Dynamics of Antimicrobial Resistance Carriage in Koalas (Phascolarctos Cinereus) and Pteropid Bats (Pteropus Poliocephalus) Before, During and After Wildfires

In the 2019-2020 summer, wildfires decimated the Australian bush environment and impacted wildlife species, including koalas (Phascolarctos cinereus) and grey headed flying fox pups (Pteropid bats, Pteropus poliocephalus). Consequently, hundreds of koalas and thousands of bat pups entered wildlife hospitals with fire-related injuries/illness, where some individuals received antimicrobial therapy. This study investigated the dynamics of antimicrobial resistance (AMR) in pre-fire, fire-affected and post-fire koalas and Pteropid bat pups. PCR and DNA sequencing were used to screen DNA samples extracted from faeces (koalas and bats) and cloacal swabs (koalas) for class 1 integrons, a genetic determinant of AMR, and to identify integron-associated antibiotic resistance genes. Class 1 integrons were detected in 25.5% of koalas (68 of 267) and 59.4% of bats (92 of 155). Integrons contained genes conferring resistance to aminoglycosides, trimethoprim and beta-lactams. Samples were also screened for blaTEM (beta-lactam) resistance genes, which were detected in 2.6% of koalas (7 of 267) and 25.2% of bats (39 of 155). Integron occurrence was significantly higher in fire-affected koalas in-care compared to wild pre-fire koalas (P < 0.0001). Integron and blaTEM occurrence were not significantly different in fire-affected bats compared to pre-fire bats (P > 0.05), however, their occurrence was significantly higher in fire-affected bats in-care compared to wild fire-affected bats (P < 0.0001 and P = 0.0488 respectively). The observed shifts of AMR dynamics in wildfire-impacted species flags the need for judicious antibiotic use when treating fire-affected wildlife to minimise unwanted selective pressure and negative treatment outcomes associated with carriage of resistance genes and antibiotic resistant bacteria.

Carriage of antibiotic resistance genes to treatments for chlamydial disease in koalas (Phascolarctos cinereus): A comparison of occurrence before and during catastrophic wildfires

Growing reports of diverse antibiotic resistance genes in wildlife species around the world symbolises the extent of this global One Health issue. The health of wildlife is threatened by antimicrobial resistance in situations where wildlife species develop disease and require antibiotics. Chlamydial disease is a key threat for koalas in Australia, with infected koalas frequently entering wildlife hospitals and requiring antibiotic therapy, typically with chloramphenicol or doxycycline. This study investigated the occurrence and diversity of target chloramphenicol and doxycycline resistance genes (cat and tet respectively) in koala urogenital and faecal microbiomes. DNA was extracted from 394 urogenital swabs and 91 faecal swabs collected from koalas in mainland Australia and on Kangaroo Island (KI) located 14 km off the mainland, before (n = 145) and during (n = 340) the 2019-2020 wildfires. PCR screening and DNA sequencing determined 9.9% of samples (95%CI: 7.5% to 12.9%) carried cat and/or tet genes, with the highest frequency in fire-affected KI koalas (16.8%) and the lowest in wild KI koalas sampled prior to fires (6.5%). The diversity of cat and tet was greater in fire-affected koalas (seven variants detected), compared to pre-fire koalas (two variants detected). Fire-affected koalas in care that received antibiotics had a significantly higher proportion (p < 0.05) of cat and/or tet genes (37.5%) compared to koalas that did not receive antibiotics (9.8%). Of the cat and/or tet positive mainland koalas, 50.0% were Chlamydia-positive by qPCR test. Chloramphenicol and doxycycline resistance genes in koala microbiomes may contribute to negative treatment outcomes for koalas receiving anti-chlamydial antibiotics. Thus a secondary outcome of wildfires is increased risk of acquisition of cat and tet genes in fire-affected koalas that enter care, potentially exacerbating the already significant threat of chlamydial disease on Australia's koalas. This study highlights the importance of considering impacts to wildlife health within the One Health approach to AMR and identifies a need for greater understanding of AMR ecology in wildlife.

Postpartum care: Discussions and counseling for the peripartum period

BACKGROUND

Traditionally, postpartum care is confined to inpatient care immediately post birth and one appointment approximately six weeks postpartum. Data supports a continuum of care model as best for the health of mother and baby. Despite most women having significant concerns about the postpartum period, these concerns are frequently incompletely addressed by providers. We surveyed prenatal and postpartum patients to understand their concerns and experiences discussing postpartum care with providers.

METHODS

Cross sectional surveys were administered between June 2019 and May 2021. Principal component analysis was used to show higher than average (positive) or lower than average (negative) conversations with providers about postpartum care examined by race, education, and parity. Chi squared tests were conducted to examine the significance of specific postpartum concerns.

RESULTS

421/450 patient surveys were analyzed, based on completion. Most patients were White (193), had post graduate degrees (188), privately insured (236), married (248), first time pregnant (152), and used doctors as their primary provider (267). Patients with lower education, higher parity and Black patients without postgraduate degrees reported higher than average postpartum counseling. Additionally, most patients expressed significant concerns about postpartum exhaustion (65.8%), breastfeeding (62.3%), pain (61.2%), physical activity (54.9%) and the baby blues (50.4%).

CONCLUSIONS

Postpartum concerns are incompletely and inconsistently addressed amongst patients based on race, parity, and education. A continuum of care approach, beginning in the third trimester, through the postpartum period, may provide better counseling to address all patients' concerns.

Transmission of Klebsiella strains and plasmids within and between grey-headed flying fox colonies

The grey-headed flying fox (Pteropus poliocephalus) is an endemic Australian fruit bat, known to carry zoonotic pathogens. We recently showed they harbour bacterial pathogen Klebsiella pneumoniae and closely related species in the K. pneumoniae species complex (KpSC); however, the dynamics of KpSC transmission and gene flow within flying fox colonies are poorly understood. High-resolution genome comparisons of 39 KpSC isolates from grey-headed flying foxes identified five putative strain transmission clusters (four intra- and one inter-colony). The instance of inter-colony strain transmission of K. africana was found between two flying fox populations within flying distance, indicating either direct or indirect transmission through a common food/water source. All 11 plasmids identified within the KpSC isolates showed 73% coverage (mean) and ≥95% identity to human-associated KpSC plasmids, indicating gene flow between human clinical and grey-headed flying fox isolates. Along with strain transmission, inter-species horizontal plasmid transmission between K. pneumoniae and Klebsiella africana was also identified within a flying fox colony. Finally, genome-scale metabolic models were generated to predict and compare substrate usage to previously published KpSC models, from human and environmental sources. These models indicated no distinction on the basis of metabolic capabilities. Instead, metabolic capabilities were consistent with population structure and ST/lineage.

