A foodborne outbreak of campylobacteriosis at a wedding - Melbourne, Australia, 2022.

Campylobacter is the most common bacterial cause of foodborne gastroenteritis in Australia; however, outbreaks caused by the pathogen are relatively uncommon. In March 2022, the Victorian Department of Health was notified of a gastrointestinal illness in 20 guests following attendance at a wedding reception. Two of these individuals were notified with laboratory-confirmed campylobacteriosis, and an investigation was undertaken to identify the source of the infection and implement strategies to prevent further illness. A case-control study was conducted to determine the likely source of infection. Cases were defined as attendees of the wedding reception, with onset of diarrhoea and/or abdominal cramping 1-10 days after attending the function. Controls were randomly selected from the remaining list of non-ill guests. Cases and controls were interviewed using a standardised, menu-based questionnaire. Food preparation processes were documented, and food samples collected. A total of 29 wedding guests met the case definition. Cases reported onset of illness 2-5 days following the wedding and major symptoms included abdominal cramping (100%), diarrhoea (90%), headache (79%), and fever (62%). Two cases were hospitalised, one with ongoing secondary neurological sequelae. Illness was significantly associated with consumption of a duck breast brioche canapé containing duck liver parfait (odds ratio = 2.85; 95% confidence interval: 1.03-7.86). No leftover food samples were available for testing. The investigation found that the duck canapé was the likely vehicle of infection. Consistent with the literature on Campylobacter transmission, it is likely that inadequate cooking of the duck liver for the parfait was the contributing factor that led to illness. This highlights the risks posed by undercooked poultry dishes, and shows that education of food handlers remains a priority.

Identification of the first erm(B)-positive Campylobacter jejuni and Campylobacter coli associated with novel multidrug resistance genomic islands in Australia.

OBJECTIVES: This report describes the first identification of two Campylobacter isolates harbouring erm(B) in Australia. METHODS: Two erm(B)-positive isolates, Campylobacter coli 18V1065H1 and Campylobacter jejuni 19W1001H1, were isolated from diarrhoeal faecal samples from two travellers who had recently returned from Southeast Asia. Isolates underwent whole-genome sequencing using an Illumina NextSeq system and were analysed with the Nullarbor pipeline. Antimicrobial resistance genes were identified using AMRFinderPlus and sequence types (STs) were determined by multilocus sequence typing and the PubMLST Campylobacter jejuni/coli typing scheme. RESULTS: Besideserm(B), C. jejuni 19W1001H1 possessed six other resistance genes [aad9, aadE, aph(3')-Illa, blaOXA-185, catA13 and tet(O)], the gyrA T86I mutation and the RE-CmeABC multidrug efflux pump variant. Campylobacter coli 18V1065H1 also possessed six resistance genes [aad9, aadE, aph(3')-IIIa, blaOXA-61, sat4 and tet(O)] in addition to erm(B); however, this isolate lacked genetic evidence for resistance to fluoroquinolones (no gyrA mutation). The erm(B) locus differed between isolates and neither was identical to previously identified erm(B) multidrug resistance genomic island (MDRGI) types. Both erm(B)-bearing isolates belonged to novel sequence types: ST9967 (C. jejuni 19W1001H1) and ST10161 (C. coli 18V1065H1). CONCLUSIONS: This study detected the presence oferm(B) in Campylobacter for the first time in Australia. This novel mechanism of macrolide resistance is a major concern both for human and animal health and warrants close surveillance as macrolides are often the drug of choice for treating campylobacteriosis. The erm(B) gene is associated with several MDRGIs and dissemination of this resistance mechanism will likely limit treatment options for Campylobacter infections.

Molecular characterization of Campylobacter spp. recovered from beef, chicken, lamb and pork products at retail in Australia.

