Central Public Health Laboratory Research Articles

HUMAN CAMPYLOBACTER-ASSOCIATED ENTERITIS ON THE CARIBBEAN ISLAND OF BARBADOS

A longitudinal study of the incidence of Campylobacter enteritis in Barbados was undertaken from January 2000 to August 2003. Diarrheal stools received by the central public health laboratory were cultured for Campylobacter. The number of reported Campylobacter cases exceeded those of Shigella but were less than those of Salmonella, and increased steadily with each year. Isolates from stools were mainly C. jejuni (63.6%) and C. coli (31.8%). The highest isolation rate was found in children 1-4 years of age (40.8%), followed by infants less than 1 year of age (16.9%) and those 5-9 years of age (11.3%). The number of reported cases was higher in March, from June to August, and in November and December. There was no correlation between incidence and either rainfall, temperature, or humidity. Further epidemiologic investigation of this disease is needed to evaluate risk factors for Campylobacter infection and determine routes of transmission in Barbados.

Prevalence Of Compylobacter Species Amongst Hiv/Aids Patients In Nigeria

Method One hundred and sixty stool and rectal swab samples were collected from confirmed HIV patients seen at HIV clinic of Lagos University Teaching hospital and Central public health laboratory Yaba, Lagos. All the patients were heterosexual with age range between 15 and 55 years. The stool samples were collected from both diarrhoea and non diarrhoea patients. Stool samples were cultured on Butzler's virion medium at 43oc with oxygen tension of about 5– 10% for 48 hours. The isolates were subjected to ampicillin, cotrimoxazole, tetracycline, erythromycin, ciprofloxacin and gentamycin. Plasmid profile analysis was carried out on Campylobacter jejuni.

Antiretroviral resistance mutations in human immunodeficiency virus type 1 infected patients enrolled in genotype testing at the Central Public Health Laboratory, São Paulo, Brazil: preliminary results

Antiretroviral resistance mutations (ARM) are one of the major obstacles for pharmacological human immunodeficiency virus (HIV) suppression. Plasma HIV-1 RNA from 306 patients on antiretroviral therapy with virological failure was analyzed, most of them (60%) exposed to three or more regimens, and 28% of them have started therapy before 1997. The most common regimens in use at the time of genotype testing were AZT/3TC/nelfinavir, 3TC/D4T/nelfinavir and AZT/3TC/efavirenz. The majority of ARM occurred at protease (PR) gene at residue L90 (41%) and V82 (25%); at reverse transcriptase (RT) gene, mutations at residue M184 (V/I) were observed in 64%. One or more thymidine analogue mutations were detected in 73%. The number of ARM at PR gene increased from a mean of four mutations per patient who showed virological failure at the first ARV regimens to six mutations per patient exposed to six or more regimens; similar trend in RT was also observed. No differences in ARM at principal codon to the three drug classes for HIV-1 clades B or F were observed, but some polymorphisms in secondary codons showed significant differences. Strategies to improve the cost effectiveness of drug therapy and to optimize the sequencing and the rescue therapy are the major health priorities.

Tetanus vaccination with IL-2 during highly active antiretroviral therapy induces sustained and pronounced specific CD4 T-cell responses

HIV-1 infection results in profound dysfunction of the CD4 T-cell population. Although highly active antiretroviral therapy allows the reconstitution of CD4 T-cell numbers, functional abnormalities remain, including inadequate responses to vaccination. IL-2 increases CD4 T-cell numbers and function. We report the effects of IL-2 given with tetanus vaccination in two patients in a larger immunotherapy study. In one case IL-2 induced sustained responses, which may have been caused by the timing of IL-2 with vaccination.

Performance of commercially available enzyme immunoassays for detection of antibodies against herpes simplex virus type 2 in African populations.

