Rickettsia gravesii sp. nov.: a novel spotted fever group rickettsia in Western Australian Amblyomma triguttatum triguttatum ticks.

A rickettsial organism harboured by Amblyomma triguttatum ticks on Barrow Island, Western Australia, was discovered after reports of possible rickettsiosis among local workers. Subsequent isolation of this rickettsia (strain BWI-1) in cell culture and analysis of its phylogenetic, genotypic and phenotypic relationships with type strains of Rickettsia species with standing in nomenclature suggested that it was sufficiently divergent to warrant its classification as a new species. Multiple gene comparison of strain BWI-1 revealed degrees of sequence similarity with Rickettsia raoultii, its closest relative, of 99.

Evaluation of different chemical adjuvants on an avian influenza H6 DNA vaccine in chickens.

This study assessed the ability of three adjuvants (aluminium hydroxide, Essai (microparticle) and Phema (nanoparticle)) to enhance the immune response of chickens to an H6N2 avian influenza DNA vaccine. No haemagglutination inhibition antibody was detected following two intramuscular immunizations with the adjuvanted and non-adjuvanted pCAG-HAk vaccine, which has previously been shown to induce moderate H6 haemagglutinin antibody response in SPF chickens. Following virus challenge, neither the vaccinated group without adjuvant nor the Essai-adjuvanted group showed a statistically significant reduction in virus shedding in oropharyngeal and cloacal swabs compared with the naive control group.

The seroprevalence and factors associated with Ross river virus infection in western grey kangaroos (Macropus fuliginosus) in Western Australia.

A serosurvey was undertaken in 15 locations in the midwest to southwest of Western Australia (WA) to investigate the seroprevalence of Ross River virus (RRV) neutralizing antibodies and factors associated with infection in western grey kangaroos (Macropus fuliginosus). The estimated seroprevalence in 2632 kangaroo samples, using a serum neutralization test, was 43.9% (95% CI 42.

Cross-sectional study reveals high prevalence of Clostridium difficile non-PCR ribotype 078 strains in Australian veal calves at slaughter.

Recent reports in North America and Europe of Clostridium difficile being isolated from livestock and retail meats of bovine origin have raised concerns about the risk to public health. To assess the situation in Australia, we investigated the prevalence and genetic diversity of C. difficile in adult cattle and calves at slaughter.

Molecular characterization of Eimeria species in macropods.

A total of 597 faecal samples were collected from western grey kangaroos (Macropus fuliginosus), Euros (M. robustus), red kangaroos (M. rufus) in Western Australia and Eastern Grey Kangaroos (M.

Comparative sensitivity of four different cell lines for the isolation of Coxiella burnetii.

Coxiella burnetii is an obligate intracellular bacterium that causes the disease Q-fever. This is usually diagnosed by serology (immunofluorescence assay) and/or PCR detection of C. burnetii DNA.

Serologic evidence of human influenza virus infections in swine populations, Cambodia.

Background: This study was conducted from 2006 to 2010 and investigated the seroprevalence of influenza A viruses in Cambodian pigs, including human H1N1, H3N2, 2009 pandemic H1N1 (A(H1N1)pdm09), and highly pathogenic avian H5N1 influenza A viruses.

Methods: A total of 1147 sera obtained from pigs in Cambodia were tested by haemagglutination inhibition (HI) assays for antibody to human influenza A viruses along with both HI and microneutralization (MN) tests to assess immunological responses to H5N1 virus. The results were compared by year, age, and province.

Ultrasonic synthetic technique to manufacture a pHEMA nanopolymeric-based vaccine against the H6N2 avian influenza virus: a preliminary investigation.

This preliminary study investigated the use of poly (2-hydroxyethyl methacrylate) (pHEMA) nanoparticles for the delivery of the deoxyribonucleic acid (DNA) vaccine pCAG-HAk, which expresses the full length hemagglutinin (HA) gene of the avian influenza A/Eurasian coot/Western Australian/2727/1979 (H6N2) virus with a Kozak sequence which is in the form of a pCAGGS vector. The loaded and unloaded nanoparticles were characterized using field-emission scanning electron microscopy. Further characterizations of the nanoparticles were made using atomic force microscopy and dynamic light scattering, which was used to investigate particle size distributions.

Balanoposthitis, dyspareunia, and treponema in the critically endangered Gilbert's potoroo (Potorous gilbertii).

The Gilbert's potoroo (Potorous gilbertii) is one of Australia's most critically endangered mammals with a current estimated population of 70 individuals. Both the wild and captive populations have a long history of balanoposthitis with associated crusting, ulceration, and preputial discharge. We sought to identify the microbial species found in the discharge, determine their significance in causing balanoposthitis, and correlate these findings with reproductive success and survivorship.

Prevalence of Salmonella in fecal samples of western grey kangaroos (Macropus fuliginosus).

This is the first extensive study of the prevalence of naturally acquired Salmonella infection in wild-caught kangaroos in Australia. Given the close association between kangaroos, livestock, and humans and the growing popularity of kangaroo meat, it is important to identify epidemiologic factors associated with infection in these marsupials in order to minimize the risk of Salmonella transmission. The overall prevalence of fecal Salmonella in 645 western grey kangaroos (Macropus fuliginosus) sampled across 10 locations in Western Australia was 3.

