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M S Brett

Publications and source records attributed to M S Brett.

10 recordsLinked to original sources
PubMed1999

A significant increase in antimicrobial resistance among pneumococci causing invasive disease in New Zealand.

AIMS: To review the prevalence of antibiotic resistance and the distribution of capsular types among pneumococci from invasive disease in New Zealand from 1995 through 1997. METHOD: Pneumococci isolated from sterile sites that were referred to the Institute of Environmental Science and Research (ESR) were tested for antimicrobial susceptibility and capsular type. RESULTS: A total of 994 pneumococci were referred by 27 hospital and community laboratories. Almost 74% of the isolates were from patients aged < 15 years or > or = 60 years. The majority (88.2%) of the isolates were from blood cultures. In 1997, cefotaxime-resistant pneumococci were confirmed for the first time from invasive disease in New Zealand. Over the three years, 6.0% of the pneumococci were penicillin-nonsusceptible (MIC > or = 0.12 mg/L) and 3.7% were cefotaxime-nonsusceptible (MIC > or = 1 mg/L). Penicillin nonsusceptibility increased significantly from 1.9% in 1995 to 6.2% in 1996 and 9.9% in 1997. Similarly, cefotaxime nonsusceptibility increased from 0.6% in 1995 to 3.5% in 1996 and 6.9% in 1997. In descending order of frequency, the ten most common capsular types were 14, 19, 6, 9, 1, 4, 18, 7, 23, and 3. Eighty-three percent of the penicillin-nonsusceptible pneumococci belonged to serotypes 9V, 19A, 19F, 23F, 14 and 6B and 90% belonged to serotypes included in the 23-valent vaccine. CONCLUSIONS: The increasing prevalence of antimicrobial resistance among pneumococci highlights the need for continued surveillance and for effective measures to prevent pneumococcal infections.

Adolescent↗
PubMed1998

A small outbreak of listeriosis associated with smoked mussels.

Two perinatal listeriosis cases in Auckland, New Zealand, which were diagnosed during November and December 1992 gave histories of consuming Brand X smoked mussels. Listeria monocytogenes was isolated from an unopened packet of mussels collected from the refrigerator of one of the cases. Cultures of L. monocytogenes from the two patients were indistinguishable from those recovered from the mussels by serogrouping and DNA macrorestriction analysis using pulsed-field gel electrophoresis (PFGE). PFGE analysis of isolates of an additional fifteen clinical cases caused by L. monocytogenes serogroup 1/2 which occurred in New Zealand during 1991 and 1992, revealed two more isolates with indistinguishable PFGE patterns. PFGE analysis of a further 222 L. monocytogenes serogroup 1/2 isolated in New Zealand from food and the environment did not reveal any more cultures with the Brand X PFGE type. A combination of serotyping, phage typing, DNA restriction fragment length polymorphism analysis (RFLP), cadmium and arsenic sensitivity testing, and PFGE analysis was used to subtype 38 isolates of L. monocytogenes. The isolates comprised: (a) the isolates from four patients; (b) 26 isolates from 15 packets of Brand X mussel products from retail sale, the processing factory, and the refrigerator of one of the patients; (c) seven isolates from environmental swabs taken in the processing factory; and (d) an isolate from Brand X mussel product from a wholesaler in the United Kingdom. The isolates from three of the clinical cases, 26 of the products and four from the factory environment were indistinguishable using all the subtyping systems. This is the first description from New Zealand of a link between cases of listeriosis, a contaminated food, and the food production environment which was microbiologically confirmed using a combination of subtyping methods for L. monocytogenes.

Animals↗
PubMed1998

Antimicrobial resistances among Shigella in New Zealand.

AIM: To determine the prevalence of antimicrobial resistances among recent isolates of Shigella in New Zealand. METHOD: A total of 107 Shigella isolates referred to the Institute of Environmental Science and Research from 20 hospital and community laboratories between January and June 1996 were tested by an agar dilution method. RESULTS: Shigella sonnei accounted for 70% of the isolates and S flexneri for 23%. Resistance to ampicillin and cotrimoxazole was detected in 42% and 57% of the isolates respectively, and combined ampicillin and co-trimoxazole resistance occurred in 30.8% of the isolates. The prevalence of cephalothin resistance was 5.6%. Resistance to cefotaxime, ciprofloxacid and gentamicin was not detected and 31.8% were sensitive to all agents tested. Ampicillin resistance was significantly more prevalent in S flexneri than S sonnei. CONCLUSIONS: The high prevalence of ampicillin and cotrimoxazole resistance indicates that ampicillin and cotrimoxazole are no longer useful for empirical treatment of shigellosis in New Zealand. The findings indicate a need to monitor the prevalence of antimicrobial resistances among Shigella and suggest that antimicrobial susceptibility testing might be needed to guide antimicrobial therapy.

