RESUMO
SUMMARY: The reliable and timely recognition of outbreaks is a key component of public health surveillance for foodborne diseases. Whole genome sequencing (WGS) offers high resolution typing of foodborne bacterial pathogens and facilitates the accurate detection of outbreaks. This detection relies on grouping WGS data into clusters at an appropriate genetic threshold. However, methods and tools for selecting and adjusting such thresholds according to the required resolution of surveillance and epidemiological context are lacking. Here we present DODGE (Dynamic Outbreak Detection for Genomic Epidemiology), an algorithm to dynamically select and compare these genetic thresholds. DODGE can analyse expanding datasets over time and clusters that are predicted to correspond to outbreaks (or "investigation clusters") can be named with established genomic nomenclature systems to facilitate integrated analysis across jurisdictions. DODGE was tested in two real-world Salmonella genomic surveillance datasets of different duration, 2 months from Australia and 9 years from the United Kingdom. In both cases only a minority of isolates were identified as investigation clusters. Two known outbreaks in the United Kingdom dataset were detected by DODGE and were recognized at an earlier timepoint than the outbreaks were reported. These findings demonstrated the potential of the DODGE approach to improve the effectiveness and timeliness of genomic surveillance for foodborne diseases and the effectiveness of the algorithm developed. AVAILABILITY AND IMPLEMENTATION: DODGE is freely available at https://github.com/LanLab/dodge and can easily be installed using Conda.
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Algoritmos , Surtos de Doenças , Doenças Transmitidas por Alimentos , Genoma Bacteriano , Humanos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/epidemiologia , Sequenciamento Completo do Genoma/métodos , Genômica/métodos , Austrália , Reino Unido , Salmonella/genéticaRESUMO
In Queensland, Australia, 31 of 96 Shiga toxinâproducing Escherichia coli cases during 2020-2022 were reported by a specialty pathology laboratory servicing alternative health practitioners. Those new cases were more likely to be asymptomatic or paucisymptomatic, prompting a review of the standard public health response.
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Infecções por Escherichia coli , Síndrome Hemolítico-Urêmica , Escherichia coli Shiga Toxigênica , Humanos , Escherichia coli Shiga Toxigênica/genética , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/epidemiologia , Queensland/epidemiologia , Diarreia/diagnóstico , Síndrome Hemolítico-Urêmica/diagnóstico , Austrália/epidemiologiaRESUMO
Melioidosis, caused by the environmental gram-negative bacterium Burkholderia pseudomallei, usually develops in adults with predisposing conditions and in Australia more commonly occurs during the monsoonal wet season. We report an outbreak of 7 cases of melioidosis in immunocompetent children in Australia. All the children had participated in a single-day sporting event during the dry season in a tropical region of Australia, and all had limited cutaneous disease. All case-patients had an adverse reaction to oral trimethoprim/sulfamethoxazole treatment, necessitating its discontinuation. We describe the clinical features, environmental sampling, genomic epidemiologic investigation, and public health response to the outbreak. Management of this outbreak shows the potential benefits of making melioidosis a notifiable disease. The approach used could also be used as a framework for similar outbreaks in the future.
Assuntos
Burkholderia pseudomallei , Melioidose , Adulto , Humanos , Criança , Melioidose/diagnóstico , Melioidose/tratamento farmacológico , Melioidose/epidemiologia , Burkholderia pseudomallei/genética , Austrália/epidemiologia , Genômica , Surtos de DoençasRESUMO
Toxigenic diphtheria is rare in Australia with generally fewer than 10 cases reported annually; however, since 2020, there has been an increase in toxin gene-bearing isolates of Corynebacterium diphtheriae cases in North Queensland, with an approximately 300% escalation in cases in 2022. Genomic analysis on both toxin gene-bearing and non-toxin gene-bearing C. diphtheriae isolated from this region between 2017 and 2022 demonstrated that the surge in cases was largely due to one sequence type (ST), ST381, all of which carried the toxin gene. ST381 isolates collected between 2020 and 2022 were highly genetically related to each other, and less closely related to ST381 isolates collected prior to 2020. The most common ST in non-toxin gene-bearing isolates from North Queensland was ST39, an ST that has also been increasing in numbers since 2018. Phylogenetic analysis demonstrated that ST381 isolates were not closely related to any of the non-toxin gene-bearing isolates collected from this region, suggesting that the increase in toxigenic C. diphtheriae is likely due to the expansion of a toxin gene-bearing clone that has moved into the region rather than an already endemic non-toxigenic strain acquiring the toxin gene.
