8 results on '"Greenhill, AR"'
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2. Salmonella enterica Serovar Hvittingfoss in Bar-Tailed Godwits (Limosa lapponica) from Roebuck Bay, Northwestern Australia.
- Author
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Smith HG, Bean DC, Hawkey J, Clarke RH, Loyn R, Larkins JA, Hassell C, Valcanis M, Pitchers W, and Greenhill AR
- Subjects
- Animals, Bird Diseases microbiology, Female, Incidence, Male, Prevalence, Salmonella Infections, Animal microbiology, Serogroup, Western Australia epidemiology, Bird Diseases epidemiology, Charadriiformes, Salmonella Infections, Animal epidemiology, Salmonella enterica isolation & purification
- Abstract
Salmonella enterica serovar Hvittingfoss is an important foodborne serotype of Salmonella , being detected in many countries where surveillance is conducted. Outbreaks can occur, and there was a recent multistate foodborne outbreak in Australia. S Hvittingfoss can be found in animal populations, though a definitive animal host has not been established. Six species of birds were sampled at Roebuck Bay, a designated Ramsar site in northwestern Australia, resulting in 326 cloacal swabs for bacterial culture. Among a single flock of 63 bar-tailed godwits ( Limosa lapponica menzbieri ) caught at Wader Spit, Roebuck Bay, in 2018, 17 (27%) were culture positive for Salmonella All other birds were negative for Salmonella The isolates were identified as Salmonella enterica serovar Hvittingfoss. Phylogenetic analysis revealed a close relationship between isolates collected from godwits and the S Hvittingfoss strain responsible for a 2016 multistate foodborne outbreak originating from tainted cantaloupes (rock melons) in Australia. While it is not possible to determine how this strain of S Hvittingfoss was introduced into the bar-tailed godwits, these findings show that wild Australian birds are capable of carrying Salmonella strains of public health importance. IMPORTANCE Salmonella is a zoonotic pathogen that causes gastroenteritis and other disease presentations in both humans and animals. Serovars of S. enterica commonly cause foodborne disease in Australia and globally. In 2016-2017, S Hvittingfoss was responsible for an outbreak that resulted in 110 clinically confirmed human cases throughout Australia. The origin of the contamination that led to the outbreak was never definitively established. Here, we identify a migratory shorebird, the bar-tailed godwit, as an animal reservoir of S Hvittingfoss. These birds were sampled in northwestern Australia during their nonbreeding period. The presence of a genetically similar S Hvittingfoss strain circulating in a wild bird population, 2 years after the 2016-2017 outbreak and ∼1,500 km from the suspected source of the outbreak, demonstrates a potentially unidentified environmental reservoir of S Hvittingfoss. While the birds cannot be implicated in the outbreak that occurred 2 years prior, this study does demonstrate the potential role for wild birds in the transmission of this important foodborne pathogen., (Copyright © 2020 American Society for Microbiology.)
- Published
- 2020
- Full Text
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3. Impact of intermittent preventive treatment in pregnancy with azithromycin-containing regimens on maternal nasopharyngeal carriage and antibiotic sensitivity of Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus: a cross-sectional survey at delivery.
- Author
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Unger HW, Aho C, Ome-Kaius M, Wangnapi RA, Umbers AJ, Jack W, Lafana A, Michael A, Hanieh S, Siba P, Mueller I, Greenhill AR, and Rogerson SJ
- Subjects
- Adolescent, Adult, Antibiotic Prophylaxis adverse effects, Antimalarials adverse effects, Azithromycin adverse effects, Bacterial Infections epidemiology, Carrier State epidemiology, Carrier State microbiology, Cross-Sectional Studies, Drug Combinations, Drug Resistance, Bacterial, Female, Haemophilus influenzae drug effects, Haemophilus influenzae isolation & purification, Humans, Microbial Sensitivity Tests, Papua New Guinea, Pregnancy, Pyrimethamine adverse effects, Pyrimethamine therapeutic use, Serotyping, Staphylococcus aureus drug effects, Staphylococcus aureus isolation & purification, Streptococcus pneumoniae drug effects, Streptococcus pneumoniae isolation & purification, Sulfadoxine adverse effects, Sulfadoxine therapeutic use, Young Adult, Antibiotic Prophylaxis methods, Antimalarials therapeutic use, Azithromycin therapeutic use, Bacterial Infections microbiology, Malaria prevention & control, Nasopharynx microbiology
- Abstract