Characterization of beta-lactam-resistant Escherichia coli from Australian fruit bats indicates anthropogenic origins

Antimicrobial-resistant Escherichia coli, particularly those resistant to critically important antimicrobials, are increasingly reported in wildlife. The dissemination of antimicrobial-resistant bacteria to wildlife indicates the far-reaching impact of selective pressures imposed by humans on bacteria through misuse of antimicrobials. The grey-headed flying fox (GHFF; Pteropus poliocephalus), a fruit bat endemic to eastern Australia, commonly inhabits urban environments and encounters human microbial pollution. To determine if GHFF have acquired human-associated bacteria, faecal samples from wild GHFF (n=287) and captive GHFF undergoing rehabilitation following illness or injury (n=31) were cultured to detect beta-lactam-resistant E. coli. Antimicrobial susceptibility testing, PCR and whole genome sequencing were used to determine phenotypic and genotypic antimicrobial resistance profiles, strain type and virulence factor profiles. Overall, 3.8 % of GHFF carried amoxicillin-resistant E. coli (wild 3.5 % and captive 6.5 %), with 38.5 % of the 13 GHFF E. coli isolates exhibiting multidrug resistance. Carbapenem (bla_NDM-5) and fluoroquinolone resistance were detected in one E. coli isolate, and two isolates were resistant to third-generation cephalosporins (bla_CTX-M-27 and ampC). Resistance to tetracycline and trimethoprim plus sulfamethoxazole were detected in 69.2% and 30.8 % of isolates respectively. Class 1 integrons, a genetic determinant of resistance, were detected in 38.5 % of isolates. Nine of the GHFF isolates (69.2 %) harboured extraintestinal virulence factors. Phylogenetic analysis placed the 13 GHFF isolates in lineages associated with humans and/or domestic animals. Three isolates were human-associated extraintestinal pathogenic E. coli (ST10 O89:H9, ST73 and ST394) and seven isolates belonged to lineages associated with extraintestinal disease in both humans and domestic animals (ST88, ST117, ST131, ST155 complex, ST398 and ST1850). This study provides evidence of anthropogenic multidrug-resistant and pathogenic E. coli transmission to wildlife, further demonstrating the necessity for incorporating wildlife surveillance within the One Health approach to managing antimicrobial resistance.

Into the sea: Antimicrobial resistance determinants in the microbiota of little penguins (Eudyptula minor)

Terrestrial and aquatic birds have been proposed as sentinels for the spread of antimicrobial resistant bacteria, but few species have been investigated specifically in the context of AMR in the marine ecosystem. This study contrasts the occurrence of class 1 integrons and associated antimicrobial resistance genes in wild and captive little penguins (Eudyptula minor), an Australian seabird with local population declines. PCR screening of faecal samples (n = 448) revealed a significant difference in the prevalence of class 1 integrons in wild and captive groups, 3.2% and 44.7% respectively, with genes that confer resistance to streptomycin, spectinomycin, trimethoprim and multidrug efflux pumps detected. Class 1 integrons were not detected in two clinically relevant bacterial species, Klebsiella pneumoniae or Escherichia coli, isolated from penguin faeces. The presence of class 1 integrons in the little penguin supports the use of marine birds as sentinels of AMR in marine environments.

Molecular characterization of Cryptosporidium and Giardia from the Tasmanian devil (Sarcophilus harrisii)

The Tasmanian devil (Sarcophilus harrisii) is a carnivorous marsupial found only in the wild in Tasmania, Australia. Tasmanian devils are classified as endangered and are currently threatened by devil facial tumour disease, a lethal transmissible cancer that has decimated the wild population in Tasmania. To prevent extinction of Tasmanian devils, conservation management was implemented in 2003 under the Save the Tasmanian Devil Program. This study aimed to assess if conservation management was altering the interactions between Tasmanian devils and their parasites. Molecular tools were used to investigate the prevalence and diversity of two protozoan parasites, Cryptosporidium and Giardia, in Tasmanian devils. A comparison of parasite prevalence between wild and captive Tasmanian devils showed that both Cryptosporidium and Giardia were significantly more prevalent in wild devils (p < 0.05); Cryptosporidium was identified in 37.9% of wild devils but only 10.7% of captive devils, while Giardia was identified in 24.1% of wild devils but only 0.82% of captive devils. Molecular analysis identified the presence of novel genotypes of both Cryptosporidium and Giardia. The novel Cryptosporidium genotype was 98.1% similar at the 18S rDNA to Cryptosporidium varanii (syn. C. saurophilum) with additional samples identified as C. fayeri, C. muris, and C. galli. Two novel Giardia genotypes, TD genotype 1 and TD genotype 2, were similar to G. duodenalis from dogs (94.4%) and a Giardia assemblage A isolate from humans (86.9%). Giardia duodenalis BIV, a zoonotic genotype of Giardia, was also identified in a single captive Tasmanian devil. These findings suggest that conservation management may be altering host-parasite interactions in the Tasmanian devil, and the presence of G. duodenalis BIV in a captive devil points to possible human-devil parasite transmission.

The environmental impact of sewage and wastewater outfalls in Antarctica: An example from Davis station, East Antarctica

We present a comprehensive scientific assessment of the environmental impacts of an Antarctic wastewater ocean outfall, at Davis station in East Antarctica. We assessed the effectiveness of current wastewater treatment and disposal requirements under the Protocol on Environmental Protection to the Antarctic Treaty. Macerated wastewater has been discharged from an outfall at Davis since the failure of the secondary treatment plant in 2005. Water, sediment and wildlife were tested for presence of human enteric bacteria and antibiotic resistance mechanisms. Epibiotic and sediment macrofaunal communities were tested for differences between sites near the outfall and controls. Local fish were examined for evidence of histopathological abnormalities. Sediments, fish and gastropods were tested for uptake of sewage as measured by stable isotopes of N and C. Escherichia coli carrying antibiotic resistance determinants were found in water, sediments and wildlife (the filter feeding bivalve Laternula eliptica). Fish (Trematomus bernacchii) within close proximity to the outfall had significantly more severe and greater occurrences of histopathological abnormalities than at controls, consistent with exposure to sewage. There was significant enrichment of ¹⁵N in T. bernacchii and the predatory gastropod Neobuccinum eatoni around the outfall, providing evidence of uptake of sewage. There were significant differences between epibiotic and sediment macrofaunal communities at control and outfall sites (<1.5 km), when sites were separated into groups of similar habitat types. Benthic community composition was also strongly related to habitat and environmental drivers such as sea ice. The combined evidence indicated that the discharge of wastewater from the Davis outfall is causing environmental impacts. These findings suggest that conditions in Antarctic coastal locations, such as Davis, are unlikely to be conducive to initial dilution and rapid dispersal of wastewater as required under the Protocol on Environmental Protection to the Antarctic Treaty. Current minimum requirements for wastewater treatment and disposal in Antarctica are insufficient to ameliorate these risks and are likely to lead to accumulation of contaminants and introduction of non-native microbes and associated genetic elements. This new understanding suggests that modernised approaches to the treatment and disposal of wastewater are required in Antarctica. The most effective solution is advanced levels of wastewater treatment, which are now possible, feasible and a high priority for installation. As a direct outcome of the study, a new advanced treatment system is being installed at Davis, effectively avoiding environmental risks.

Escherichia coli out in the cold: Dissemination of human-derived bacteria into the Antarctic microbiome

Discharge of untreated sewage into Antarctic environments presents a risk of introducing non-native microorganisms, but until now, adverse consequences have not been conclusively identified. Here we show that sewage disposal introduces human derived Escherichia coli carrying mobile genetic elements and virulence traits with the potential to affect the diversity and evolution of native Antarctic microbial communities. We compared E. coli recovered from environmental and animal sources in Antarctica to a reference collection of E. coli from humans and non-Antarctic animals. The distribution of phylogenetic groups and frequency of 11 virulence factors amongst the Antarctic isolates were characteristic of E. coli strains more commonly associated with humans. The rapidly emerging E. coli ST131 and ST95 clones were found amongst the Antarctic isolates, and ST95 was the predominant E. coli recovered from Weddell seals. Class 1 integrons were found in 15% of the Antarctic E. coli with 4 of 5 identified gene cassette arrays containing antibiotic resistance genes matching those common in clinical contexts. Disposing untreated sewage into the Antarctic environment does disseminate non-native microorganisms, but the extent of this impact and implications for Antarctic ecosystem health are, as yet, poorly understood.