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Corynebacterium diphtheriae , Difteria , Surtos de Doenças , Humanos , Austrália/epidemiologia , Corynebacterium diphtheriae/genética , Difteria/epidemiologia , Toxina Diftérica/genética , Genômica , Filogenia , Queensland , Epidemiologia Molecular , Saúde PúblicaRESUMO
We report a multistate Salmonella enterica serovar Heidelberg outbreak in Australia during 2018-2019. Laboratory investigation of cases reported across 5 jurisdictions over a 7-month period could not identify a source of infection but detected indicators of severity and invasiveness. The hospitalization rate of 36% suggested a moderately severe clinical picture.
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Intoxicação Alimentar por Salmonella , Salmonella enterica , Austrália/epidemiologia , Surtos de Doenças , Humanos , Intoxicação Alimentar por Salmonella/epidemiologia , SorogrupoRESUMO
BACKGROUND: The purpose of this study was to investigate the use of routinely available rectal swabs as a surrogate sample type for testing the gut microbiome and monitoring antibiotic effects on key gut microorganisms, of patients hospitalised in an intensive care unit. A metagenomic whole genome sequencing approach was undertaken to determine the diversity of organisms as well as resistance genes and to compare findings between the two sampling techniques. RESULTS: No significant difference was observed in overall diversity between the faeces and rectal swabs and sampling technique was not demonstrated to predict microbial community variation. More human DNA was present in the swabs and some differences were observed only for a select few anaerobes and bacteria also associated with skin and/or the female genitourinary system, possibly reflecting sampling site or technique. Antibiotics and collections at different times of admission were both considered significant influences on microbial community composition alteration. Detection of antibiotic resistance genes between rectal swabs and faeces were overall not significantly different, although some variations were detected with a potential association with the number of human sequence reads in a sample. CONCLUSION: Testing the gut microbiome using standard rectal swab collection techniques currently used for multi-resistant organism screening has been demonstrated to have utility in gut microbiome monitoring in intensive care. The use of information from this article, in terms of methodology as well as near equivalence demonstrated between rectal swabs and faeces will be able to support and potentially facilitate the introduction into clinical practice.
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Microbioma Gastrointestinal , Microbiota , Antibacterianos , Cuidados Críticos , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Humanos , Microbiota/genética , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: Hemotropic mycoplasmas (hemoplasmas) infect animals and humans and can lead to clinical syndromes mainly characterized by hemolytic anemia. A novel pathogen, Candidatus Mycoplasma haemohominis, was recently associated with a case of human hemoplasmosis in Europe. Here we report the first detection of this pathogen in an Australian patient exhibiting persistent fever, hemolytic anemia, and pancytopenia over a 10-month period. METHODS: After exhaustive negative testing for human infectious diseases, whole genome sequencing (WGS) was performed on the patient's bone marrow aspirate, using an Illumina NextSeq500 platform. Conventional polymerase chain reaction (PCR), followed by Sanger sequencing, was then performed on blood samples using novel Mycoplasma-specific primers targeting the 16S ribosomal RNA gene. In addition, a Mycoplasma-specific fluorescence in situ hybridization (FISH) assay was developed to differentiate Mycoplasma cells from other erythrocyte inclusions (eg, Pappenheimer and Howell-Jolly bodies) which are morphologically similar to bacterial cocci by light microscopy. RESULTS: WGS analysis revealed that approximately 0.04% of the total number of unmapped reads to human genome corresponded to Mycoplasma species. A 1-kb Mycoplasma 16S fragment was successfully amplified by conventional PCR, and sequence analyses revealed 100% identity with Candidatus Mycoplasma haemohominis. FISH confirmed that several (approximately 2%) epierythrocytic inclusions initially observed by light microscopy corresponded to Mycoplasma cells. CONCLUSIONS: This represents the second report of hemolytic anemia associated with hemoplasma infection in a human, and the first report of human hemoplasmosis in Australia. This study highlights the importance of new and emerging diagnostic approaches and need for further investigations on the epidemiology of Candidatus Mycoplasma haemohominis in Australia.