Sulfadoxine-pyrimethamine (SP) plus azithromycin (AZ) (SPAZ) has the potential for intermittent preventive treatment of malaria in pregnancy (IPTp), but its use could increase circulation of antibiotic-resistant bacteria associated with severe pediatric infections. We evaluated the effect of monthly SPAZ-IPTp compared to a single course of SP plus chloroquine (SPCQ) on maternal nasopharyngeal carriage and antibiotic susceptibility of Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus at delivery among 854 women participating in a randomized controlled trial in Papua New Guinea. Serotyping was performed, and antibiotic susceptibility was evaluated by disk diffusion and Etest. Potential risk factors for carriage were examined. Nasopharyngeal carriage at delivery of S. pneumoniae (SPAZ, 7.2% [30/418], versus SPCQ, 19.3% [84/436]; P<0.001) and H. influenzae (2.9% [12/418] versus 6.0% [26/436], P=0.028), but not S. aureus, was significantly reduced among women who had received SPAZ-IPTp. The number of macrolide-resistant pneumococcal isolates was small but increased in the SPAZ group (13.3% [4/30], versus SPCQ, 2.2% [2/91]; P=0.033). The proportions of isolates with serotypes covered by the 13-valent pneumococcal conjugate vaccine were similar (SPAZ, 10.3% [3/29], versus SPCQ, 17.6% [16/91]; P=0.352). Although macrolide-resistant isolates were rare, they were more commonly detected in women who had received SPAZ-IPTp, despite the significant reduction of maternal carriage of S. pneumoniae and H. influenzae observed in this group. Future studies on SPAZ-IPTp should evaluate carriage and persistence of macrolide-resistant S. pneumoniae and other pathogenic bacteria in both mothers and infants and assess the clinical significance of their circulation., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)
- Published
- 2015
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4. Evaluation of serological diagnostic tests for typhoid fever in Papua New Guinea using a composite reference standard.
- Author
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Siba V, Horwood PF, Vanuga K, Wapling J, Sehuko R, Siba PM, and Greenhill AR
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Costs and Cost Analysis, Diagnostic Tests, Routine economics, Diagnostic Tests, Routine standards, Female, Fever diagnosis, Fever etiology, Humans, Infant, Male, Middle Aged, Papua New Guinea, Sensitivity and Specificity, Serologic Tests economics, Serologic Tests methods, Serologic Tests standards, Typhoid Fever pathology, Young Adult, Diagnostic Tests, Routine methods, Reference Standards, Typhoid Fever diagnosis
- Abstract
Typhoid fever remains a major global health problem. A major impediment to improving outcomes is the lack of appropriate diagnostic tools, which have not significantly improved in low-income settings for 100 years. We evaluated two commercially available rapid diagnostic tests (Tubex and TyphiDot), a prototype (TyphiRapid TR-02), and the commonly used single-serum Widal test in a previously reported high-burden area of Papua New Guinea. Samples were collected from 530 outpatients with axillary temperatures of ≥37.5°C, and analysis was conducted on all malaria-negative samples (n = 500). A composite reference standard of blood culture and PCR was used, by which 47 participants (9.4%) were considered typhoid fever positive. The sensitivity and specificity of the Tubex (51.1% and 88.3%, respectively) and TyphiDot (70.0% and 80.1%, respectively) tests were not high enough to warrant their ongoing use in this setting; however, the sensitivity and specificity for the TR-02 prototype were promising (89.4% and 85.0%, respectively). An axillary temperature of ≥38.5°C correlated with typhoid fever (P = 0.014). With an appropriate diagnostic test, conducting typhoid fever diagnosis only on patients with high-grade fever could dramatically decrease the costs associated with diagnosis while having no detrimental impact on the ability to accurately diagnose the illness.
- Published
- 2012
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5. Multilocus sequence typing of Streptococcus pneumoniae by use of mass spectrometry.
- Author
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Dunne EM, Ong EK, Moser RJ, Siba PM, Phuanukoonnon S, Greenhill AR, Robins-Browne RM, Mulholland EK, and Satzke C
- Subjects
- Alleles, Automation methods, Child, Preschool, Humans, Infant, Streptococcus pneumoniae chemistry, Streptococcus pneumoniae genetics, Multilocus Sequence Typing methods, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods, Streptococcus pneumoniae classification
- Abstract
Multilocus sequence typing (MLST) is an important tool for the global surveillance of bacterial pathogens that is performed by comparing the sequences of designated housekeeping genes. We developed and tested a novel mass spectrometry-based method for MLST of Streptococcus pneumoniae. PCR amplicons were subjected to in vitro transcription and base-specific cleavage, followed by analysis of the resultant fragments by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Comparison of the cleavage fragment peak patterns to a reference sequence set permitted automated identification of alleles. Validation experiments using 29 isolates of S. pneumoniae revealed that the results of MALDI-TOF MS MLST matched those obtained by traditional sequence-based MLST for 99% of alleles and that the MALDI-TOF MS method accurately identified two single-nucleotide variations. The MADLI-TOF MS method was then used for MLST analysis of 43 S. pneumoniae isolates from Papua New Guinean children. The majority of the isolates present in this population were not clonal and contained seven new alleles and 30 previously unreported sequence types.