Data are accumulating on the performance of enzyme immunoassays (EIAs) for the detection of herpes simplex virus type 2 (HSV-2) infection in North America and Europe, but little is known about their performance in other populations. Nine test kits were evaluated with 330 serum samples from sub-Saharan Africa. The tests were first compared to the monoclonal antibody (MAb) EIA (Central Public Health Laboratory, London, United Kingdom). Samples that gave discordant results in the MAb EIA and in the three tests that performed best compared to the MAb EIA were tested by Western blotting (University of Washington, Seattle). A random sample of concordant samples was also tested, and the sensitivities and specificities of the different tests were calculated, taking into account this sampling strategy. The sensitivities of the tests ranged from 86 to 100%; the specificities ranged from 47 to 99%. The tests that performed best were the Gull Premier EIA (sensitivity, 86.3%; specificity, 97.6%) and the Kalon Biological (sensitivity, 92.3%; specificity, 97.7%) and Biokit (sensitivity, 86.7%; specificity, 92.6%) tests. It cannot be assumed that enzyme immunoassays for the detection of HSV-2 infection that perform well in industrialized countries will perform equally well in other populations.

Risk factors for acquired multidrug-resistant tuberculosis

Multidrug-resistant tuberculosis (MDR-TB) is a severe and feared problem, that is difficult to control and has shown a tendency to increase worldwide. OBJECTIVE: To analyze the risk factors for acquired MDR-TB. CASUISTIC AND METHODS: A retrospective population-based case-control study was conducted. A bacillus was considered multidrug-resistant whenever it was resistant at least to rifampin (RFP) + isoniazid (INH), and a case was considered as sensitive tuberculosis (TB) if it had undergone the first treatment during a similar period as the first treatment of an MDR-TB case, but was cured at the time of the interview. Case selection was made based on the list of Sensitivity Tests (ST) performed at the Central Public Health Laboratory of the State of Ceará, from 1990 through 1999. The Proportion Method was used to investigate resistance to the six antituberculosis drugs (isoniazid, rifampin, pyrazinamide, ethambutol, ethionamide, streptomycin) used as the standard treatment in Brazil. Controls were selected from the registry of the TB Control Program. Univariate and multivariate analysis were performed, with p < 0.05 considered significant. RESULTS: Out of the 1,500 STs performed during the studied period, 266 strains were multidrug-resistant; 153 patients were identified, 19 of which were excluded. The Group of Cases comprised 134 patients, and the Group of Controls comprised 185. Multivariate analysis helped to detect the following risk factors: lack of home sewer system, alcoholism + smoking, number of previous treatments, irregular treatment, and lung cavities. CONCLUSION: These five factors are important for the development of acquired MDR-TB, and an attempt to neutralize them might contribute to control TB.

Microbiological commissioning and monitoring of operating theatre suites

P. N. Hoffman*, J. Williamsy, A. Staceyz, A. M. Bennettx, G. L. Ridgway{, C. Dobsony, I. Fraser** and H. Humphreysyy *Central Public Health Laboratory, London, UK; yWelsh Health Estates, Cardiff, UK; zReading Public Health Laboratory, Reading, UK; xCentre for Applied Microbiology and Research, Salisbury, UK; {University College London Hospitals, London, UK; **NHS Estates, Leeds, UK and yyRoyal College of Surgeons in Ireland, Beaumant Hospital, Dublin, Ireland

VTEC enteropathogenicity

Journal Article VTEC enteropathogenicity Get access H. Chart H. Chart Laboratory of Enteric Pathogens, Central Public Health Laboratory, London, UK Search for other works by this author on: Oxford Academic Google Scholar Journal of Applied Microbiology, Volume 88, Issue S1, 1 December 2000, Pages 12S–23S, https://doi.org/10.1111/j.1365-2672.2000.tb05328.x Published: 01 December 2000

The serodiagnosis of infection with Salmonella typhi

Background/Aims—The serodiagnosis of infection with Salmonella typhi,using the Widal agglutination assay, relies on patients' antibodies to the O=9,12 lipopolysaccharide (LPS) antigens, H=d flagellar antigens, and the Vi capsular antigens. A...