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Infecções por Mycoplasma , Mycoplasma , Animais , Austrália , Cuidadores , DNA Bacteriano/genética , Europa (Continente) , Humanos , Hibridização in Situ Fluorescente , Mycoplasma/genética , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/veterinária , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: Acquisition of IncI1 plasmids by members of the Enterobacteriaceae sometimes leads to transfer of antimicrobial resistance and colicinogeny as well as change of phage type in Salmonella Typhimurium. Isolates of S. Typhimurium from a 2015 outbreak of food poisoning were found to contain an IncI1 plasmid implicated in change of phage type from PT135a to U307 not previously reported. The origin of the changes of phage type associated with this IncI1 plasmid was investigated. In addition, a comparison of its gene composition with that of IncI1 plasmids found in local isolates of S. Typhimurium typed as U307 from other times was undertaken. This comparison was extended to IncI1 plasmids in isolates of phage types PT6 and PT6 var. 1 which are thought to be associated with acquisition of IncI1 plasmids. RESULTS: Analysis of IncI1 plasmids from whole genome sequencing of isolates implicated a gene coding for a 1273 amino acid protein present only in U307 isolates as the likely source of change of phage type. The IncI1 plasmids from PT6 and PT6 var. 1 isolates all had the ibfA gene present in IncI1 plasmid R64. This gene inhibits growth of bacteriophage BF23 and was therefore the possible source of change of phage type. A fuller comparison of the genetic composition of IncI1 plasmids from U307 isolates and PT6 and PT6 var. 1 isolates along with two IncI1 plasmids from S. Typhimurium isolates not showing change of phage type was undertaken. Plasmids were classified as either 'Delta' or 'Col' IncI1 plasmids according to whether genes between repZ and the rfsF site showed high identity to genes in the same location in R64 or ColIb-P9 plasmids respectively. Comparison of the tra gene sets and the pil gene sets across the range of sequenced plasmids identified Delta and Col plasmids with almost identical sequences for both sets of genes. This indicated a genetic recombination event leading to a switch between Delta and Col gene sets at the rfsF site. Comparisons of other gene sets showing significant variation among the sequenced plasmids are reported. Searches of the NCBI GenBank database using DNA and protein sequences of interest from the sequenced plasmids identified global IncI1 plasmids with extensive regions showing 99 to 100% identity to some of the plasmids sequenced in this study indicating evidence for widespread distribution of these plasmids. CONCLUSION: Two genes possibly associated with change of phage type were identified in IncI1 plasmids. IncI1 plasmids were classified as either 'Delta' or 'Col' plasmids and other sequences of significant variation among these plasmids were identified. This study offers a new perspective on the understanding of the gene composition of IncI1 plasmids. The sequences of newly sequenced IncI1 plasmids could be compared against the regions of significant sequence variation identified in this study to understand better their overall gene composition and relatedness to other IncI1 plasmids in the databases.
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Plasmídeos/genética , Salmonella typhimurium/genética , Salmonella typhimurium/virologia , Tipagem MolecularRESUMO
Epidemiological surveillance of Shigella spp. in Australia is conducted to inform public health response. Multi-drug resistance has recently emerged as a contributing factor to sustained local transmission of Shigella spp. All data were collected as part of routine public health surveillance, and strains were whole-genome sequenced for further molecular characterisation. 108 patients with an endemic regional Shigella flexneri strain were identified between 2016 and 2019. The S. flexneri phylogroup 3 strain endemic to northern Australia acquired a multi-drug resistance conferring blaDHA plasmid, which has an IncFII plasmid backbone with virulence and resistance elements typically found in IncR plasmids. This is the first report of multi-drug resistance in Shigella sp. in Australia that is not associated with men who have sex with men. This strain caused an outbreak of multi-drug-resistant S. flexneri in northern Australia that disproportionality affects Aboriginal and Torres Strait Islander children. Community controlled public health action is recommended.