- Published
- 2011
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6. Groundwater seeps facilitate exposure to Burkholderia pseudomallei.
- Author
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Baker A, Tahani D, Gardiner C, Bristow KL, Greenhill AR, and Warner J
- Subjects
- Australia epidemiology, Bacterial Proteins genetics, Burkholderia pseudomallei classification, Burkholderia pseudomallei genetics, Cluster Analysis, DNA, Bacterial genetics, Humans, Melioidosis microbiology, Membrane Transport Proteins genetics, Multilocus Sequence Typing, Real-Time Polymerase Chain Reaction, Burkholderia pseudomallei isolation & purification, Environmental Exposure, Groundwater microbiology, Melioidosis epidemiology, Soil Microbiology
- Abstract
Burkholderia pseudomallei is a saprophytic bacterium which is the causative agent of melioidosis, a common cause of fatal bacterial pneumonia and sepsis in the tropics. The incidence of melioidosis is clustered spatially and temporally and is heavily linked to rainfall and extreme weather events. Clinical case clustering has recently been reported in Townsville, Australia, and has implicated Castle Hill, a granite monolith in the city center, as a potential reservoir of infection. Topsoil and water from seasonal groundwater seeps were collected around the base of Castle Hill and analyzed by quantitative real-time PCR targeting the type III secretion system genes for the presence of B. pseudomallei. The organism was identified in 65% (95% confidence interval [CI], 49.5 to 80.4) of soil samples (n = 40) and 92.5% (95% CI, 83.9 to 100) of seasonal groundwater samples (n = 40). Further sampling of water collected from roads and gutters in nearby residential areas after an intense rainfall event found that 88.2% (95% CI, 72.9 to 100) of samples (n = 16) contained viable B. pseudomallei at concentrations up to 113 CFU/ml. Comparison of isolates using multilocus sequence typing demonstrated clinical matches and close associations between environmental isolates and isolates derived from clinical samples from patients in Townsville. This study demonstrated that waterborne B. pseudomallei from groundwater seeps around Castle Hill may facilitate exposure to B. pseudomallei and contribute to the clinical clustering at this site. Access to this type of information will advise the development and implementation of public health measures to reduce the incidence of melioidosis.
- Published
- 2011
- Full Text
- View/download PDF
7. Increasing chloramphenicol resistance in Streptococcus pneumoniae isolates from Papua New Guinean children with acute bacterial meningitis.
- Author
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Manning L, Laman M, Greenhill AR, Michael A, Siba P, Mueller I, and Davis TM
- Subjects
- Chloramphenicol therapeutic use, Drug Resistance, Bacterial, Humans, Meningitis, Bacterial drug therapy, Microbial Sensitivity Tests, Papua New Guinea, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Chloramphenicol pharmacology, Meningitis, Bacterial microbiology, Streptococcus pneumoniae drug effects
- Abstract
In Papua New Guinean (PNG) children with acute bacterial meningitis (ABM), all Haemophilus influenzae isolates were resistant to chloramphenicol. Although Streptococcus pneumoniae isolates had a median chloramphenicol MIC of 3 μg/ml, it was ≥4 μg/ml in 42.8%, and the likelihood of an area under the 24-hour concentration-time curve/MIC ratio of >100 h at a MIC of ≥4 μg/ml was approximately 50%. All isolates were ceftriaxone sensitive. These data support ceftriaxone rather than conventional chloramphenicol for all PNG children with suspected ABM.
- Published
- 2011
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8. Physicochemical parameters for growth of the sea ice bacteria Glaciecola punicea ACAM 611(T) and Gelidibacter sp. strain IC158.
- Author
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Nichols DS, Greenhill AR, Shadbolt CT, Ross T, and McMeekin TA
- Subjects
- Antarctic Regions, Hydrogen-Ion Concentration, Ice, Seawater microbiology, Sodium Chloride, Temperature, Bacteria growth & development, Bacteroidetes growth & development
- Abstract
The water activity and pH ranges for growth of Glaciecola punicea (a psychrophile) were extended when this organism was grown at suboptimal rather than optimal temperatures. No such extension was observed for Gelidibacter sp. strain IC158 (a psychrotolerant bacterium) at analogous temperatures. Salinity and pH may be primary physicochemical parameters controlling bacterial community development in sea ice.
- Published
- 1999
- Full Text
- View/download PDF
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