Evaluation of serotype prediction by cpsA-cpsB gene polymorphism in Streptococcus pneumoniae.

New pneumococcal conjugate vaccines covering a limited number of serotypes are likely to come into widespread use over the next few years. It is unknown what effect this will have on the relative importance of different serotypes as causes of pneumococcal infection. Hence, it will be important to monitor serotype prevalence before, during, and after the introduction of new vaccines. We have investigated the ability of a PCR method based on polymorphisms in two genes common to the different capsule loci to predict the serotype of 93 clinical isolates of Streptococcus pneumoniae submitted to the Central Public Health Laboratory in 1997. Of 70 isolates with vaccine serotypes, 65 were predicted to belong to the correct serotype; this number was improved to 69 with the inclusion of two additional patterns to the database. Of 23 isolates with other serotypes, 19 were correctly predicted as non-vaccine serotypes, the discrepancy lying with four isolates of 6A (non-vaccine serotype) that were indistinguishable from isolates of 6B (vaccine serotype). In situations in which culture of the organism is not feasible, this method could potentially be applicable directly to clinical specimens and could be a valuable aid to the surveillance of pneumococcal serotypes.

Ten-year review of invasive pneumococcal diseases in children and adults from uruguay: Clinical spectrum, serotypes, and antimicrobial resistance

Objectives: Since 1987, the Reference Laboratory of the Ministry of Health of Uruguay has been monitoring infections due to Streptococcus pneumoniae in patients under 5 years of age, in those between 5 to 14 years of age, and in adults. The purpose of the present study was to retrospectively analyze a 10-year collection of invasive S. pneumoniae isolates from children 5 to 14 years of age and adults. Methods: The Reference Children's Hospital, Pasteur Hospital, and two private hospitals in Montevideo as well as four hospitals located in other representative areas of the country participated in the pneumococcal surveillance program. Based on the information available at the Microbiology Department of the Central Public Health Laboratory (demographic data, date and site of isolate, and clinical diagnosis), all patients with an invasive pneumococcal disease were recorded. Pneumonia was clinically and radiologically diagnosed and etiology was assessed by isolation of S. pneumoniae from blood or pleural fluid. All specimens were collected at the Emergency Service. Capsular serotyping and antimicrobial susceptibilities were determined for each isolate. Results: During the 10-year period, 228 invasive S. pneumoniae were identified and included in the study (blood, n = 129; cerebrospinal fluid [CSF], n = 73; pleural fluid, n = 20; peritoneal fluid, n = 3; synovial fluid, n = 1; pericardic fluid, n = 1; abscess, n = 1). The most frequent clinical presentations were pneumonia (n = 71) and meningitis (n = 69). Thirty-five adults had an underlying condition including, four with malignancies, four with lupus, two with human immunodeficiency virus (HIV)-infected, and two patients in hemodialysis among others. Eighteen of the 228 patients died (7.9% fatality rate), but only four of these had an underlying condition. Eleven fatal cases were attributable to meningitis (2 children, 9 and 11 years old; 9 adults, mean age, 59 y). Four patients with pneumonia and three with sepsis died, including a splenectomized woman. Nine different capsular serotypes (1, 5, 7, 9, 12, 15, 19A, 20, and 23A) were identified among the 18 fatal cases. Resistance to penicillin, generally combined with trimethoprim-sulfamethoxazole, fluctuated annually, not surpassing 10%. Conclusions: The study results indicated that 96% of the serotypes involved in severe pneumococcal diseases were included in the 23-valent vaccine and that S. pneumoniae resistance to penicillin was moderate.