Giardiasis in NSW: Identification of Giardia duodenalis assemblages contributing to human and cattle cases, and an epidemiological assessment of sporadic human giardiasis

Two genetic assemblages (A and B) of the protozoan parasite species, Giardia duodenalis, infect humans, domestic animals and wildlife. In New South Wales, Australia, over 2000 sporadic human giardiasis cases are reported annually, but parasite sources and links between sporadic cases are unknown. This study describes G. duodenalis assemblages contributing to human and cattle cases in NSW, and examines demographic, spatial, and temporal distributions of NSW human infections and G. duodenalis assemblages. Genotyping by PCR-restriction fragment length polymorphism of the glutamate dehydrogenase (gdh) gene identified G. duodenalis assemblage B as the most common (86%) cause of infection among human cases (n=165). Approximately 37% of cattle DNA samples were PCR positive (18S rRNA, gdh), and G. duodenalis assemblages E (69%) or B (31%) were identified from these samples. Human assemblage A was more common among older age groups, and seasonality in the geographic dispersal of human assemblage A was observed. The results of this study indicate G. duodenalis assemblage B is highly prevalent among humans in NSW, and the potential for cross-species transmission exists between humans and cattle in this region. Spatio-temporal and demographic distributions of human assemblage A and B are highlighted, and risk factors associated with these dispersal patterns warrants further research.

Colony Location and Captivity Influence the Gut Microbial Community Composition of the Australian Sea Lion (Neophoca cinerea)

Gut microbiota play an important role in maintenance of mammalian metabolism and immune system regulation, and disturbances to this community can have adverse impacts on animal health. To better understand the composition of gut microbiota in marine mammals, fecal bacterial communities of the Australian sea lion (Neophoca cinerea), an endangered pinniped with localized distribution, were examined. A comparison of samples from individuals across 11 wild colonies in South and Western Australia and three Australian captive populations showed five dominant bacterial phyla: Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Fusobacteria The phylum Firmicutes was dominant in both wild (76.4% ± 4.73%) and captive animals (61.4% ± 10.8%), while Proteobacteria contributed more to captive (29.3% ± 11.5%) than to wild (10.6% ± 3.43%) fecal communities. Qualitative differences were observed between fecal communities from wild and captive animals based on principal-coordinate analysis. SIMPER (similarity percentage procedure) analyses indicated that operational taxonomic units (OTU) from the bacterial families Clostridiaceae and Ruminococcaceae were more abundant in wild than in captive animals and contributed most to the average dissimilarity between groups (SIMPER contributions of 19.1% and 10.9%, respectively). Differences in the biological environment, the foraging site fidelity, and anthropogenic impacts may provide various opportunities for unique microbial establishment in Australian sea lions. As anthropogenic disturbances to marine mammals are likely to increase, understanding the potential for such disturbances to impact microbial community compositions and subsequently affect animal health will be beneficial for management of these vulnerable species.

IMPORTANCE

The Australian sea lion is an endangered species for which there is currently little information regarding disease and microbial ecology. In this work, we present an in-depth study of the fecal microbiota of a large number of Australian sea lions from geographically diverse wild and captive populations. Colony location and captivity were found to influence the gut microbial community compositions of these animals. Our findings significantly extend the baseline knowledge of marine mammal gut microbiome composition and variability.

Evaluation of next generation sequencing for the analysis of Eimeria communities in wildlife

Next-generation sequencing (NGS) techniques are well-established for studying bacterial communities but not yet for microbial eukaryotes. Parasite communities remain poorly studied, due in part to the lack of reliable and accessible molecular methods to analyse eukaryotic communities. We aimed to develop and evaluate a methodology to analyse communities of the protozoan parasite Eimeria from populations of the Australian marsupial Petrogale penicillata (brush-tailed rock-wallaby) using NGS. An oocyst purification method for small sample sizes and polymerase chain reaction (PCR) protocol for the 18S rRNA locus targeting Eimeria was developed and optimised prior to sequencing on the Illumina MiSeq platform. A data analysis approach was developed by modifying methods from bacterial metagenomics and utilising existing Eimeria sequences in GenBank. Operational taxonomic unit (OTU) assignment at a high similarity threshold (97%) was more accurate at assigning Eimeria contigs into Eimeria OTUs but at a lower threshold (95%) there was greater resolution between OTU consensus sequences. The assessment of two amplification PCR methods prior to Illumina MiSeq, single and nested PCR, determined that single PCR was more sensitive to Eimeria as more Eimeria OTUs were detected in single amplicons. We have developed a simple and cost-effective approach to a data analysis pipeline for community analysis of eukaryotic organisms using Eimeria communities as a model. The pipeline provides a basis for evaluation using other eukaryotic organisms and potential for diverse community analysis studies.

Biodiversity of parasite assemblages in the genus Petrogale and its relation to the phylogeny and biogeography of their hosts

Parasites form an integral part of overall biodiversity although they are often overlooked in conservation management, where emphasis is primarily directed towards the host. Parasites are often highly specialised to particular hosts, and thus may be just as threatened as the host they inhabit. For many of Australia’s wildlife species, little is known about their associated parasite communities. To begin to address this knowledge gap, we documented the parasite fauna described in the genetically diverse marsupial genus Petrogale, which contains seven species of conservation concern. The literature evaluation showed parasites of Petrogale to be highly diverse, with 17 species of protozoa, 8 species of cestodes, 102 species of nematodes and 30 species of ectoparasites identified in 16 of 17 Petrogale host species. A comparison of the parasite communities amongst Petrogale host species indicated a highly significant correlation between the parasite community similarity, and the phylogeny (P = 0.008) and biogeography (P = 0.0001) of their Petrogale hosts, suggesting high host specificity within their associated parasite assemblages. Five Petrogale species have established species recovery programs and their parasite communities should also be considered threatened, and management of parasite diversity required as part of these conservation programs.

Investigation into potential transmission sources of Giardia duodenalis in a threatened marsupial (Petrogale penicillata)

Assemblages of the protozoan parasite Giardia duodenalis common in humans and domestic species are increasingly identified in wildlife species, raising concern about the spill-over of pathogens from humans and domestic animals into wildlife. Here, the identity and prevalence of G. duodenalis in populations of a threatened marsupial, the brush-tailed rock-wallaby (Petrogale penicillata), was investigated. Identification of G. duodenalis isolates, across three loci (18S rRNA, β-giardin and gdh), from rock-wallaby fecal samples (n = 318) identified an overall detection rate of 6.3%. No significant difference in G. duodenalis detection was found among captive, wild and supplemented populations. Isolates were assigned to the zoonotic assemblages A and B at 18S rRNA, with sub-assemblages AI and BIV identified at the β-giardin and gdh loci, respectively. Assemblages AI and BIV have previously been identified in human clinical cases, but also in domestic animals and wildlife. The identification of these assemblages in brush-tailed rock-wallabies suggests there are transmission routes of G. duodenalis from humans or other animals to Australian wildlife, both in captivity and in the wild.

