Rowland Cobbold

Australia's large populations of feral and extensively farmed livestock pose challenges to implementing response plans in the event of an Emergency Animal Disease outbreak. This study aimed to determine if a “Destroy and Let Lie” approach to carcass disposal (leaving carcasses in situ to decompose naturally after field euthanasia) would reliably inactivate Foot and Mouth Disease virus (FMDV) and African Swine Fever virus (ASFV) under Australian conditions. Ninety‐five animals (24 each of cattle, sheep, goats and 23 pigs) were used across six trials, conducted in winter and summer, in three locations in Eastern Australia. After euthanasia, temperature and pH were measured at six internal anatomical sites hourly for 24 h, then less frequently for a further 24 h. Data were compared with published FMDV and ASFV inactivation thresholds to assess the likely effectiveness of field decomposition in reducing viral infectivity. Tissue pH levels generally declined for the first 6–12 h postmortem. Based on a pH threshold of <6, FMDV would be reliably inactivated in the thoracic and abdominal cavities and deep and superficial muscle sites. In contrast, no porcine tissues at any location in any season would provide inactivation of ASFV, based on a pH threshold of <3.9. “Destroy and Let Lie” appears to be a suitable approach to reduce risk of FMDV transmission from carcasses that cannot be disposed of using conventional means under Australian field conditions. This would not be the case for an ASF outbreak, where expected viral inactivation would be minimal.

Background/Objectives: Q-VAX vaccine, approved in Australia, prevents Q fever. However, individuals with prior Coxiella burnetii (Cb) infection have an increased risk of adverse reactions, requiring pre-vaccination screening by an intradermal hypersensitivity skin test for cell-mediated immune memory and a serological assay for anti-Cb antibodies. The week-long interval for skin test assessment limits efficient vaccination. This study evaluated a standardized interferon-γ release assay (IGRA) as a potential skin test alternative. Methods: Immune assays were compared in Australian populations with different incidences of prior Cb exposure. Cell-mediated immunity was assessed by the Q-VAX skin test and IGRA. Serological status was evaluated with established diagnostic assays. Hypothetical vaccine eligibility decisions using combined IGRA and serology results were compared with actual clinical decisions made using current guidelines. Results: All tests performed better in detecting prior infection than in detecting prior vaccination. Only the IGRA identified all individuals with a known history of Q fever. Agreement between the skin test and IGRA was limited. Moderate agreement was observed between hypothetical vaccine eligibility determinations based on IGRA plus serology results and actual clinical decisions. IGRA-positive but serology- and skin test-negative individuals received Q-VAX without clinically significant side effects, suggesting that elevated IGRA responses alone are not predictive of susceptibility to vaccine reactogenicity. Conclusions: The IGRA is not yet a suitable skin test replacement when assessing eligibility for Q fever vaccination, despite the significant limitations of the latter. We offer recommendations for designing future studies that might allow the development of appropriate guidelines for IGRA use in vaccine eligibility screening.

Antimicrobial resistance (AMR) is a growing global concern and poses a significant threat to public health. The emergence of multidrug-resistant organisms, including Escherichia coli, also presents a risk of transmission to humans through the food chain, including milk. This study aimed to investigate the prevalence of E. coli in raw milk in the Chattogram metropolitan area (CMA) of Bangladesh and their phenotypic and genotypic antimicrobial resistance patterns. A total of 450 raw cow milk samples were collected from 18 farms within the CMA. The isolation and identification of E. coli were performed following standard bacteriological methods. Antimicrobial susceptibility testing (AST) was conducted using the Kirby–Bauer disc diffusion method. Molecular detection of E. coli and antimicrobial resistance genes was performed using the Polymerase Chain Reaction (PCR). This study found 134 (29.77%) milk samples that tested positive for E. coli. Antimicrobial susceptibility testing (AST) revealed the highest resistance rates (69.40%) to be for ampicillin, amoxicillin–clavulanic acid, cephalothin, and cephalexin, with the lowest resistance (21.64%) being for norfloxacin. A significant correlation (r = 1) was observed between ciprofloxacin and ceftazidime resistance among the antimicrobials tested. All E. coli isolates were classified as multidrug-resistant (MDR), being resistant to three or more antimicrobial classes, with a multiple resistance index >0.2. PCR amplification showed that the bla_TEM gene had the highest prevalence (74.19%) among the ESBL and antimicrobial resistance genes tested. In contrast, the bla_CMY-1 gene had a lower prevalence (6.45%) among the ESBL genes, while the tetD gene had the lowest prevalence (2.9%) among the resistance genes tested. Positive correlations were observed between antimicrobial resistance and the presence of these resistance genes. This study emphasises the high prevalence of MDR E. coli in raw cow milk and its significant potential impact on public health. It underscores the urgent need for strategic interventions to effectively manage and mitigate AMR in the Bangladeshi dairy sector, focusing on the prudent use of antimicrobials and implementing enhanced AMR surveillance.