Routine use of the gen-probe MTD2 amplification test for detection of Mycobacterium tuberculosis in clinical specimens in a large public health mycobacteriology laboratory

The new version of the Amplified Mycobacterium Tuberculosis Direct Test, MTD2 (Gen-Probe Inc., San Diego, CA) has been implemented as part of the regular testing algorithm for detecting Mycobacterium tuberculosis (MTB) in selected respiratory and non-respiratory specimens in our laboratory. At the Central Public Health Laboratory, Etobicoke, Ontario, we receive specimens for the detection of mycobacteria from all areas of the Province of Ontario. The laboratory processes approximately 25,000 specimens per year, and receives approximately 2000 reference cultures for identification. There are 600 to 700 new cases of tuberculosis detected yearly. Over the 1-year period (1997–98), 823 specimens were tested by MTD2 and the results were compared with radiometric culture (Bactec, Becton Dickinson, Sparks, MD) and clinical diagnosis, giving an overall sensitivity, specificity, positive predictive value and negative predictive values of 100%, 99.6%, 97.4% and 100%, respectively. Two hundred and two cases of respiratory TB and 56 cases of extrapulmonary TB were detected by MTD2 within 0–4 days of specimen arrival in the laboratory. By appropriate selection of specimens for testing, the MTD2 can provide a fast, accurate, and cost-effective method for the detection of MTB in clinical specimens.

Abstracts from the International Symposium—‘‘The Changing Mucosal Flora and Disease'' held at the PHLS Central Public Health Laboratory, London, 6–7th April, 1998

Abstracts from the International Symposium—‘‘The Changing Mucosal Flora and Disease'' held at the PHLS Central Public Health Laboratory, London, 6–7th April, 1998

Marine biotoxins.

Journal of Applied MicrobiologyVolume 84, Issue S1 p. 41S-50S Free Access Marine biotoxins Scoging, Scoging Food Hygiene Laboratory, PHLS Central Public Health Laboratory, Colindale, London, UKSearch for more papers by this author Scoging, Scoging Food Hygiene Laboratory, PHLS Central Public Health Laboratory, Colindale, London, UKSearch for more papers by this author First published: 05 January 2002 https://doi.org/10.1046/j.1365-2672.1998.0840s141S.xCitations: 9 Scoging Food Hygiene Laboratory, PHLS Central Public Health Laboratory, 61 Colindale Avenue, Colindale, London NW9 5HT, UK. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume84, IssueS1July 1998Pages 41S-50S RelatedInformation

Prevalence of glycopeptide resistant coagulase — negative staphylococci (GRCoNS) in patients on oncology, renal and general surgery units: R. Bayston1, A Roshan 1, F Donald 1, A Johnson 2 and ME Kaufman 2, Department of Microbiology, University of Nottingham 1, and Central Public Health Laboratory 2, Colindale, London, England

The protein-binding ability of teicoplanin (TEIC) to neonatal serum was investigated and the following results were obtained. (1) The protein binding ability of TEIC at concentrations ranging from 10 to 100 μg/ml, to neonatal serum was 80.5%-71.9% and was generally low as compared with that for adult serum. (2) The protein binding ability of TEIC (20 μg/ml) to albumin in neonatal serum was not concentration-dependent, and the correlation between the protein-binding ability and albumin concentration was low. Namely, it was suggested that the protein-binding ability of TEIC to neonatal serum was not dependent merely on the albumin concentration, and there was a possibility that the protein-binding ability also depended on qualitative changes in albumin. (3) The protein-binding ability of TEIC (20 μg/ml) to total bilirubin and free bilirubin was not concentration-dependent, and the correlation was extremely low, indicating that there is a low possibility that the protein-binding ability of TEIC induces an increase in free bilirubin.

Rhizopus microsporus in wooden tongue depressors: a major threat or minor inconvenience?