Parasitic nematode communities of the red kangaroo, Macropus rufus: richness and structuring in captive systems

Captive management practices have the potential to drastically alter pre-existing host-parasite relationships. This can have profound implications for the health and productivity of threatened species in captivity, even in the absence of clinical symptoms of disease. Maximising the success of captive breeding programmes requires a detailed knowledge of anthropogenic influences on the structure of parasite assemblages in captive systems. In this study, we employed two high-throughput molecular techniques to characterise the parasitic nematode (suborder Strongylida) communities of the red kangaroo, Macropus rufus, across seven captive sites. The first was terminal restriction fragment length polymorphism (T-RFLP) analysis of a region of rDNA encompassing the internal transcribed spacers 1 (ITS1), the 5.8S rRNA gene and the internal transcribed spacer 2 (ITS2). The second was Illumina MiSeq next-generation sequencing of the ITS2 region. The prevalence, intensity of infection, taxonomic composition and comparative structure of strongylid nematode assemblages was assessed at each location. Prevalence (P = <0.001) and mean infection intensity (df = 6, F = 17.494, P = <0.001) differed significantly between the seven captive sites. Significant levels of parasite community structure were observed (ANOSIM, P = 0.01), with most of the variation being distributed within, rather than between, captive sites. The range of nematode taxa that occurred in captive red kangaroos appeared to differ from that of wild conspecifics, with representatives of the genus Cloacina, a dominant nematode parasite of the macropodid forestomach, being detected at only two of the seven study sites. This study also provides the first evidence for the presence of the genus Trichostrongylus in a macropodid marsupial. Our results demonstrate that contemporary species management practices may exert a profound influence on the structure of parasite communities in captive systems.

Prevalence and Molecular Identification of Nematode and Dipteran Parasites in an Australian Alpine Grasshopper (Kosciuscola tristis)

In alpine Australia, Orthoptera are abundant, dominant herbivores, important prey species, and hosts for parasites and parasitoids. Despite the central role of orthopterans in alpine ecosystems, the impact of parasites on orthopteran populations is under-explored. In this study we describe the relationship between parasite prevalence and host sex, body size and year of collection. We accessed an existing, preserved collection of 640 Kosciuscola tristis collected from across its range between 2007 and 2011. Upon dissection we collected juvenile parasites and used molecular tools to identify them to three families (Nematoda; Mermithidae, and Arthropoda: Diptera: Tachinidae and Sarcophagidae). The prevalence of nematodes ranged from 3.5% to 25.0% and dipterans from 2.4% to 20.0%. Contrary to predictions, we found no associations between parasite prevalence and grasshopper sex or size. Although there was an association between prevalence of both nematodes and dipterans with year of collection, this is likely driven by a small sample size in the first year. Our results provide a foundation for future studies into parasite prevalence within the alpine environment and the abiotic factors that might influence these associations.

Diversity of Cryptosporidium in brush-tailed rock-wallabies (Petrogale penicillata) managed within a species recovery programme

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Cryptosporidium diversity was investigated in a BTRW as part of a recovery programme.

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Faecal samples from captive bred, supplemented and wild wallabies were screened.

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Cryptosporidium isolates were identified at three gene loci using PCR.

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Diverse species of Cryptosporidium were identified across populations.

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Both specific, C. fayeri, and broad host species, C. meleagridis, were identified.

Host–parasite relationships are likely to be impacted by conservation management practices, potentially increasing the susceptibility of wildlife to emerging disease. Cryptosporidium, a parasitic protozoan genus comprising host-adapted and host-specific species, was used as an indicator of parasite movement between populations of a threatened marsupial, the brush-tailed rock-wallaby (Petrogale penicillata). PCR screening of faecal samples (n = 324) from seven wallaby populations across New South Wales, identified Cryptosporidium in 7.1% of samples. The sampled populations were characterised as captive, supplemented and wild populations. No significant difference was found in Cryptosporidium detection between each of the three population categories. The positive samples, detected using 18S rRNA screening, were amplified using the actin and gp60 loci. Multi-locus sequence analysis revealed the presence of Cryptosporidium fayeri, a marsupial-specific species, and C. meleagridis, which has a broad host range, in samples from the three population categories. Cryptosporidium meleagridis has not been previously reported in marsupials and hence the pathogenicity of this species to brush-tailed rock-wallabies is unknown. Based on these findings, we recommend further study into Cryptosporidium in animals undergoing conservation management, as well as surveying wild animals in release areas, to further understand the diversity and epidemiology of this parasite in threatened wildlife.

Genetics and infection dynamics of Paratrichosoma sp in farmed saltwater crocodiles (Crocodylus porosus)

Paratrichosoma-associated helminthiasis has been identified in saltwater crocodiles under intensive farming conditions. The development of sustainable integrated management practices is dependent on a detailed understanding of Paratrichosoma population genetics and infection dynamics. This study investigated the genetic relationships of Paratrichosoma sp in a population of commercially farmed saltwater crocodiles, Crocodylus porosus, in northern Australia. 18S ribosomal RNA gene sequence data were obtained from Paratrichosoma sp eggs present in the epidermis of infected animals. A high level of genetic diversity was distributed within the Paratrichosoma sp population (241 variable positions in the 1094 bp alignment), indicating an accelerated rate of nucleotide base-pair substitutions in this genus of nematodes. Several possible environmental correlates of the incidence and intensity of helminthiasis, including season, rainfall, and mean monthly temperature, were investigated by visual inspection of crocodile skins. Stepwise logistic regression revealed a significant negative linear relationship (P = 0.011, R (2) = 32.69 %) between mean monthly rainfall and the incidence of monthly Paratrichosoma-associated helminthiasis. Variation in the severity of Paratrichosoma-associated helminthiasis could not be explained by any of the independent environmental variables included within an ordinal regression analysis. The large genetic diversity in these nematodes indicates a high probability of anthelmintic resistant alleles occurring in the population. We discuss how the spread of these alleles may be mitigated by adopting targeted treatment protocols.

Distribution of Giardia duodenalis assemblages A and B among children living in a remote indigenous community of the Northern Territory, Australia

Giardiasis is a communicable gastrointestinal disease caused by Giardia duodenalis and two genetic assemblages, A and B, cause human infection. In remote Indigenous communities of Australia, giardiasis is highly prevalent among children but disease transmission is poorly understood. This study investigated the prevalence of Giardia and genetic subtypes contributing to human disease in a remote Indigenous community, in the Northern Territory of Australia. Eighty-seven faecal samples were collected from 74 children (<15 years) over an 18 month period, and the distribution of positive cases relative to participant age and gender were examined. Screening by microscopy and 18S rRNA PCR amplification showed 66.7% (58/87) of faecal samples were positive for Giardia. Both males and females were equally affected and high detection rates were obtained for participants aged 0-<5 years and 5-<10 years (66.0 and 60.0% respectively). For 58.6% of the positive samples, Giardia was only detected by 18S rRNA PCR. Approximately 75% of cases were assemblage B, and subassemblage analyses using terminal restriction fragment length polymorphism of the glutamate dehydrogenase gene demonstrated that a variety of genetic variants were present. The high proportion of positive cases that were not detectable by microscopy, and dominance of assemblage B cases highlights the need for further research in this community, to assess the contribution of Giardia to chronic gastrointestinal disease among children, and to understand conditions conductive to assemblage B transmission.

Towards the molecular characterisation of parasitic nematode assemblages: an evaluation of terminal-restriction fragment length polymorphism (T-RFLP) analysis

Identifying factors which regulate temporal and regional structuring within parasite assemblages requires the development of non-invasive techniques which facilitate both the rapid discrimination of individual parasites and the capacity to monitor entire parasite communities across time and space. To this end, we have developed and evaluated a rapid fluorescence-based method, terminal restriction fragment length polymorphism (T-RFLP) analysis, for the characterisation of parasitic nematode assemblages in macropodid marsupials. The accuracy with which T-RFLP was capable of distinguishing between the constituent taxa of a parasite community was assessed by comparing sequence data from two loci (the ITS+ region of nuclear ribosomal DNA and the mitochondrial CO1) across ∼20 species of nematodes (suborder Strongylida). Our results demonstrate that with fluorescent labelling of the forward and reverse terminal restriction fragments (T-RFs) of the ITS+ region, the restriction enzyme Hinf1 was capable of generating species specific T-RFLP profiles. A notable exception was within the genus Cloacina, in which closely related species often shared identical T-RFs. This may be a consequence of the group's comparatively recent evolutionary radiation. While the CO1 displayed higher sequence diversity than the ITS+, the subsequent T-RFLP profiles were taxonomically inconsistent and could not be used to further differentiate species within Cloacina. Additionally, several of the ITS+ derived T-RFLP profiles exhibited unexpected secondary peaks, possibly as a consequence of the restriction enzymes inability to cleave partially single stranded amplicons. These data suggest that the question of T-RFLPs utility in monitoring parasite communities cannot be addressed without considering the ecology and unique evolutionary history of the constituent taxa.

