John Bates

Microbiology Australia, bringing Microbiologists together

In 2009 there were 233 laboratory-confirmed cases of invasive meningococcal disease (IMD) analysed by the National Neisseria Network, Australia, a nationwide network of reference laboratories. One hundred and thirty-five isolates of Neisseria meningitidis from invasive cases of meningococcal disease were available for which the phenotypes (serogroup, serotype and serosubtype) and/or genotype and antibiotic susceptibility were determined. An additional 98 cases were confirmed by non-culture-based methods (92 by nucleic acid amplification testing (NAAT) and six by serology), and where possible serotyping was determined. Nationally, 194 (83%) laboratory-confirmed cases where a serogroup was determined were infected with serogroup B and 13 (5.6%) serogroup C meningococci. The national total of confirmed cases has remained relatively stable since 2006, but the number of cases may vary between jurisdictions each year. New South Wales had the highest number of recorded cases in 2009. Typical primary and secondary disease peaks were observed in those aged 4 years or less and in adolescents and young adults respectively. Serogroup B cases predominated in all age groups and jurisdictions. The common phenotypes circulating in Australia continue to be B:15:P1.7 and B:4:P1.4. Although serogroup C cases were low, phenotype C:2a:P1.5 again predominated in this group. No evidence of meningococcal capsular 'switching' was detected. Approximately two-thirds of all isolates showed decreased susceptibility to the penicillin group of antibiotics (MIC 0.06 to 0.5 mg/L). All isolates remained susceptible to ceftriaxone. Four isolates had reduced susceptibility to ciprofloxacin, and none to rifampicin.

Background: Brucellosis is primarily a zoonotic disease caused by Brucella species. There are currently ten Brucella spp. including the recently identified novel B. inopinata sp. isolated from a wound associated with a breast implant infection. In this study we report on the identification of an unusual Brucella-like strain (BO2) isolated from a lung biopsy in a 52-year-old patient in Australia with a clinical history of chronic destructive pneumonia. Results: Standard biochemical profiles confirmed that the unusual strain was a member of the Brucella genus and the full-length 16S rRNA gene sequence was 100% identical to the recently identified B. inopinata sp. nov. (type strain BO1^T). Additional sequence analysis of the recA, omp2a and 2b genes; and multiple locus sequence analysis (MLSA) demonstrated that strain BO2 exhibited significant similarity to the B. inopinata sp. compared to any of the other Brucella or Ochrobactrum species. Genotyping based on multiple-locus variable-number tandem repeat analysis (MLVA) established that the BO2 and BO1^Tstrains form a distinct phylogenetic cluster separate from the other Brucella spp. Conclusion: Based on these molecular and microbiological characterizations, we propose that the BO2 strain is a novel lineage of the newly described B. inopinata species.

In 2008, there were 260 laboratory-confirmed cases of invasive meningococcal disease (IMD) analysed by the National Neisseria Network, a nationwide network of reference laboratories. One hundred and forty-nine isolates of Neisseria meningitidis from invasive cases of meningococcal disease were available for which the phenotypes (serogroup, serotype and serosubtype) and antibiotic susceptibility were determined. An additional 111 cases were confirmed by nonculture based methods. Nationally, 223 (85%) laboratory-confirmed cases where a serogroup was determined were infected with serogroup B and 17 (6.5%) infected with serogroup C meningococci. Nationally, the total number of confirmed cases has remained relatively stable since 2006, but the number of cases in each jurisdiction may vary from year to year. Queensland had the highest number of recorded cases in 2008. Typical primary and secondary disease peaks were observed in those aged 4 years or less and in adolescents and young adults respectively. Serogroup B cases predominated in all age groups and jurisdictions. The common phenotypes circulating in Australia were again B: 15: P1.7 and B: 4: P1.4. Although serogroup C cases were numerically low, phenotype C: 2a: P1.5 predominated in this group. No evidence of meningococcal capsular ` switching' was detected. About three-quarters of all isolates showed decreased susceptibility to the penicillin group of antibiotics (MIC 0.06-0.5 mg/L). All isolates remained susceptible to ceftriaxone. One isolate had reduced susceptibility to rifampicin and two to ciprofloxacin.