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Surtos de Doenças , Farmacorresistência Bacteriana Múltipla/genética , Disenteria Bacilar , Doenças Endêmicas , Shigella flexneri , Adolescente , Austrália/epidemiologia , Disenteria Bacilar/epidemiologia , Disenteria Bacilar/microbiologia , Humanos , Plasmídeos , Shigella flexneri/genética , Shigella flexneri/isolamento & purificaçãoRESUMO
BACKGROUND: Rapid diagnosis and appropriate treatment is imperative in bacterial sepsis due increasing risk of mortality with every hour without appropriate antibiotic therapy. Atypical infections with fastidious organisms may take more than 4 days to diagnose leading to calls for improved methods for rapidly diagnosing sepsis. Capnocytophaga canimorsus is a slow-growing, fastidious gram-negative bacillus which is a common commensal within the mouths of dogs, but rarely cause infections in humans. C. canimorsus sepsis risk factors include immunosuppression, alcoholism and elderly age. Here we report on the application of emerging nanopore sequencing methods to rapidly diagnose an atypical case of C. canimorsus septic shock. CASE PRESENTATION: A 62 year-old female patient was admitted to an intensive care unit with septic shock and multi-organ failure six days after a reported dog bite. Blood cultures were unable to detect a pathogen after 3 days despite observed intracellular bacilli on blood smears. Real-time nanopore sequencing was subsequently employed on whole blood to detect Capnocytophaga canimorsus in 19 h. The patient was not immunocompromised and did not have any other known risk factors. Whole-genome sequencing of clinical sample and of the offending dog's oral swabs showed near-identical C. canimorsus genomes. The patient responded to antibiotic treatment and was discharged from hospital 31 days after admission. CONCLUSIONS: Use of real-time nanopore sequencing reduced the time-to-diagnosis of Capnocytophaga canimorsus in this case from 6.25 days to 19 h. Capnocytophaga canimorsus should be considered in cases of suspected sepsis involving cat or dog contact, irrespective of the patient's known risk factors.
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Mordeduras e Picadas/complicações , Capnocytophaga/isolamento & purificação , Choque Séptico/diagnóstico , Animais , Antibacterianos/uso terapêutico , Capnocytophaga/efeitos dos fármacos , Capnocytophaga/genética , Gatos , Cães , Feminino , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Hospedeiro Imunocomprometido , Pessoa de Meia-Idade , Nanoporos , Análise de Sequência de DNA , Choque Séptico/imunologia , Choque Séptico/microbiologiaRESUMO
Between February and April 2018, three ceftriaxone-resistant and high-level azithromycin-resistant Neisseria gonorrhoeae cases were identified; one in the United Kingdom and two in Australia. Whole genome sequencing was used to show that the isolates from these cases belong to a single gonococcal clone, which we name the A2543 clone.
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Azitromicina/uso terapêutico , Ceftriaxona/uso terapêutico , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/isolamento & purificação , Adulto , Antibacterianos/uso terapêutico , Austrália , Azitromicina/farmacologia , Ceftriaxona/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Genótipo , Gonorreia/tratamento farmacológico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae/efeitos dos fármacos , Filogenia , Polimorfismo de Nucleotídeo Único , Vigilância de Evento Sentinela , Reino Unido , Sequenciamento Completo do GenomaRESUMO
After conventional molecular and serologic testing failed to diagnose the cause of illness, deep sequencing identified spotted fever group Rickettsia DNA in a patient's blood sample. Sequences belonged to R. honei, the causative agent of Flinders Island spotted fever. Next-generation sequencing is proving to be a useful tool for clinical diagnostics.
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Rickettsia/isolamento & purificação , Rickettsiose do Grupo da Febre Maculosa/diagnóstico , DNA Bacteriano/sangue , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Queensland , Rickettsia/classificação , Rickettsia/genética , Análise de Sequência de DNA , Rickettsiose do Grupo da Febre Maculosa/microbiologiaRESUMO
By conducting a molecular characterization of Corynebacterium diphtheriae strains in Australia, we identified novel sequences, nonfunctional toxin genes, and 5 recent cases of toxigenic cutaneous diphtheria. These findings highlight the importance of extrapharyngeal infections for toxin gene-bearing (functional or not) and non-toxin gene-bearing C. diphtheriae strains. Continued surveillance is recommended.
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Corynebacterium diphtheriae/patogenicidade , Toxina Diftérica/genética , Difteria/epidemiologia , Genes Bacterianos , Austrália/epidemiologia , Corynebacterium diphtheriae/genética , Difteria/imunologia , Difteria/microbiologia , Difteria/prevenção & controle , Toxina Diftérica/biossíntese , Toxoide Diftérico/administração & dosagem , Monitoramento Epidemiológico , Humanos , Extremidade Inferior/microbiologia , Extremidade Inferior/patologia , Vacinação em Massa , Mutação , Faringe/microbiologia , Faringe/patologia , Pele/microbiologia , Pele/patologiaRESUMO
During a large outbreak of Shiga toxin-producing Escherichia coli illness associated with an agricultural show in Australia, we used whole-genome sequencing to detect an IS1203v insertion in the Shiga toxin 2c subunit A gene of Shiga toxin-producing E. coli. Our study showed that clinical illness was mild, and hemolytic uremic syndrome was not detected.