Australian rates of campylobacteriosis are among the highest in developed countries, yet only limited work has been done to characterize Campylobacter spp. in Australian retail products. We performed whole genome sequencing (WGS) on 331 C. coli and 285 C. jejuni from retail chicken meat, as well as beef, chicken, lamb and pork offal (organs). Campylobacter isolates were highly diverse, with 113 sequence types (STs) including 38 novel STs, identified from 616 isolates. Genomic analysis suggests very low levels (2.3-15.3%) of resistance to aminoglycoside, beta-lactam, fluoroquinolone, macrolide and tetracycline antibiotics. A majority (>90%) of isolates (52/56) possessing the fluoroquinolone resistance-associated T86I mutation in the gyrA gene belonged to ST860, ST2083 or ST7323. The 44 pork offal isolates were highly diverse, representing 33 STs (11 novel STs) and harboured genes associated with resistance to aminoglycosides, lincosamides and macrolides not generally found in isolates from other sources. Prevalence of multidrug resistant genotypes was very low (<5%), but ten-fold higher in C. coli than C. jejuni. This study highlights that Campylobacter spp. from retail products in Australia are highly genotypically diverse and important differences in antimicrobial resistance exist between Campylobacter species and animal sources.

Prevalence of Campylobacter coli and Campylobacter jejuni in Retail Chicken, Beef, Lamb, and Pork Products in Three Australian States.

The aim of this study was to investigate the prevalence and distribution of Campylobacter species in a variety of fresh and frozen meat and offal products collected from retail outlets in New South Wales (NSW), Queensland (Qld), and Victoria (Vic). A total of 1,490 chicken, beef, lamb, and pork samples were collected from Australian supermarkets and butcher shops over a 2-year sampling period (October 2016 to October 2018). Campylobacter spp. were detected in 90% of chicken meat and 73% of chicken offal products (giblet and liver), with significantly lower prevalence in lamb (38%), pork (31%), and beef (14%) offal (kidney and liver). Although retail chicken meat was frequently contaminated with Campylobacter, the level of contamination was generally low. Where quantitative analysis was conducted, 98% of chicken meat samples, on average, had <10,000 CFU Campylobacter per carcass, with 10% <21 CFU per carcass. Campylobacter coli was the most frequently recovered species in chicken meat collected in NSW (53%) and Vic (56%) and in chicken offal collected in NSW (77%), Qld (59%), and Vic (58%). In beef, lamb, and pork offal, C. jejuni was generally the most common species (50 to 86%), with the exception of pork offal collected in NSW, where C. coli was more prevalent (69%). Campylobacter prevalence was significantly higher in fresh lamb (46%) and pork (31%) offal than in frozen offal (17 and 11%, respectively). For chicken, beef, and pork offal, the prevalence of Campylobacter spp. was significantly higher on delicatessen products compared with prepackaged products. This study demonstrated that meat and offal products are frequently contaminated with Campylobacter. However, the prevalence is markedly different in different meats, and the level of chicken meat portion contamination is generally low. By identifying the types of meat and offal products types that pose the greatest risk of Campylobacter infection to consumers, targeted control strategies can be developed.

Is penicillin and/or erythromycin resistance present in clinical isolates of group B streptococcus in our community?

Traditionally group B streptococcus (GBS) has not exhibited resistance to the antibiotics penicillin and erythromycin. Recently there are reports from North America whereby some GBS isolates have exhibited resistance to erythromycin. There have been no studies reported to date to determine whether this resistance trend is also occurring in the Australian population. Over a period of six months from January to June 1999, 250 GBS isolates were collected at the Royal Women's Hospital, Melbourne. Sensitivity to penicillin, erythromycin and vancomycin was determined by disk diffusion. Any isolates that had reduced zones to penicillin, vancomycin or erythromycin had minimum inhibitory concentrations (MIC) determined. No isolates had reduced susceptibility to penicillin or vancomycin. Of the 250 isolates, seven (2.8%, 95% CI = 1.1-5.6%) had resistant MICs to erythromycin of > 1.0 microg/mL. These preliminary data suggest that penicillin therapy is still an effective first-line antibiotic for intrapartum chemoprophylaxis and that erythromycin resistance is low in our population.