Cryptosporidium from a free-ranging marsupial host: bandicoots in urban Australia

Expansion of human settlement has increased the interface between people and bandicoots with implications for the emergence and spread of zoonotic parasites. The host status of bandicoots inhabiting suburban areas and their potential role in Cryptosporidium transmission remains unresolved. Our study aimed to determine the prevalence and identity of Cryptosporidium in two sympatric bandicoot species. Cryptosporidium signatures were detected in twelve bandicoot faecal samples (n=98) through amplification of the 18S rRNA. Phylogenetic inference placed the isolates in a clade with Cryptosporidium parvum, a species with a broad host range and zoonotic potential, or loosely related to Cryptosporidium hominis. However, the identity of the bandicoot isolates was not fully resolved and whether they were infected or simply passively transmitting oocysts is unknown. This study revealed that free-ranging bandicoots of northern Sydney were shedding Cryptosporidium oocysts at a prevalence of 12.2% (95% CI [6.76, 20.8]), similar to marsupial species that act as reservoirs for Cryptosporidium. Our findings expand the range of hosts known to shed Cryptosporidium in urban areas.

Into the wild: dissemination of antibiotic resistance determinants via a species recovery program

Management strategies associated with captive breeding of endangered species can establish opportunities for transfer of pathogens and genetic elements between human and animal microbiomes. The class 1 integron is a mobile genetic element associated with clinical antibiotic resistance in gram-negative bacteria. We examined the gut microbiota of endangered brush-tail rock wallabies Petrogale penicillata to determine if they carried class 1 integrons. No integrons were detected in 65 animals from five wild populations. In contrast, class 1 integrons were detected in 48% of fecal samples from captive wallabies. The integrons contained diverse cassette arrays that encoded resistance to streptomycin, spectinomycin, and trimethoprim. Evidence suggested that captive wallabies had acquired typical class 1 integrons on a number of independent occasions, and had done so in the absence of strong selection afforded by antibiotic therapy. Sufficient numbers of bacteria containing diverse class 1 integrons must have been present in the general environment occupied by the wallabies to account for this acquisition. The captive wallabies have now been released, in an attempt to bolster wild populations of the species. Consequently, they can potentially spread resistance integrons into wild wallabies and into new environments. This finding highlights the potential for genes and pathogens from human sources to be acquired during captive breeding and to be unwittingly spread to other populations.

Pinning down a polymorphic parasite: new genetic and morphological descriptions of Eimeria macropodis from the Tammar wallaby (Macropus eugenii)

Identification of the protozoan parasite, Eimeria has traditionally relied on oocyst morphology, host range and life-cycle attributes. However, it is increasingly recognized that Eimeria species can vary in size and shape across their host range, an attribute known as 'polymorphism' that presents a unique challenge for identification. Advances in molecular tools hold promise for characterising Eimeria that may otherwise be misclassified based on morphology. Our study used morphologic and molecular traits of the oocyst life stage to identify a polymorphic parasite, Eimeria macropodis in a captive Tammar wallaby (Macropus eugenii) population in Australia. Molecular characterization highlighted the need to use multiple genetic markers (18S SSU and cytochrome c oxidase subunit I) to accurately identify E. macropodis owing to heterozygous alleles at the 18S SSU locus. This study provided an opportunity to assess the utility and shortcomings of morphologic and molecular techniques for 'pinning down' a polymorphic species. Moreover, our study was able to place E. macropodis in an evolutionary context and enhance resolution of the under-studied marsupial clade.

Pattern of maternal circulating CRH in laboratory-housed squirrel and owl monkeys

The anthropoid primate placenta appears to be unique in producing corticotropin-releasing hormone (CRH). Placental CRH is involved in an endocrine circuit key to the production of estrogens during pregnancy. CRH induces cortisol production by the maternal and fetal adrenal glands, leading to further placental CRH production. CRH also stimulates the fetal adrenal glands to produce dehydroepiandrostendione sulfate (DHEAS), which the placenta converts into estrogens. There are at least two patterns of maternal circulating CRH across gestation among anthropoids. Monkeys examined to date (Papio and Callithrix) have an early-to-mid gestational peak of circulating CRH, followed by a steady decline to a plateau level, with a possible rise near parturition. In contrast, humans and great apes have an exponential rise in circulating CRH peaking at parturition. To further document and compare patterns of maternal circulating CRH in anthropoid primates, we collected monthly blood samples from 14 squirrel monkeys (Saimiri boliviensis) and ten owl monkeys (Aotus nancymaae) during pregnancy. CRH immunoreactivity was measured from extracted plasma by using solid-phase radioimmunoassay. Both squirrel and owl monkeys displayed a mid-gestational peak in circulating CRH: days 45-65 of the 152-day gestation for squirrel monkeys (mean±SEM CRH=2,694±276 pg/ml) and days 60-80 of the 133-day gestation for owl monkeys (9,871±974 pg/ml). In squirrel monkeys, circulating CRH declined to 36% of mean peak value by 2 weeks before parturition and then appeared to increase; the best model for circulating CRH over gestation in squirrel monkeys was a cubic function, similar to previous results for baboons and marmosets. In owl monkeys, circulating CRH appeared to reach plateau with no subsequent significant decline approaching parturition, although a cubic function was the best fit. This study provides additional evidence for a mid-gestational peak of maternal circulating CRH in ancestral anthropoids that has been lost in the hominoid lineage.

Eimeria trichosuri: phylogenetic position of a marsupial coccidium, based on 18S rDNA sequences

Phylogenetic analysis of the genus Eimeria suggests that parasite and host have coevolved over broad evolutionary timescales. Here we extend this analysis by determining the 18S rDNA gene sequence of the marsupial coccidium, Eimeria trichosuri, and assessing its phylogenetic position relative to Eimeria from birds, reptiles and placental mammals. This analysis placed E. trichosuri clones in a clade that diverged before the major clade comprising species from placental mammals. The position of E.trichosuri is consistent with host phylogeny where marsupials represent an ancient evolutionary line that predates the placental mammal line.

Cryptosporidium fayeri: diversity within the GP60 locus of isolates from different marsupial hosts

The highly polymorphic 60 kDa glycoprotein (GP60) of Cryptosporidium is an important tool for investigating the epidemiology of this parasite. Characterization of the GP60 gene has only been performed for 3 of the 20 known Cryptosporidium species, and has already enabled sub-typing and source tracking of species with human significance. We have characterised a fourth species, Cryptosporidium fayeri, at the GP60 locus using isolates (n=26) from different marsupial hosts to assess the diversity of GP60 within this species. The analysis demonstrated that C. fayeri isolates could be assigned to 6 subtypes which were associated with host species and locality. The intra-species diversity for the host-adapted C. fayeri was less than the diversity for human pathogenic species suggesting that the GP60 locus is under less selective pressure in these than host-adapted species.

Closed-tube DNA extraction using a thermostable proteinase is highly sensitive, capable of single parasite detection

Current DNA extraction methods for parasites are labour-intensive and usually involve several steps, increasing the potential for cross-contamination. We describe here a closed-tube DNA extraction procedure based upon the use of a thermostable proteinase that enabled sensitive amplification of target loci from parasites from diverse lineages including Apicomplexa, Sarcomastgophora and Nematoda. Moreover, this procedure is not subject to cross-contamination and is readily adaptable to automation.