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Diarreia/epidemiologia , Surtos de Doenças , Infecções por Escherichia coli/epidemiologia , Escherichia coli O157/genética , Genoma Bacteriano , Toxina Shiga I/genética , Adolescente , Adulto , Idoso , Animais , Austrália/epidemiologia , Criança , Pré-Escolar , Busca de Comunicante , Diarreia/diagnóstico , Diarreia/microbiologia , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/classificação , Escherichia coli O157/isolamento & purificação , Escherichia coli O157/patogenicidade , Fezes/microbiologia , Feminino , Cabras/microbiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Sorotipagem , Índice de Gravidade de Doença , Ovinos/microbiologia , Toxina Shiga I/classificação , Toxina Shiga I/isolamento & purificação , Sequenciamento Completo do GenomaRESUMO
Abstract: In January 2023, an outbreak of Yersinia enterocolitica in residential aged care facilities (RACF) was identified by the Gold Coast Public Health Unit and confirmed using whole genome sequencing. During the outbreak period there were 11 confirmed and 14 probable cases of Y. enterocolitica notified in RACF and 30 suspected cases with compatible illness. Eleven cases (20%) were confirmed as Biotype 1A non-typable (BT1A NT) sequence type (ST) 278 within 4-15 single nucleotide polymorphisms (SNP) of each other. Combined epidemiological, trace-back and laboratory investigations identified nutritional milkshakes, stored at ideal growing conditions for Yersinia and given to vulnerable RACF residents, as the likely outbreak vehicle. This highlights that Y. enterocolitica Biotype 1A can be pathogenic in humans and transmission via atypical sources should be considered in outbreak investigations. This report outlines the response and challenges associated with investigating outbreaks in aged care.
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Surtos de Doenças , Instituição de Longa Permanência para Idosos , Yersiniose , Yersinia enterocolitica , Humanos , Yersiniose/epidemiologia , Idoso , Yersinia enterocolitica/genética , Yersinia enterocolitica/isolamento & purificação , Sequenciamento Completo do Genoma , Idoso de 80 Anos ou mais , Polimorfismo de Nucleotídeo Único , Feminino , Masculino , Microbiologia de AlimentosRESUMO
Salmonella enterica serovar Enteritidis is one of the leading causes of salmonellosis in Australia. In this study, a total of 568 S. Enteritidis isolates from two Australian states across two consecutive years were analyzed and compared to international strains, using the S. Enteritidis multilevel genome typing (MGT) database, which contained 40,390 publicly available genomes from 99 countries. The Australian S. Enteritidis isolates were divided into three phylogenetic clades (A, B, and C). Clades A and C represented 16.4% and 3.5% of the total isolates, respectively, and were of local origin. Clade B accounted for 80.1% of the isolates which belonged to seven previously defined lineages but was dominated by the global epidemic lineage. At the MGT5 level, three out of five top sequence types (STs) in Australia were also top STs in Asia, suggesting that a fair proportion of Australian S. Enteritidis cases may be epidemiologically linked with Asian strains. In 2018, a large egg-associated local outbreak was caused by a recently defined clade B lineage prevalent in Europe and was closely related, but not directly linked, to three European isolates. Additionally, over half (54.8%) of predicted multidrug resistance (MDR) isolates belonged to 10 MDR-associated MGT-STs, which were also frequent in Asian S. Enteritidis . Overall, this study investigated the genomic epidemiology of S. Enteritidis in Australia, including the first large local outbreak, using MGT. The open MGT platform enables a standardized and sharable nomenclature that can be effectively applied to public health for unified surveillance of S. Enteritidis nationally and globally. IMPORTANCE Salmonella enterica serovar Enteritidis is a leading cause of foodborne infections. We previously developed a genomic typing database (MGTdb) for S. Enteritidis to facilitate global surveillance of this pathogen. In this study, we examined the genomic features of Australian S. Enteritidis using the MGTdb and found that Australian S. Enteritidis is mainly epidemiologically linked with Asian strains (especially strains carrying antimicrobial resistance genes), followed by European strains. The first large-scale egg-associated local outbreak in Australia was caused by a recently defined lineage prevalent in Europe, and three European isolates in the MGTdb were closely related but not directly linked to this outbreak. In summary, the S. Enteritidis MGTdb open platform is shown to be a potentially powerful tool for national and global public health surveillance of this pathogen.
