa.

Co-infection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is becoming a major global problem, leading to increased morbidity and mortality in developed countries. Co-existence in sub-Saharan West Africa of a high prevalence of HIV and HCV, which share similar behavioural risk factors and modes of transmission, must be seen in the broader context of an emerging third epidemic of HIV and HCV co-infection, as many factors that may affect the spread of HIV and HCV co-infection are endemic in the continent, including host factors such as sexual behaviour, presence of other sexually transmitted diseases, female and male circumcision status, percutaneous and perinatal exposure, and poverty. This review examines the epidemiology, risk factors and transmission of HIV and HCV co-infection and draws attention to the possible emergence of an epidemic of HIV and HCV co-infection in the region.

Hepatitis C antibodies in asymptomatic first-time blood donors in The Gambia: prevalence and risk factors.

This study evaluates the seroprevalence and risk factors for hepatitis C (HCV) antibodies in asymptomatic first-time blood donors in The Gambia. The study population includes 460 blood donors (age range: 18-40 years [mean: 27.5]) who attended the Royal Victoria Teaching Hospital from July to December 2002. Antibodies to hepatitis C are determined using and enzyme-linked immunosorbent assay (ELISA) test system. The prevalence of hepatitis C found in this study was 1.1% (95% CI, 0.16-1.12). Previous history of sexually transmitted disease, married men in polygamous relationships, and hospital or clinic-based workers were determined to be at risk of acquiring hepatitis C. The study shows that seroprevalence of hepatitis C in The Gambia is low compared to other countries in the region.

GaIN (Georgia Interactive Network for Medical Information) study on health professionals' search requests and continuing education needs.

Health sciences librarians are being called upon to be more proactive in their institutions' continuing education efforts. In an effort to identify whether search requests indicated CE needs, a study was conducted by a group of members of GaIN (Georgia Interactive Network for Medical Information). MEDLINE requests from health care professionals for subject specific clinical topics were collected during a six-month period via a standard search request form created for the study. Copies of all completed requests were collected and broad ICD-9 codes assigned to the search topics. Institutional reports were generated for each participating library to share with hospital CE coordinators. They were also compiled for the group as a whole, and reflected the "hottest" topics requested during the study period for physicians and for non-physicians (nurses, allied health, administrators). A survey to hospital librarians and CE educators showed some value in the reports, but greater potential for further collaboration between librarians and CE coordinators.

Antibodies to Klebsiella pneumoniae in Dutch patients with ankylosing spondylitis and acute anterior uveitis and to Proteus mirabilis in rheumatoid arthritis.

OBJECTIVE: To determine whether the association between increased humoral reactivity against Klebsiella and HLA-B27 associated diseases could be confirmed in Dutch patients with ankylosing spondylitis (AS) and acute anterior uveitis (AAU). METHODS: Under coded conditions sera from Dutch patients with AS, AAU, and rheumatoid arthritis (RA) and from HLA-B27 positive and negative healthy controls were studied for IgA anti-Klebsiella (K54) and IgG anti-Proteus antibodies with the indirect immunofluorescence assay on whole bacteria fixed in suspension with paraformaldehyde. Each group consisted of at least 17 sera. RESULTS: IgA anti-Klebsiella antibody titers were elevated in AS and HLA-B27 negative AAU compared to the HLA-B27 positive and negative controls or patients with active RA (p < 0.001). Furthermore, patients with active RA had elevated levels of IgG antibodies against P. mirabilis compared to every other test or control group (p < 0.001). There was no significant difference between the AS and RA patients in terms of serum C-reactive protein levels, although these were significantly elevated in both compared to healthy controls (p < 0.001), suggesting that the antibody elevations were not due to a nonspecific inflammatory effect. The same sera were blindly tested with negative results by 2 other centers. The discrepancies are probably the result of differences in the methods used. CONCLUSION: Our data support the hypothesis that Klebsiella are involved in the pathogenesis of AS and AAU and that the same might be true for Proteus in RA.

Vaccination against bacterial gut infections.

Recent developments in the field of vaccination against gut-borne bacterial illness are reviewed, including the major pathogens such as salmonella, shigella, cholera and Escherichia coli. The approaches covered range from immunization with killed and live attenuated organisms to genetically detoxified toxin molecules and DNA vaccination and transgenic foods. Both homologous and heterologous responses to various organisms and vector technologies are discussed in murine, bovine and human models, and conclusions are drawn regarding their potential use in the development of safe, effective and economically viable vaccines.

Antibodies to Klebsiella, Proteus, and HLA-B27 peptides in Japanese patients with ankylosing spondylitis and rheumatoid arthritis.