Deglutitive laryngeal closure in stroke patients

BACKGROUND

Dysphagia has been reported in up to 70% of patients with stroke, predisposing them to aspiration and pneumonia. Despite this, the mechanism for aspiration remains unclear.

AIMS

To determine the relationship between bolus flow and laryngeal closure during swallowing in patients with stroke and to examine the sensorimotor mechanisms leading to aspiration.

METHODS

Measures of swallowing and bolus flow were taken from digital videofluoroscopic images in 90 patients with stroke and 50 healthy adults, after repeated volitional swallows of controlled volumes of thin liquid. Aspiration was assessed using a validated Penetration-Aspiration Scale. Oral sensation was also measured by electrical stimulation at the faucial pillars.

RESULTS

After stroke, laryngeal ascent was delayed (mean (standard deviation (SD)) 0.31 (0.06) s, p<0.001), resulting in prolongation of pharyngeal transit time (1.17 (0.07) s, p<0.001) without a concomitant increase in laryngeal closure duration (0.84 (0.04) s, p = 0.9). The delay in laryngeal elevation correlated with both the severity of aspiration (r = 0.5, p<0.001) and oral sensation (r = 0.5, p<0.001).

CONCLUSIONS

After stroke, duration of laryngeal delay and degree of sensory deficit are associated with the severity of aspiration. These findings indicate a role for sensorimotor interactions in control of swallowing and have implications for the assessment and management of dysphagia after stroke.

Deglutitive laryngeal closure in stroke patients

BACKGROUND

Dysphagia has been reported in up to 70% of patients with stroke, predisposing them to aspiration and pneumonia. Despite this, the mechanism for aspiration remains unclear.

AIMS

To determine the relationship between bolus flow and laryngeal closure during swallowing in patients with stroke and to examine the sensorimotor mechanisms leading to aspiration.

METHODS

Measures of swallowing and bolus flow were taken from digital videofluoroscopic images in 90 patients with stroke and 50 healthy adults, after repeated volitional swallows of controlled volumes of thin liquid. Aspiration was assessed using a validated Penetration-Aspiration Scale. Oral sensation was also measured by electrical stimulation at the faucial pillars.

RESULTS

After stroke, laryngeal ascent was delayed (mean (standard deviation (SD)) 0.31 (0.06) s, p<0.001), resulting in prolongation of pharyngeal transit time (1.17 (0.07) s, p<0.001) without a concomitant increase in laryngeal closure duration (0.84 (0.04) s, p = 0.9). The delay in laryngeal elevation correlated with both the severity of aspiration (r = 0.5, p<0.001) and oral sensation (r = 0.5, p<0.001).

CONCLUSIONS

After stroke, duration of laryngeal delay and degree of sensory deficit are associated with the severity of aspiration. These findings indicate a role for sensorimotor interactions in control of swallowing and have implications for the assessment and management of dysphagia after stroke.

A naturally occurring novel allele of Escherichia coli outer membrane protein A reduces sensitivity to bacteriophage

A novel Escherichia coli outer membrane protein A (OmpA) was discovered through a proteomic investigation of cell surface proteins. DNA polymorphisms were localized to regions encoding the protein's surface-exposed loops which are known phage receptor sites. Bacteriophage sensitivity testing indicated an association between bacteriophage resistance and isolates having the novel ompA allele.

Patterns of Cryptosporidium oocyst shedding by eastern grey kangaroos inhabiting an Australian watershed

The occurrence of Cryptosporidium oocysts in feces from a population of wild eastern grey kangaroos inhabiting a protected watershed in Sydney, Australia, was investigated. Over a 2-year period, Cryptosporidium oocysts were detected in 239 of the 3,557 (6.7%) eastern grey kangaroo fecal samples tested by using a combined immunomagnetic separation and flow cytometric technique. The prevalence of Cryptosporidium in this host population was estimated to range from 0.32% to 28.5%, with peaks occurring during the autumn months. Oocyst shedding intensity ranged from below 20 oocysts/g feces to 2.0 x 10(6) oocysts/g feces, and shedding did not appear to be associated with diarrhea. Although morphologically similar to the human-infective Cryptosporidium hominis and the Cryptosporidium parvum "bovine" genotype oocysts, the oocysts isolated from kangaroo feces were identified as the Cryptosporidium "marsupial" genotype I or "marsupial" genotype II. Kangaroos are the predominant large mammal inhabiting Australian watersheds and are potentially a significant source of Cryptosporidium contamination of drinking water reservoirs. However, this host population was predominantly shedding the marsupial-derived genotypes, which to date have been identified only in marsupial host species.

Phenotypic and genotypic characterization of encapsulated Escherichia coli isolated from blooms in two Australian lakes

Escherichia coli has long been used as an indicator organism for water quality assessment. Recently there has been an accumulation of evidence that suggests some strains of this organism are able to proliferate in the environment, a characteristic that would detract from its utility as an indicator of faecal pollution. Phenotypic and genotypic characterization of E. coli isolated from blooms in two Australian lakes, separated by a distance of approximately 200 km, identified that the blooms were dominated by three E. coli strains. A major phenotypic similarity among the three bloom strains was the presence of a group 1 capsule. Genetic characterization of a conserved region of the cps gene cluster, which encodes group 1 capsules, identified a high degree of genetic variation within the bloom isolates. This differs from previously described encapsulated E. coli strains which are highly conserved at the cps locus. The phenotypic or genotypic profiles of the bloom strains were not identified in 435 E. coli strains isolated from vertebrates. The occurrence of these encapsulated strains suggests that some E. coli have evolved a free-living lifestyle and do not require a host in order to proliferate. The presence of the same three strains in bloom events in different geographical regions of a temperate climate, and at different times, indicates that free-living E. coli strains are able to persist in these water reservoirs. This study provides further evidence of circumstances where caution is required in using E. coli as an indicator organism for water quality.

Genetic characterisation of Cryptosporidium from a wild population of eastern grey kangaroos Macropus giganteus inhabiting a water catchment

Molecular characterisation of Cryptosporidium oocysts isolated from faeces collected from eastern grey kangaroos Macropus giganteus inhabiting an Australian water catchment revealed that this host was susceptible to three types of Cryptosporidium. Nucleotide sequence analysis of the 18S rDNA, Cryptosporidium oocyst wall protein (COWP) and a 70kDa heat shock protein (HSP70) identified an isolate identical to the described Cryptosporidium 'marsupial' genotype. A second isolate had less than 0.5% variation, compared to the described Cryptosporidium 'marsupial' genotype, within the sequences of the 18S rDNA, COWP and HSP70 and 10% variation in the internal transcribed spacer 1 (ITS1). Multilocus analysis of the third Cryptosporidium revealed a novel genotype that had a degree of genetic variation, at the four loci characterised, which was greater than or equivalent to that used to discriminate between currently recognised Cryptosporidium species. These findings have increased our current understanding on the molecular epidemiology of Cryptosporidium in Australian wildlife and have provided information on the types of Cryptosporidium marsupials may shed into the environment.