Prevalence of Coxiella burnetii in western grey kangaroos (Macropus fuliginosus) in Western Australia.

We investigated the role of the western grey kangaroo (Macropus fuliginosus) in the maintenance and transmission of Coxiella burnetii in Western Australia. Sera from 1,017 kangaroos were tested using an indirect enzyme-linked immunosorbent assay (ELISA) for the presence of C. burnetii antibodies.

Detecting and measuring small numbers of viable Coxiella burnetii.

Coxiella burnetii is an acidophilic, intracellular bacterium that causes the human disease Q fever. In some studies, it is important to distinguish between viable and nonviable C. burnetii.

Strategies for improving the efficacy of a H6 subtype avian influenza DNA vaccine in chickens.

A low-pathogenicity avian influenza H6N2 virus was used to investigate approaches to improve DNA vaccine efficacy. The viral hemagglutinin (HA) gene or its chicken biased HA gene, incorporating a Kozak sequence, was cloned into a pCAGGS vector to produce the pCAG-HAk and pCAG-optiHAk constructs. Following two intramuscular injections, the seroconversion rate in vaccinated chickens with 10, 100 or 300 μg pCAG-HAk were 87.

Comparative susceptibility of Salmonella Typhimurium biofilms of different ages to disinfectants.

There is a general consensus that with increasing age a biofilm shows increased resistance to antimicrobials. In this study the susceptibility of 3-, 5- and 7-day-old Salmonella enterica serovar Typhimurium biofilms to disinfectants was evaluated. It was hypothesized that 7-day-old biofilms would be more resistant to disinfectants compared to 3- and 5-day-old biofilms.

Isolation of a novel Orientia species (O. chuto sp. nov.) from a patient infected in Dubai.

In July 2006, an Australian tourist returning from Dubai, in the United Arab Emirates (UAE), developed acute scrub typhus. Her signs and symptoms included fever, myalgia, headache, rash, and eschar. Orientia tsutsugamushi serology demonstrated a 4-fold rise in antibody titers in paired serum collections (1:512 to 1:8,192), with the sera reacting strongest against the Gilliam strain antigen.

Biological and genetic characterization of a low-pathogenicity avian influenza H6N2 virus originating from a healthy Eurasian coot.

Influenza A virus, A/Eurasian coot/Western Australia/2727/79 (H6N2), from an apparently healthy coot was characterized. This virus was able to grow on MDCK cells and produce a cytopathic effect in the absence of exogenous trypsin and was further characterized as a low-pathogenicity avian influenza virus, with an intravenous pathogenicity index of 0.15 and a (321)PQAETRG(328) motif at the cleavage site of the haemagglutinin gene.

A survey of Western Australian sheep, cattle and kangaroos to determine the prevalence of Coxiella burnetii.

The objective of this study was to investigate the prevalence of Coxiella burnetii in two domestic ruminant species (cattle and sheep) and the western grey kangaroo (Macropus fuliginosus) in Western Australia (WA). The IDEXX CHEKiT Q Fever ELISA and CFT were used to test sera from 50 sheep and 329 head of cattle for anti-C. burnetii antibodies and 343 kangaroo sera were tested using an indirect ELISA developed specifically for this study.

Novel rickettsia in ticks, Tasmania, Australia.

A novel rickettsia was detected in Ixodes tasmani ticks collected from Tasmanian devils. A total of 55% were positive for the citrate synthase gene by quantitative PCR. According to current criteria for rickettsia speciation, this new rickettsia qualifies as Candidatus Rickettsia tasmanensis, named after the location of its detection.

Hematological and serum biochemical reference values and cohort analysis in the Gilbert's potoroo (Potorous gilbertii).

Hematology and serum biochemistry blood values are tabulated for Australia's most critically endangered mammal, the Gilbert's potoroo (Potorous gilbertii). Significant differences were found between origin (captive or wild individuals) and age (subadult or adult) of animals. Sex, and presence or absence of Treponema infection, had minimal significance on blood values.

Pet birds and risks of respiratory disease in Australia: a review.

Objective: Exposure to birds has long been associated with disease in humans. Three respiratory diseases (psittacosis, allergic alveolitis and asthma) were reviewed in association with pet bird ownership with the aim to clarify the spectrum of avian-related respiratory illnesses.

Approach: Nineteen studies were selected for review based on recreational bird exposure in relation to psittacosis, allergic alveolitis and asthma.

Detection and identification of a novel spotted fever group rickettsia in Western Australia.

The extent to which rickettsiae are present in Western Australia (WA) is largely unknown. Recently there has been anecdotal evidence of a disease of unknown but possibly rickettsial origin occurring on Barrow Island, WA. Ticks were collected from people and screened using PCR.

Adhesion of Yersinia enterocolitica to non-cultured epithelial cells from pig and rabbit ilea.

A simple and reliable method was developed to isolate intact epithelial cells from pig and rabbit ilea and these were used to investigate the adhesion of Yersinia enterocolitica. Hydrophobic interaction was eliminated by treating the bacterial culture with 0.8 M tetramethyl urea (TMU).