OBJECTIVE: To determine whether patients with ankylosing spondylitis (AS) and patients with rheumatoid arthritis (RA) from Japan have antibodies to Klebsiella pneumoniae and Proteus mirabilis and to assess whether such antibodies are activated against peptides sharing sequences with HLA-B27. METHODS: Serum samples from 152 Japanese patients, 52 with AS, 50 with RA, and 50 healthy controls, were tested against 3 bacteria (K. pneumoniae, P. mirabilis, and Escherichia coli) and 3 synthetic peptides (HLA-B27, pullulanase-D, and scrambled pullulanase-D control peptide) by ELISA under coded conditions. Samples were tested for elevations in IgG, IgA, and IgM antibody classes in patients with active AS or RA, in patients with RA with probable disease, and in patients with inactive AS. Disease activity was determined by an elevated serum C-reactive protein (> 10 mg/l) level and elevated erythrocyte sedimentation rate (> 20 mm/h). RESULTS: Patients with active AS showed specific elevations in serum IgA antibody levels against K. pneumoniae compared to patients with RA and controls (p < 0.001). No such elevation was seen in the IgG and IgM antibody classes. Patients with inactive AS showed no elevation in any class of antibody against K. pneumoniae compared to controls or patients with RA. Patients with active or probably active RA showed significant elevations in IgG antibody levels against P. mirabilis compared to AS and controls (p < 0.001). Patients with AS (active or inactive), RA (active or probably active), and controls showed no elevations in any antibody class to E. coli. Both active and inactive AS patients had specific autoantibodies against HLA-B27 peptide compared to patients with RA and controls (active AS: IgG, IgA, IgM, p < 0.001; inactive AS: IgG and IgA, p < 0.001). Patients with active AS had IgG and IgA antibodies against pullulanase-D peptide, which contains a sequence that cross reacts with HLA-B27 compared to controls (p < 0.001). CONCLUSION: These results provide the first evidence of AS and RA patients in Japan having specific elevations of antibody to K. pneumoniae and P. mirabilis, respectively. This suggests that K. pneumoniae in AS and P. mirabilis in RA may play a role in triggering and/or exacerbating these diseases.

Molecular mimicry: the geographical distribution of immune responses to Klebsiella in ankylosing spondylitis and its relevance to therapy.

The discovery that HLA-B27 is linked to ankylosing spondylitis (AS) and HLA-DR1/DR4 to rheumatoid arthritis (RA) has provided new approaches to the study of the possible causation of these diseases. Several theories have been proposed to explain these associations but only one, namely "molecular mimicry", has provided a specific aetiological agent for each of these diseases. Molecular mimicry between HLA-B27 and two molecules in Klebsiella microbes: nitrogenase and pullulanase D has been reported whilst in Proteus microbes, the haemolysin molecule shows sterochemical similarity to HLA-DR1/DR4. Elevated immune responses to Klebsiella microbes have been demonstrated in AS patients from 10 different countries and this wide geographical distribution suggests that the same aetiological agent is probably acting in producing this condition. Furthermore RA patients show similar immune responses to Proteus microbes. Whether AS or RA are caused by these bacteria can only be resolved by tissue typing all rheumatological patients early, in the course of their disease and then assessing their response to antibiotic chemotherapy in longitudinal studies involving double-blind crossover trials. It is possible that in the future, the course of AS or even RA could be modified by adequate antibiotic chemotherapy or even diets which affect the substrates on which these bacteria grow.

Elevation in anti-Proteus antibodies in patients with rheumatoid arthritis from Bermuda and England.

OBJECTIVE: To determine whether patients with rheumatoid arthritis (RA) from Bermuda and England have an increased anti-Proteus antibody titer when compared to healthy Bermudian and English controls, and to ascertain whether any increase in antibody titer is specific by testing 4 other microbes, Escherichia coli and 3 normal anaerobic bowel bacteria. METHODS: Antibody titers were measured by ELISA and indirect immunofluorescence (IIFA) under coded conditions. RESULTS: Elevated titers of anti-Proteus antibodies were demonstrated in 34 patients with active RA from Bermuda when compared to 33 healthy Bermudian controls by ELISA (p < 0.001) and IIFA (p < 0.001). An elevation of anti-Proteus antibodies was also observed in 34 patients with RA from England when compared to 30 healthy English controls again by ELISA (p < 0.001). A similar antibody elevation in 31 patients with RA from England was observed when compared to 30 healthy controls when measured by IIFA (p < 0.001). However, there was no significant elevation in antibody titers against E. coli or the 3 normal bowel flora isolates in the patients with RA from both countries compared to their respective controls, when measured by ELISA. CONCLUSION: A specific elevation in the immune response to Proteus mirabilis has been demonstrated in patients with RA from both Bermuda and England. However, this study cannot distinguish between antibody association with disease per se and association with disease activity. The role of Proteus in RA and the effect of anti-Proteus therapy in patients with RA merits further study.