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Infecções por Salmonella , Salmonella enterica , Humanos , Salmonella enteritidis/genética , Filogenia , Austrália/epidemiologia , Infecções por Salmonella/epidemiologia , GenômicaRESUMO
Here, this report presents two genomes of Vibrio cholerae O1 serotype Ogawa, recovered from cholera cases in Australia linked to travel to Pakistan in 2022. Their multidrug-resistant genotype represents the current activity of cholera within the seventh pandemic. One of the genome sequences was assembled using both short- and long-read sequences.
RESUMO
Salmonellosis is a significant public health problem globally. In Australia, Salmonella enterica serovar Enteritidis is one of the main causes of salmonellosis. This study reports how the implementation of routine genetic surveillance of isolates from human S. Enteritidis cases enabled identification of the likely source of an outbreak that occurred in a remote town in Far North Queensland, Australia. This study included patient, food and water samples collected during an outbreak investigation. S. Enteritidis of the novel sequence type 5438 was isolated from all seven patient samples and one bore water sample but not any of the food samples. Both whole-genome single nucleotide polymorphism (SNP) and core-genome multilocus sequence typing analysis revealed that S. Enteritidis isolated from outbreak-related patient samples and the bore water isolates clustered together with fewer than five SNP differences and ten allelic differences. This genetic relatedness informed the outbreak response team around public health interventions and no further cases were identified post-treatment of the bore water. This disease cluster was identified through the routine sequencing of S. Enteritidis performed by the state public health laboratory in an actionable time frame. Additionally, genomic surveillance captured a case with unknown epidemiological links to the affected community, ruled out a simultaneous outbreak in an adjacent state as the source and provided evidence for the likely source preventing further transmission. Therefore, this report provides compelling support for the implementation of whole-genome sequencing based genotyping methods in public health microbiology laboratories for better outbreak detection and management.
Assuntos
Intoxicação Alimentar por Salmonella , Infecções por Salmonella , Humanos , Salmonella enteritidis/genética , Queensland/epidemiologia , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Intoxicação Alimentar por Salmonella/epidemiologia , Surtos de Doenças , Genômica , AustráliaRESUMO
Background: Toxigenic Corynebacterium ulcerans is an emerging zoonosis globally, causing both cutaneous and respiratory diphtheria-like illness. In Queensland, human infection with toxigenic C. ulcerans is rare, with only three cases reported before October 2015. This case series describes five subsequent cases of toxigenic C. ulcerans in Queensland with links to companion animals. Methods: All data were collected as part of routine public health response, and strains were whole genome sequenced for further characterisation. Household contacts were screened, treated with appropriate antibiotics, and received a diphtheria toxoid-containing vaccine if more than five years had elapsed since their last dose. Findings: No epidemiological or genomic links could be established between any of the five patients, including between the two cases notified from the same locality within eight days of each other. The C. ulcerans strains from Cases Two, Four and Five were closely related to the strains isolated from their respective pets by whole genome sequencing. Domestic dogs were identified as the most likely mode of transmission for Cases One and Three; however, this was unable to be laboratory confirmed, since Case One's dog was treated with antibiotics before it could be tested, and Case Three's dog was euthanised and cremated prior to case notification. Interpretation: These are the first reported Australian cases of this emerging zoonosis with links to companion animals. These cases demonstrate the likely transmission route between companion animals and humans, with no evidence of human-to-human transmission. The existing requirement in the Queensland Health Public Health Management Guidelines, of restrictions on cases and some contacts while awaiting swab results, is currently under review.
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Infecções por Corynebacterium , Difteria , Humanos , Animais , Cães , Infecções por Corynebacterium/tratamento farmacológico , Infecções por Corynebacterium/epidemiologia , Infecções por Corynebacterium/veterinária , Queensland/epidemiologia , Austrália/epidemiologia , Difteria/tratamento farmacológico , Difteria/epidemiologia , Difteria/microbiologia , Zoonoses/epidemiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêuticoRESUMO
Melioidosis is an infectious disease caused by the bacterium Burkholderia pseudomallei. Although this environmental organism is endemic in certain regions of Australia, it is not considered endemic in Southern Queensland, where the last case was reported 21 years ago. We report a climate change-associated outbreak of melioidosis occurring during two La Niña events in a region previously considered nonendemic for B. pseudomallei. During a 15-month period, 14 cases of locally acquired melioidosis were identified. Twelve patients were adults (> 50 years), with diabetes mellitus the most common risk factor in 6 of 12 patients (50%). Eleven patients (79%) had direct exposure to floodwaters or the flooded environment. This study suggests an association between climate change and an increased incidence of melioidosis. In addition, this is the first report of environmental sampling and whole-genome analysis to prove endemicity and local acquisition in this region.