The investigation and management of an apparent outbreak of Rhizopus spp. in a London paediatric referral centre between September 1995 and April 1996 is described. The organism was identified in microbiological surveillance samples from 23 patients nursed in four hospital areas. Investigations revealed the presence of the organism in spatulae from all ward areas investigated and from closed boxed containers held in the central hospital stores obtained from a new supplier. In contrast, culture of spatulae from the initial supplier failed to yield any fungal isolates. The incident was reported to the Medical Device Agency (MDA), the Central Public Health Laboratory Service (CPHLS) and the Birmingham PHLS. A statement was prepared for the weekly Communicable Disease Report and a hazard warning issued by the MDA. The spatulae were withdrawn from use and the contract with the original supplier was re-established. This incident resulted in contamination of samples only and no patient involvement. It highlights the problems which may follow use of equipment for unintended purposes and the need for good manufacturing practice guidelines to be applied to non-sterile equipment used in direct patient care.

Abstracts from the International Symposium - "The Changing Mucosal Flora and Disease" held at the PHLS Central Public Health Laboratory, London, 6-7th April, 1998

Abstracts from the International Symposium - "The Changing Mucosal Flora and Disease" held at the PHLS Central Public Health Laboratory, London, 6-7th April, 1998

Pneumococcal resistance in the UK.

The first case reports of infection with penicillin-resistant pneumococci (PRP, MIC > 0.1 mg/L) and multidrug-resistant pneumococci were made in Australia in 1967 and South Africa in 1977, respectively. Since this time these organisms have spread to become a worldwide problem. In Europe PRP prevalence rates of up to 40% have been reported from Spain and 58% from Hungary, although there has been considerable national, regional and local variation in these figures. Until recently the UK was considered to have low prevalence of PRP. As recently as 1990, 100% of 7255 strains of pneumococci from 61 centres across the UK were found to be penicillin sensitive. However, there have now been several reports of significant and rising levels of resistance nationwide. Erythromycin resistance has also risen from 2.8% to 8.6% between 1990 and 1995 in England and Wales. At the Northern Ireland Public Health Laboratory (NIPHL) 3171 strains of pneumococci were examined using the oxacillin screening test between 1988 and 1995, during which time the annual rate of penicillin resistance was found to increase from <1% to 10.6%. The proportion of PRP with high-level resistance (MIC > 1 mg/L) increased from 0% to 36% and levels of PRP cross-resistance to cephalosporins and ciprofloxacin were 89% and 78%, respectively, which are amongst the highest in the UK. Similar rates of penicillin resistance have now been reported from several geographically disparate regions in the UK including Liverpool, Manchester and London. The number of laboratories in England and Wales reporting the isolation of PRPs to the Central Public Health Laboratory increased from 23 (3%) in 1987 to 72 (21%) in 1991 and a recent study from this reference laboratory showed that the prevalence of pneumococcal resistance to penicillin had increased 2.5-fold between 1990 and 1995. Clearly both PRP and multidrug-resistant pneumococci are increasing in prevalence in the UK, and this increase is likely to continue. A recent model of the evolution of national PRP prevalence rates describes a slow emergence phase, followed by an exponential growth phase of around 10 years reaching a stationary phase when the proportion of PRP reaches 50%. It is possible that the UK is currently at the beginning of the exponential growth phase of PRP. This has implications for the future treatment of pneumococcal infections in this country and emphasizes the need for new anti-pneumococcal agents. The new quinolone grepafloxacin, which has an MIC90 of 0.25 mg/L for pneumococci, may represent a future alternative oral treatment for multidrug-resistant strains. The activity of this antibiotic against 70 PRPs is compared with that of two other quinolones and macrolides.

Enterococci as emerging pathogens of humans.

Journal of Applied MicrobiologyVolume 83, Issue S1 p. 89S-99S Free Access Enterococci as emerging pathogens of humans D. Morrison, D. Morrison Laboratory of Hospital Infection, Central Public Health Laboratory, London, UKSearch for more papers by this authorN. Woodford, N. Woodford Laboratory of Hospital Infection, Central Public Health Laboratory, London, UKSearch for more papers by this authorB. Cookson, B. Cookson Laboratory of Hospital Infection, Central Public Health Laboratory, London, UKSearch for more papers by this author D. Morrison, D. Morrison Laboratory of Hospital Infection, Central Public Health Laboratory, London, UKSearch for more papers by this authorN. Woodford, N. Woodford Laboratory of Hospital Infection, Central Public Health Laboratory, London, UKSearch for more papers by this authorB. Cookson, B. Cookson Laboratory of Hospital Infection, Central Public Health Laboratory, London, UKSearch for more papers by this author First published: 30 October 2003 https://doi.org/10.1046/j.1365-2672.83.s1.10.xCitations: 99 Dr Donald Morrison Laboratory of Hospital Infection, Central Public Health Laboratory, 61 Colindale Avenue, London NW9 5HT, UK (e-mail: dmorriso@phls.co.uk). AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume83, IssueS1October 1997Pages 89S-99S RelatedInformation