A healthy chicken's intestinal flora harbours a rich reservoir of Escherichia coli as part of the commensal microbiota. However, some strains, known as avian pathogenic E. coli (APEC), carry specific virulence genes (VGs) that enable them to invade and cause extraintestinal infections such as avian colibacillosis. Although several VG combinations have been identified, the pathogenic mechanisms associated with APEC are ill‐defined. The current study screened a subset of 88 E. coli isolates selected from 237 pre‐existing isolates obtained from commercial poultry flocks in Australia. The 88 isolates were selected based on their enterobacterial repetitive intergenic consensus (ERIC) and antimicrobial resistance (AMR) profiles and included 29 E. coli isolates cultured from chickens with colibacillosis (referred to as clinical E. coli or CEC) and 59 faecal E. coli (FEC) isolates cultured from clinically healthy chickens. The isolates were screened for the presence of 35 previously reported VGs. Of these, 34 were identified, with iucA not being detected. VGs focG, hlyA and sfa/foc were only detected in FEC isolates. Eight VGs had a prevalence of 90% or above in the CEC isolates. Specifically, astA (100%); feoB (96.6%); iutA, iss, ompT, iroN and hlyF (all 93.1%); and vat (89.7%). The prevalence of these were significantly lower in FEC isolates (astA 79.7%, feoB 77.9%, iutA 52.5%, iss 45.8%, ompT 50.9%, iroN 37.3%, hlyF 50.9% and vat 42.4%). The odds ratios that each of these eight VGs were more likely to be associated with CEC than FEC ranged from 7.8 to 21.9. These eight VGs may be used to better define APEC and diagnostically detect APEC in Australia. Further investigations are needed to identify the roles of these VGs in pathogenicity.

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This study aimed to estimate the antimicrobial resistance (AMR) patterns and tetracycline-resistant gene profiles of Escherichia coli (E. coli) from broiler meat and livers sourced from live bird markets (LBMs) and supermarkets (SMs) in Chattogram, Bangladesh. In total, 405 samples were collected from SMs and LBMs, comprising muscle (n = 215) and liver (n = 190) samples. Disc diffusion tests were used to determine antimicrobial susceptibility profiles. PCR was used to identify E. coli and tetracycline-resistant genes. Over half (57%) of the chicken product samples were positive for E. coli. The AMR profiling of these isolates showed that the highest prevalence of resistance was against sulphamethoxazole–trimethoprim (89%), followed by tetracycline (87%), ampicillin (83%), and ciprofloxacin (61%). Among the antimicrobials listed by the World Health Organization as critically important, E. coli isolates were found to be resistant to cephalexin (37%), gentamicin (32%), and colistin sulfate (21%). A large proportion of E. coli demonstrated multi-drug resistance (MDR). Most (84%) of the tetracycline-resistant isolates encoded tetA. Of the remaining isolates, 0.5% encoded tetC, 6.0% encoded two genes, and 3.6% of isolates were tetD, which was newly identified by this study in Bangladesh. Broiler products in Bangladesh are frequently contaminated with multi-drug-resistant E. coli, with differential carriage of tetracycline genes. The prevalence of tetracycline resistance among E. coli indicates a concern for poultry health and welfare regarding the management of colibacillosis. It also indicates growing public health risks of AMR among broiler-associated pathogens, which can be transferred to humans via the food chain. Appropriate control measures should be developed and implemented, focused on the rational use of antimicrobials in poultry farming systems, to mitigate risk from this drug-resistant zoonotic pathogen from foods of animal origin and to protect public health.

Avian pathogenic E. coli (APEC) can cause avian colibacillosis, an economically important disease that contributes to bird mortality and the high costs associated with prevention and treatment. Little is known about APEC in the context of Australian conditions. The current study aimed to estimate the prevalence of APEC and determine the risk factors associated with cloacal carriage of APEC among commercial healthy meat chickens in Queensland. Cloacal swabs were collected at slaughter from 400 healthy meat chickens (ten per farm) originating from 40 farms. A total of 2200 E. coli isolates were selected from cultured swabs and screened for the presence of five APEC-associated virulence genes (VGs). Farm-level data were collected using a questionnaire. Binominal general linear models were used to identify farm-level risk factors associated with bird-level APEC prevalence. Thirty-four per cent of the cultured E. coli isolates (n = 751) were classified as APEC, with all farms testing positive for APEC, and the overall bird-level prevalence of APEC was 63.0%. Higher APEC within-farm bird-level prevalence was positively associated with the usage of well water as a source of drinking water (OR = 6.2, 95% CI: 2.3, 16.5, p < 0.001); not having shower facilities available for farm visitors (OR = 3.6, 95% CI: 1.8, 7.1, p < 0.001); distances greater than 20 m between the car park and the poultry shed (OR = 2.2, 95% CI: 1.4, 3.4, p = 0.001); not applying water line disinfection after each flock cycle (OR = 2.2, 95% CI: 1.4, 3.5, p = 0.001); the presence of wild birds within 50 m of the poultry shed (OR = 2.3, 95% CI: 1.4, 3.7, p = 0.001). Chlorine combined with automatic drinking water filtration reduced within-farm bird-level APEC prevalence (OR = 0.07, 95% CI: 0.02, 0.34, p = 0.001). This study identified a number of important factors associated with APEC and showed that improving biosecurity and water treatments might reduce the prevalence of APEC. The notable high APEC prevalence on all farms requires further epidemiological investigations.