Evaluation of a combined immunomagnetic separation/flow cytometry technique for epidemiological investigations of Cryptosporidium in domestic and Australian native animals

A combined immunomagnetic separation (IMS) and flow cytometry (FC) technique was developed for the sensitive detection of Cryptosporidium in faecal samples. The IMS/FC technique was found to be approximately 50-fold more sensitive than formol-ether concentration, which is commonly used for Cryptosporidium epidemiological investigations. Of 31 faecal samples from captive animals 16 were found to contain Cryptosporidium oocysts when analysed using the IMS/FC compared to four when using formol-ether concentration (FEC). In a wild population of eastern grey kangaroos Macropus giganteus 66.3% of infected animals were shedding <500oocysts/gfaeces when analysed using IMS/FC. This is below the detection limit for the FEC method. The dispersal of Cryptosporidium in host populations is aggregated, with many individuals shedding low numbers of oocysts and few individuals shedding numbers of oocysts sufficiently high to be detected by FEC. This research demonstrates that the prevalence and oocyst shedding intensity of Cryptosporidium in animal populations will be significantly underestimated using standard detection methods.

Evaluation of tests for anthelmintic resistance in cyathostomes

Resistance, especially to the anthelmintic benzimidazoles (BZ), has been reported in horse cyathostomes world-wide. Diagnosis of resistance has traditionally been made by faecal egg count reduction (FECR) trials, however, this technique has limitations. Some of the shortcomings may be resolved by refining the test or by using an in vitro test. FECR tests and the larval development assay (LDA) were performed on adult horses held on 15 different horse properties across a wide geographical area of NSW, Australia. FECR were measured before and 10-14 after days treatment with oxibendazole (OBZ), morantel (MOR) or ivermectin (IVM) at recommended dose rates. Eight properties were rejected following low pre-treatment egg counts, leaving seven in the study. On these, the majority of larvae recovered from faecal cultures were cyathostomes. Using a definition of resistance as a FECR of <90%, resistance to OBZ was present on six properties and to MOR on two properties. Resistance to IVM was not detected. An alternative method of calculating FECR based on individual horse egg counts pre- and post-treatment was developed and results from the same properties compared with the results of the LDA. For example, for the BZ, correlation coefficients of values of lethal concentration to kill 50% of population (LC50) on LDA and FECR percentages were -0.536 before and -0.704 after OBZ treatment. We conclude that the LDA has the potential to be a single visit test for detection of anthelmintic resistance in horse cyathostomes but requires further investigation and standardisation.

Obstetrician-gynecologists' views on the health risks of obesity

OBJECTIVE

To assess the knowledge and opinions of obstetrician-gynecologists concerning the health risks of obesity and the importance of weight management of patients to clinical practice.

STUDY DESIGN

A questionnaire survey covering physician and patient demography, disease risk related to obesity, relevance of weight management to patient's health, and self-assessments of medical education and training was sent to the 418 American College of Obstetricians and Gynecologists (ACOG) fellows who constitute the Collaborative Ambulatory Research Network and to 700 ACOG fellows selected at random.

RESULTS

Five hundred twenty-five surveys were returned (47.0% response rate). Membership in the network was not a significant factor regarding responses; therefore, the data were pooled. Respondents estimated that 20.6 +/- 0.5% of their patients were obese and that a further 35.9 +/- 0.8% were overweight. The respondents were knowledgeable concerning health risks associated with obesity, and a majority considered obesity to be a major health concern that should be treated. Weight management was considered an important or very important part of practice by 81.5% of respondents. Almost half the respondents (45.5%) thought that the importance of weight management would increase. More than one of three responding physicians (36.4%) had prescribed weight loss medications in the previous year. Most responding physicians did not consider medical school or residency to be sources of information on these issues.

CONCLUSION

Obstetrician-gynecologists think that managing the weight of their patients is part of their clinical responsibilities but do not consider their training in medical school and residency on these topics to be adequate.

Practice trends in outpatient obstetrics and gynecology: findings of the Collaborative Ambulatory Research Network, 1995--2000

Historically, obstetrics and gynecology has been a medical/surgical specialty focusing on women's health and reproductive concerns during the childbearing years. Newer responsibilities-for example, in primary care, gerontology, and genetics-require Ob-Gyns to draw upon a base of medical knowledge that traditionally was not considered germane to their practices. Ob-Gyns are increasingly providing more primary care services to their patients; consequently, the field has expanded considerably. The Collaborative Ambulatory Research Network (CARN) was created in 1990 as a vehicle for investigating issues pertinent to women's health and to the practice of obstetrics and gynecology in the outpatient setting. This article summarizes the findings of CARN studies from 1995 to 2000, covering a range of topics related to women's health across the life cycle, including, but not limited to perinatal care. Topics include nutrition, infectious disease, hormone replacement therapy, psychosocial issues, and genetic testing in obstetric and gynecologic practice. Each study produced a picture of current practice patterns and knowledge of the physicians surveyed. Findings on knowledge, attitudes, and practices varied widely. Overall, Ob-Gyns were knowledgeable and consistent in more traditional areas of practice. Conversely, inconsistencies were observed in newer areas.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completion of this article, the reader will be able to define what the Collaborative Ambulatory Research Network (CARN) involves, describe how CARN obtains its data, and summarize some of the findings of CARN from the years 1995 to 2000.

Relations among measures of body composition, age, and sex in the common marmoset monkey (Callithrix jacchus)

Few studies of body composition have been done in New World primates. In the study reported here, four methods of assessing body composition (body weight, anthropometry, labeled-water dilution, and total body electroconductivity) were compared in 20 marmosets, aged 0.96 to 7.97 years. Males and females did not differ in any measure (P > 0.05). Body weight ranged from 272 to 466 g, and body fat estimates varied from 1.6 to 19.5%. Strong positive correlations were observed between total body water and total body electroconductivity (R2 = 0.77), body weight and fat-free mass (males R2 = 0.95; females R2 = 0.91), and body weight and fat mass (males R2 = 0.86; females R2 = 0.85; P < 0.01). Male and female slopes were equivalent (P > 0.05) for the regressions of fat and fat-free mass against body weight. Positive correlations also were observed between girth measures and fat-free mass (R2 = 0.48 to 0.78) and fat mass (R2 = 0.60 to 0.74; P < 0.01). A good second- order polynomial relationship was observed between age and fat-free mass for the combined sample (R2 = 0.64). Results indicated that: subjects were lean; there was no sexual dimorphism relative to measures; body weight provided a reliable estimate of fat and fat-free mass; and within-subject body weight changes reflected a similar relationship between body weight and fat-free mass as did that across subjects.

Long hours and little sleep: work schedules of residents in obstetrics and gynecology

OBJECTIVE

To investigate residents' work schedules and their attitudes toward limiting their hours.

METHODS

An anonymous survey regarding resident work hours and call schedules was administered to the 4674 obstetric-gynecologic residents who took the year 2000 Council on Resident Education in Obstetrics and Gynecology in-training examination.

RESULTS

A total of 4510 surveys were analyzed (96.5%). Three of four (75.5%) respondents reported working between 61 and 100 hours each week. Most (71.3%) reported sleeping less than 3 hours while on night call. Eight of ten reported having postcall clinical responsibilities. The reported number of hours on call declined and the reported number of hours of sleep increased with year of residency. Three of four residents wanted limits on their work hours. Residents who reported longer on-call hours or less sleep during night shift were significantly more likely to want a restriction on work hours. Fatigue was the most commonly selected reason (77.6%) followed by "need more personal time" (76.3%), and "fear of compromising quality of care" (59.8%). Women were more concerned about fatigue than were men. Among residents who did not want work hour restrictions, "additional surgical experience" was the most commonly selected reason (69.0%).

CONCLUSION

Residents in obstetrics and gynecology report working long hours, and experiencing periods of little sleep. Most want their work hours to be limited. Fatigue is a major concern among residents that want their hours limited. A sizable minority worries that such limits might also limit their experience.