HIV-1 Subtypes in Nairobi, Kenya

To the Editor: The provision of specific HIV diagnostic tests and the development of HIV vaccines and antiviral agents depends on understanding the global extent of the diversity of the genome. Sequences of the env and gag genes have been used to classify HIV-1 into a major (M) group, consisting of 10 subtypes designated A through J, and an outlying (O) group of sequences(1,2). The diversity of HIV-1 is probably greatest in Africa(3), and monitoring changes in subtype distribution there may predict the course of the pandemic. Fifteen blood samples were randomly selected from stored samples from a cohort of 684 HIV-1-infected adults from Nairobi, and the lymphocytes were separated. The samples were from six men and nine women; HIV acquisition was assumed to be by heterosexual intercourse, because there were no other known risk factors. Genomic DNA was isolated using a Nucleon I Nucleic Acid Extraction Kit (Scotlab Bioscience, Coatbridge, Strathclyde, U.K.). Portions of the HIV-1 env andgag genes were amplified by polymerase chain reaction methods, subtyped by heteroduplex mobility analysis (HMA), and sequenced as previously described(4-6). Of the 15 samples, 1(K13) failed to amplify with the env or gag primer. The subtyping results are shown in Table 1. The virus was first typed by HMA on Phast gels (Pharmacia, LKB Biotechnology AB, Uppsala, Sweden) using the algorithm previously described(6). A statistically significant result (p < 0.05, Krustal-Wallis test) was obtained by HMA of the 1200-bp amplicon from the env gene for six samples: K0, K2, K3, K6, K8, and K14. Another sample (K7), for which there was no amplification with the 1200-bp primers, gave a statistically significant subtype with the 700-bp env amplicon. Of the other seven samples, one (K13) was not amplified by any of the primers tried, including gag primers(4), and one (K11) produced multiple bands on the gel so that it was not possible to measure the heteroduplex mobility. Amplification and sequencing in thegag gene was used to subtype this sample(4). The remaining five samples (K1, K4, K5, K9, K10) did not give an easily interpretable band pattern when the HMA products were run out on Phast gels, but unequivocal results were obtained using Metaphor XR agarose gels (FMC BioProducts, Kent, U.K.). Sequencing was used to confirm the subtype of these latter samples (K1, K4, K5, K9, K10) and of K3 and K6, which were considered controls.TABLE 1: Subtyping of Kenyan HIV-1 samplesThis work also indicates that, for some samples, care must be taken if HMA alone is used to assign the subtype. The lack of dependability may reflect high sequence diversity, particularly of clade A viral genomes. Infection with more than one strain of HIV-1 and the presence of recombinant or mosaic genomes also may affect the resolution of HMA. In conclusion, we found 12 subtype A, 1 subtype C, and 1 subtype D, confirming the predominance of subtype A in Kenya(3, 7-9). Acknowledgements: This study was supported in part by a SEIMC-Russel-95 grant and by a grant (1995 BEA1300056) from CIRIT, Generalitat de Catalunya, to F. J. Belda. *F. J. Belda †C. Mwchari †M. Hawken *K. L. Barlow *J. P. Clewley *Virus Reference Division; Central Public Health Laboratory; London, United Kingdom;†Clinical Research Centre; Kenya Medical Research Institute; Nairobi, Kenya