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Social network analysis has been postulated as a tool to study potential pathogen transmission in wildlife but is resource‐intensive to quantify. Networks based on bacterial genotypes have been proposed as a cost‐effective method for estimating social or transmission network based on the assumption that individuals in close contact will share commensal bacteria. However, the use of network analysis to study wild populations requires critical evaluation of the assumptions and parameters these models are founded on.We test (a) whether networks of commensal bacterial sharing are related to hosts' social associations and hence could act as a proxy for estimating transmission networks, (b) how the parameters chosen to define host associations and delineate bacterial genotypes impact inference and (c) whether these relationships change across time. We use stochastic simulations to evaluate how uncertainty in parameter choice affects network structure.We focused on a well‐studied population of eastern grey kangaroos (Macropus giganteus), from Sundown National Park, Australia. Using natural markings, each individual was identified and its associations with other kangaroos recorded through direct field observations over 2 years to construct social networks. Faecal samples were collected, Escherichia coli was cultured and genotyped using BOX‐PCR, and bacterial networks were constructed. Two individuals were connected in the bacterial network if they shared at least one E. coli genotype. We determined the capacity of bacterial networks to predict the observed social network structure in each year.We found little support for a relationship between social association and dyadic commensal bacterial similarity. Thresholds to determine host associations and similarity cut‐off values used to define E. coli genotypes had important ramifications for inferring links between individuals. In fact, we found that inferences can show opposite patterns based on the chosen thresholds. Moreover, no similarity in overall bacterial network structure was detected between years.Although empirical disease transmission data are often unavailable in wildlife populations, both bacterial networks and social networks have limitations in representing the mode of transmission of a pathogen. Our results suggest that caution is needed when designing such studies and interpreting results. [ABSTRACT FROM AUTHOR]

Since its initial isolation in Uganda in 1937 through the present, West Nile virus (WNV) has become an important cause of human and animal disease worldwide. WNV, an enveloped virus of the genus Flavivirus, is naturally maintained in an enzootic cycle between birds and mosquitoes, with occasional epizootic spillover causing disease in humans and horses. The mosquito vectors for WNV are widely distributed worldwide, and the known geographic range of WNV transmission and disease has continued to increase over the past 77 years. While most human infections with WNV are asymptomatic, severe neurological disease may develop resulting in long-term sequelae or death. Surveillance and preventive measures are an ongoing need to reduce the public health impact of WNV in areas with the potential for transmission. [ABSTRACT FROM AUTHOR]

Abstract: White tail disease (WTD) caused by Macrobrachium rosenbergii nodavirus (MrNV) has been found in the giant freshwater prawn (Macrobrachium rosenbergii) and has recently been the cause of high mortalities in many countries such as India, China, Taiwan and Thailand. In mid 2004, the index case of WTD in Australia presented in adult broodstock M. rosenbergii from Flinders River in western Queensland. In order to understand the phylogenetic relationship of the Australian recognizate of MrNV to other MrNV recognizates, the complete sequences of the Australian MrNV (RNA1 and RNA2) were determined. Nucleotide and phylogenetic analysis revealed that the Australian strain of MrNV (RNA1) was between 94% and 97% identical to Malaysian, the French West Indies, Chinese and the Thai recognizates. Also, the nucleotide sequence of the Australian MrNV (RNA2) was 92% identical to the French West Indies, Chinese and the Thai recognizates. The nucleotide comparison of protein B2 showed a different relationship between MrNV and fish nodaviruses. However, the phylogenetic tree of protein B2 determined that some fish nodaviruses are closely related to insect nodavirus. These results can be used to develop effective diagnostic tests and design specific RNA interference (RNAi) against protein B2 to control other nodaviruses in the future. [Copyright &y& Elsevier]

The World Health Organization recommends that the majority of water monitoring laboratories in the world test for E. coli daily since thermotolerant coliforms and E. coli are key indicators for risk assessment of recreational waters. Recently, we developed a new SNP method for typing E. coli strains, by which human-specific genotypes were identified. Here, we report the presence of these previously described specific SNP profiles in environmental water, sourced from the Coomera River, located in South East Queensland, Australia, over a period of two years. This study tested for the presence of human-specific E. coli to ascertain whether hydrologic and anthropogenic activity plays a key role in the pollution of the investigated watershed or whether the pollution is from other sources. We found six human-specific SNP profiles and one animal-specific SNP profile consistently across sampling sites and times. We have demonstrated that our SNP genotyping method is able to rapidly identify and characterize human- and animal-specific E. coli isolates in water sources. [ABSTRACT FROM AUTHOR]

A total of 250 mouse fecal specimens collected from crop farms in Queensland, Australia, were screened for the presence of Cryptosporidium spp. using PCR. Of these, 19 positives were detected and characterized at a number of loci, including the 18S rRNA gene, the acetyl coenzyme A gene, and the actin gene. Sequence and phylogenetic analyses identified two genotypes: mouse genotype I and a novel genotype (mouse genotype II), which is likely to be a valid species. Cryptosporidium parvuin, which is zoonotic, was not detected. The results of the study indicate that wild Australian mice that are not in close contact with livestock are probably not an important reservoir of Cryptosporidium infection for humans and other animals. [ABSTRACT FROM AUTHOR]

Aims: To characterise the resistome of a multi-drug resistant Klebsiella pneumoniae (Kp0003) isolated from an Australian traveller who was repatriated to a Sydney Metropolitan Hospital from Myanmar with possible prosthetic aortic valve infective endocarditis., Methods: Kp0003 was recovered from a blood culture of the patient and whole genome sequencing was performed. Read mapping and de novo assembly of reads facilitated in silico multi-locus sequence and plasmid replicon typing as well as the characterisation of antibiotic resistance genes and their genetic context. Conjugation experiments were also performed to assess the plasmid (and resistance gene) transferability and the effect on the antibiotic resistance phenotype., Results: Importantly, and of particular concern, the carbapenem-hydrolysing β-lactamase gene blaNDM-4 was identified on a conjugative IncX3 plasmid (pJEG027). In this respect, the blaNDM-4 genetic context is similar (at least to some extent) to what has previously been identified for blaNDM-1 and blaNDM-4-like variants., Conclusions: This study highlights the potential role that IncX3 plasmids have played in the emergence and dissemination of blaNDM-4-like variants worldwide and emphasises the importance of resistance gene surveillance., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)