Effects of perceptions and mentorship on pursuing a career in academic medicine in obstetrics and gynecology

PURPOSE

To understand the perceptions of residents and Fellows in obstetrics and gynecology about the impacts of race or ethnicity, gender, and mentorship experiences on pursuing careers in academic medicine.

METHOD

Two surveys were administered: one to a sample of 2,000 Fellows of the American College of Obstetricians and Gynecologists, and one to the 4,814 obstetrics and gynecology residents taking the 1998 in-training examination. The questionnaires asked about demographics, perceptions about careers in academic medicine, and residents' experiences with mentorship.

RESULTS

Response rates were 96.8% for residents and 40.6% for FELLOWS: Of the residents, 26.1% indicated they would not consider a career in academic medicine. First-year women residents were more inclined to pursue careers in academic medicine than were first-year men (p =.042), but their interest declined during residency. Women residents (43%)-especially minorities-felt that men were mentored and recruited more for faculty positions, while men (38%) felt that women were mentored and recruited more. Fellows' reports of recruitment did not differ by gender. Most white residents did not perceive racial or ethnic bias in mentoring or recruiting, while most non-white residents did. Almost one third of non-white women residents felt that supervisors were more likely to condescend to women and minority individuals.

CONCLUSIONS

It is likely that neither men nor women residents in obstetrics and gynecology receive adequate mentorship for careers in academic medicine. Perceptions of bias are a serious barrier to developing racial, ethnic, and gender diversity in leadership positions.

Ingestion of calcium solutions by common marmosets (Callithrix jacchus)

Callithrix jacchus, the common marmoset, is a small New World primate that feeds on insects, fruit, and gum, and has a high reproductive rate for a primate. Insects are generally a poor source of dietary calcium, while gums may contain significant levels of calcium. Their high reproductive rate also suggests that reproductive female C. jacchus might be susceptible to calcium deficiency. Thus, we hypothesized that common marmosets might find solutions containing calcium to be palatable. We used choice experiments to examine this phenomenon in 14 male and 19 female common marmosets. Animals were presented with identical water bottles containing either deionized water or a calcium lactate solution (either 2% or 4% calcium lactate by weight) and intake was measured. Serum 25-OH-vitamin D was monitored in a subset of the animals in the experiment to examine the role of vitamin D in this behavior. Our results demonstrated that C. jacchus can distinguish between plain water and a calcium lactate solution, and that in general they prefer calcium solutions. Although animals with marginal vitamin D status did have strong preferences for calcium solutions, they did not ingest significantly more of the calcium solutions than animals that were vitamin D-replete. Nulliparous females and males did not differ in the amounts of calcium solutions ingested. Lactating females ingested the greatest volume of the calcium solutions.

Knowledge and clinical practice regarding folic acid among obstetrician-gynecologists

OBJECTIVE

To assess obstetrician-gynecologists' knowledge of and clinical practice concerning folate.

METHODS

We mailed surveys on nutrition during pregnancy to the 230 ACOG Fellows who are members of the Collaborative Ambulatory Research Network and to a random sample of 800 Fellows who are not members of the Network. Our results focus on questions concerning folate.

RESULTS

We analyzed 488 surveys (a 47.4% response rate). Approximately two thirds of respondents screen their pregnant patients for folate intake. Fewer (53%) screen their nonpregnant patients of childbearing age. Those who screened their patients for folate intake were more likely to counsel pregnant patients about diet. They also were more likely to believe that nutritional counseling would improve pregnancy outcomes (70.0% versus 56.5%) and overall patient health (77.5% versus 66.5%). Most Fellows were aware that macrocytic anemia was a manifestation of folate deficiency (90.4%) and that folic acid supplementation during preconception and the early prenatal period helps protect against neural tube defects (96.5%). They were aware that alcoholics (91.4%), smokers (61.3%), and lactating women (53.5%) are at increased risk of folate deficiency. They were less aware of other consequences of low folate intake, such as increased serum homocysteine (20.3%). Respondents who screen their pregnant patients for folate intake correctly answered more of the knowledge questions about folate than physicians who do not screen.

CONCLUSION

Obstetrician-gynecologists are generally aware of the link between folate intake and neural tube defects, but are less aware of other aspects of folate metabolism.

Gynecologists' training, knowledge, and experiences in genetics: a survey

OBJECTIVE

To explore gynecologists' knowledge, training, and practice experience with genetic screening and DNA-based testing.

METHODS

A questionnaire survey was sent to 1,248 ACOG Fellows, of whom 564 (45%) responded. One hundred thirty-four respondents (24%) reported that they do not order DNA-based tests or take family histories to screen for heritable diseases or disorders. Results from the 428 respondents who provide genetic screening services are reported.

RESULTS

Most physicians (90%) knew that genetic tests are most informative when used in conjunction with family histories. Gynecologists gave more correct responses regarding genetic testing for breast and ovarian cancers than for colon cancer and other adult-onset diseases. Sixty-five percent of the respondents had not received formal training in DNA-based testing in gynecologic practice. Older physicians were less likely to have had training. Younger physicians generally gave more correct responses on the knowledge portion of the survey (r = -.165, P < .01). Physicians who had formal training in genetics gave more correct answers. Physicians who order DNA-based tests scored higher than those who do not and had no formal training, but not higher than those who had formal training and do not order DNA-based tests.

CONCLUSION

Gynecologists were more knowledgeable about genetic issues pertaining to breast and ovarian cancer than to other cancers or certain adult-onset disorders. Training appeared to increase knowledge. Increased training and affiliation with genetic specialists and others could improve gynecologists' ability to use genetic screening in clinical practice.

The role of calcium in health and disease

Skeletal fragility at the end of the life span (osteoporosis) is a major source of morbidity and mortality. Adequate calcium intake from childhood to the end of the life span is critical for the formation and retention of a healthy skeleton. High intakes of calcium and vitamin D potentiate the bone loss prevention effects of hormone replacement therapy in postmenopausal women. Pregnancy and lactation are not risk factors for skeletal fragility, although lactation is associated with a transient loss of bone that cannot be prevented by calcium supplementation. Low calcium intake has been implicated in the development of hypertension, colon cancer, and premenstrual syndrome, and it is associated with low intakes of many other nutrients. Encouragement of increased consumption of calcium-rich foods has the potential to be a cost-effective strategy for reducing fracture incidence later in life and for increasing patients' dietary quality and overall health.

Knowledge and clinical practice regarding calcium nutrition among obstetrician-gynecologists

OBJECTIVE

To survey the knowledge of and attitude toward nutrition among practicing obstetrician-gynecologists, using calcium as a specific example.

METHODS

Our survey on calcium nutrition consisted of 29 questions divided into four categories: demographic information, professional interest and clinical practice, knowledge and opinions, and education. We mailed this survey to the 244 ACOG Fellows who are members of the Collaborative Ambulatory Research Network and to a random sample of 756 Fellows who are not members of the Collaborative Ambulatory Research Network.

RESULTS

Most (75.4%) respondents considered making dietary recommendations an important part of their practice. Interest in nutrition was correlated significantly with its perceived importance in clinical practice and was associated with a greater self-reported likelihood of making dietary recommendations to patients and referring patients to nutritional counseling. Nutrition was of greater importance to women and to older respondents. Women were more likely to make dietary recommendations to patients. Men were more likely to recommend nonfoods and higher fat foods as sources of dietary calcium. The daily calcium intake that obstetrician-gynecologists recommended for different types of patients varied widely but did not differ between male and female respondents. The responses to the knowledge questions concerning calcium metabolism were predominantly "don't know."

CONCLUSIONS

Although specific knowledge of calcium metabolism and regulation was incomplete, obstetrician-gynecologists generally recognized the importance of nutrition in their clinical practice. Being older and female independently increased the perceived importance of nutrition.