Veterinary paraprofessionals (VPPs) are engaged worldwide in animal health management, disease surveillance and food safety control. In many countries, particularly developing countries, VPPs are critical to national veterinary services provision. Until recently, there were no globally recognized training requirements for VPPs. Recognition of VPPs’ qualifications and roles, and requirements for registration, vary greatly between jurisdictions. To address these issues, the World Organisation for Animal Health (OIE) has developed competency and curricular guidelines for VPPs. A collaborative approach was essential to this mission. Extensive consultation with individuals and agencies representing various countries, animal health and veterinary sectors, and forms of expertise, was undertaken. Collaborative methods included the formation of a guidelines development ad hoc group whose diversity reflected project needs, the use of existing OIE Member Country data to understand roles of VPPs globally, conducting stakeholder surveys to collate VPP competency expectations and solicit feedback on draft guidelines, and in-country missions to validate draft curricular models. The initial deliverable from this work was publication of Competency Guidelines for VPPs. This document provides recommendations on the knowledge, skills, attitudes, and aptitudes that could be expected of VPPs following effective training. The companion document, OIE Curricular Guidelines for VPPs, provides recommendations on coursework structure and content to achieve these competencies. These guidelines will assist countries worldwide in more effectively training and qualifying VPPs so that they can contribute positively to the provision of veterinary services. Another potential impact is to catalyze the review of educational and regulatory standards regarding the respective work rights and activities of veterinarians and VPPs.

A World Organisation for Animal Health (OIE) Veterinary Education Twinning Project was established between the veterinary schools at Nong Lam University (NLU) in Ho Chi Minh City, Vietnam, and the University of Queensland, Gatton, Australia, as part of the scheme established to promote high-quality veterinary services through improved veterinary education. Included in the partnership’s primary aims were building the capacity of veterinary teaching staff with respect to general teaching practice and also in response to identified deficiency areas, and to develop outcome assessment processes. One challenge facing the project was the different approaches and experiences of teaching and learning for the faculty and students between the two widely different historical and cultural contexts of Australia and Vietnam. The project enhanced the pedagogy capability in NLU faculty and introduced student-focused approaches to teaching. The NLU staff involved in the project strongly embraced a student-centered approach to learning and case-based teaching in particular, adopting these strategies in their own teaching. An analysis of students’ approach to learning demonstrates that the majority preferred a deep approach to learning and that these students valued case studies, problem-solving exercises, and working in small groups during teaching sessions more than students who took a surface approach to learning. An improved recognition of the ways the Vietnamese students approach their learning in their home country will guide future teaching design, as well as give insight into the approaches to teaching for Southeast Asian students within the Australian veterinary science programs.

Effective infection control (IC) provides a safe environment for staff, clients and animals of veterinary practices by reducing the risk of nosocomial and zoonotic infections, which are associated with increased hospital stays, costs, morbidity and mortality. An equally important issue arising from nosocomial infection is the loss of trust between the client and the veterinary practice that has potential negative impacts on the veterinary practice in terms of economic risk and the well‐being of staff. Furthermore, an emerging and significant threat, in this context, is antimicrobial resistance. The aim of this systematic review was to critically review published reports that documented current IC practices and evaluated interventions to improve IC practices. A systematic literature search using ten databases to identify papers published over a 20‐year period (February 1996 to February 2016) was conducted for studies that met the inclusion criteria. Included studies were assessed using the PRISMA and STROBE‐Vet statements. A total of 14 of 1,615 identified studies met our inclusion criteria. Infection control practices included hand hygiene, sharps handling, environmental cleaning, personal protective equipment and personnel vaccination. Descriptive studies were the predominant research design for assessing IC compliance. Only three studies were interventions. Compliance with IC protocols was poor and only marginally increased with multimodal educational campaigns. There was significant variation in the implementation of IC by veterinary staff. Workplaces that had IC policies, management support and a staff member supporting their implementation were more likely to embrace good IC. Infection control data in veterinary practices were inconsistently reported and collected. Clearly defining IC and determining prevalence of these practices within the veterinary field is important given the limited research in this area. Further, developing and implementing educational campaigns for this sector is needed.