Anti-Bacterial Agents↗
PubMed1996

Pneumococci causing invasive disease in New Zealand, 1987-94: serogroup and serotype coverage and antibiotic resistances.

AIMS: Development of polysaccharide-conjugated pneumococcal vaccines, prompted by the ineffectiveness of the current 23-valent vaccine for young children, requires an understanding of the pneumococci causing invasive disease worldwide. We have reviewed the capsular serogroups and serotypes, and the antibiotic resistances of pneumococci identified from invasive disease in New Zealand, for the period 1987-94. METHODS: Pneumococci referred from invasive disease were serogrouped and serotyped using the Neufeld test and allocated a capsular type according to the Danish system of nomenclature. Antibiotic susceptibility testing was performed by an agar dilution method following National Committee for Clinical Laboratory Standards (NCCLS) guidelines. RESULTS: A total of 1506 pneumococci were examined of which, 584 (39.8%) were sourced from children less than 15 years and 573 (39%) were from adults 60 years or greater. The majority (88.3%) were from blood cultures. In descending order of frequency serogroups or serotypes 14, 19, 6, 9, 23, 7, 4 and 1 were common to all age-groups but serogroups 6 and 18 were significantly (p < 0.001) associated with children under 15 years and serotype 3 with adult patients. Penicillin resistance was demonstrated by 22 (1.4%) isolates, five of which showed high level resistance (MIC > or = 2 mg/L) and multidrug resistance. Fourteen percent of all isolates were resistant to at least one antibiotic and serogroups 23, 6, 18, 19 and serotype 14 accounted for 82.6% of these resistant isolates. CONCLUSIONS: The serogroups and serotypes found most frequently associated with pneumococcal disease, and antibiotic resistance, were consistent with those described overseas. Continuing surveillance of antibiotic resistances and serotypes of pneumococci causing invasive disease is recommended.

Adolescent↗
PubMed1993

The sero-diagnosis of heartwater: a comparison of five tests.

Five serological tests, the indirect and competitive ELISA, the indirect fluorescent antibody (IFA) test with 2 different antigens and the Western blot technique were compared and applied to sera that were known to be either negative or positive against Cowdria ruminantium or that were collected from animals in heartwater-free regions. No false positive reactions were recorded with any of the tests against the known negative sera. Except for minor variations in the sensitivity of the 5 tests, there was good correlation between them. Their specificity, however, remains in dispute since in all 5 tests extensive cross-reactions were recorded with antibodies in response to an as yet unidentified agent, probably Ehrlichia.

Animals↗
PubMed1992

Antibiotic susceptibilities, serotypes and auxotypes of Neisseria gonorrhoeae isolated in New Zealand.

OBJECTIVE: The aim of the study was to determine the distribution of auxotypes and serotypes and the prevalence of antibiotic resistance among New Zealand isolates of Neisseria gonorrhoeae. MATERIALS AND METHODS: A total of 486 gonococci isolated in 1988 were auxotyped, serotyped, and tested for susceptibilities to ten antibiotics. RESULTS: The gonococci were susceptible to all the antibiotics tested except penicillin and tetracycline. Eleven (2.2%) produced beta-lactamase, one (0.2%) showed chromosomal penicillin resistance, and 18 (3.7%) were resistant to a low-level of tetracycline. Most of the gonococci belonged to six auxotypes. The three predominant auxotypes were arginine-requiring (Arg-), non-requiring (NR), and arginine, hypoxanthine, uracil-requiring (AHU-). The majority of the isolates belonged to serogroup IB and to six serovars. The most prevalent serovars were IB-3 and IB-1. There was an association between penicillin susceptibility and auxotype or serovar among non-penicillinase producing N. gonorrhoeae (PPNG) isolates. CONCLUSIONS: Antibiotic resistance, including penicillin resistance, remains uncommon among gonococci in New Zealand. Baselines have been established for future epidemiological studies using both auxotyping and serotyping.

Animals↗
PubMed1989

Conjugal transfer of gonococcal beta-lactamase and conjugative plasmids to Neisseria meningitidis.

The filter mating of a gonococcal isolate, carrying the 3.2 Md beta-lactamase and 24.5 Md conjugative plasmids with a plasmid-free strain of Neisseria meningitidis, resulted in the transfer of both plasmids to the meningococcus. Transconjugants were able to maintain both plasmids and transfer the 3.2 Md plasmid to another meningococcal strain in a subsequent filter mating.

Conjugation, Genetic↗