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1.
Int J Food Microbiol ; 340: 109042, 2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33461002

RESUMEN

The development of antimicrobial resistance in foodborne pathogens is a growing public health concern. This study was undertaken to determine the antimicrobial susceptibility of Salmonella enterica subspecies enterica isolated from the Australian commercial egg layer industry. S. enterica subspecies enterica (n=307) isolated from Australian commercial layer flock environments (2015-2018) were obtained from reference, research and State Government laboratories from six Australian states. All Salmonella isolates were serotyped. Antimicrobial susceptibility testing (AST) for 16 antimicrobial agents was performed by broth microdilution. Antimicrobial resistance genes and sequence types (STs) were identified in significant isolates by whole genome sequencing (WGS). Three main serotypes were detected, S. Typhimurium (n=61, 19.9%), S. Senftenburg (n=45, 14.7%) and S. Agona (n=37, 12.1%). AST showed 293/307 (95.4%) isolates were susceptible to all tested antimicrobial agents and all isolates were susceptible to amoxicillin-clavulanate, azithromycin, ceftiofur, ceftriaxone, ciprofloxacin, colistin, florfenicol, gentamicin, kanamycin and trimethoprim-sulfamethoxazole. Low levels of non-susceptibility were observed to streptomycin (2.3%, n=7), sulfisoxazole (2.0%, n=6), chloramphenicol (1.3%, n=4) and tetracycline (1.0%, n=3). Very low levels of non-susceptibility were observed to ampicillin (2/307; 0.7%) and cefoxitin (2/307; 0.7%). Two isolates (S. Havana and S. Montevideo), exhibited multidrug-resistant phenotypes to streptomycin, sulfisoxazole and tetracycline and possessed corresponding antimicrobial resistance genes (aadA4, aac(6')-Iaa, sul1, tetB). One S. Typhimurium isolate was resistant to ampicillin and tetracycline, and possessed both tetA and blaTEM-1B. WGS also identified these isolates as belonging to ST4 (S. Montevideo), ST578 (S. Havana) and ST19 (S. Typhimurium). The absence of resistance to highest priority critically important antimicrobials as well as the extremely low level of AMR generally among Australian commercial egg layer Salmonella isolates likely reflect Australia's conservative antimicrobial registration policy in food-producing animals and low rates of antimicrobial use within the industry.

2.
Am J Trop Med Hyg ; 2020 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-33289474

RESUMEN

Diarrhea remains a significant cause of child morbidity and mortality in Iraq. The objective of this study was to examine the current practices of home-based management of diarrheal illnesses among Iraqi children. We surveyed mothers of children aged less than 5 years to identify the sociodemographic factors associated with maternal healthcare-seeking practices. A total of 500 mother-child pairs were interviewed in a cross-sectional household survey in Thi-Qar Governorate, southeastern Iraq, between March 2016 and February 2017. Logistic and multinomial regression models were used to infer sociodemographic predictors of the healthcare-seeking and alternative management practices adopted by the mothers. The interviewees reported that 35.2% of their children had diarrhea in the 2 weeks before the survey. The least likelihood of reported occurrence of diarrhea was among mother-child pairs where the mothers had received university education, as compared with mothers who were illiterate or received only primary or secondary education. Lower odds (odds ratio = 0.4, P-value < 0.001) of reported childhood diarrhea was revealed among mothers aged > 25 years than among those younger. Self-ordered medicine from a pharmacy was the most preferred alternative management option in almost half (52.4% [262/500]) of the interviewed mothers in Thi-Qar. Interestingly, 69.6% (348/500) of the mothers reported supplying their children suffering from diarrhea with antibiotics. Relative to mothers with university education, those with high school education had more likelihood of selecting medical center (relative risk ratio [rrr] = 2.4) and pharmacy (rrr = 3.7) as against no treatment. Lower maternal educational level, mothers' age < 25 years, and the district of residence were important factors associated with diarrhea occurrence among children younger than 5 years. In light of the findings from this study, intervention aimed at improving healthcare seeking for managing diarrhea in Iraqi children should jointly consider the influence of mothers age, education, as well as the level of economic status of the communities in which mothers of these children reside. The results of this study indicate the need for enhancing public health education to improve the maternal management of diarrheal disease and the avoidance of unnecessary use of antimicrobials.

3.
Vet Microbiol ; 250: 108850, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33011663

RESUMEN

The aim of this study was to investigate antimicrobial resistance and population structure of bovine mastitis-associated Staphylococcus aureus isolates, and compare them to human isolates obtained from Western Australian hospitals and overseas strains to determine relatedness to human isolates from a zoonotic or reverse zoonotic aspect. Antimicrobial susceptibility testing was performed on 202 S. aureus isolates of which 166 isolates underwent whole genome sequencing. Only resistance to penicillin (12.4%) and erythromycin (0.5%) was identified and of note, no resistance was demonstrated to oxacillin. Genomic characterisation identified 14 multilocus sequence types (STs), with most isolates belonging to clonal complexes 97, 705, and 1. Four distinct clades based on virulence gene composition were identified. The four clades were predominantly ST based, consisting of ST352, ST97, ST81/ST1, and ST705. Core genome comparison of the bovine and human S. aureus isolates demonstrated defined clustering by ST, with the Australian bovine S. aureus isolates clustering together according to their ST separately from human isolates. In addition, a bovine specific cluster comprising Australian ST151 and ST705 isolates, and ST151 isolates from Irish dairy cattle was clearly delineated. Examination of a detailed ST352 phylogeny provided evidence for geographical clustering of Australian strains into a distinct grouping separate from international strains. This study has identified Australian S. aureus isolates have limited genetic diversity and are genetically distinct from human and international bovine S. aureus isolates. Current first line therapies for bovine mastitis in Australian dairy cattle remain appropriate.

4.
Parasitology ; 147(14): 1801-1809, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32981530

RESUMEN

Trypanosomes are blood-borne parasites that can infect a variety of different vertebrates, including animals and humans. This study aims to broaden scientific knowledge about the presence and biodiversity of trypanosomes in Australian bats. Molecular and morphological analysis was performed on 86 blood samples collected from seven different species of microbats in Western Australia. Phylogenetic analysis on 18S rDNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) sequences identified Trypanosoma dionisii in five different Australian native species of microbats; Chalinolobus gouldii, Chalinolobus morio, Nyctophilus geoffroyi, Nyctophilus major and Scotorepens balstoni. In addition, two novels, genetically distinct T. dionisii genotypes were detected and named T. dionisii genotype Aus 1 and T. dionisii genotype Aus 2. Genotype Aus 2 was the most prevalent and infected 20.9% (18/86) of bats in the present study, while genotype Aus 1 was less prevalent and was identified in 5.8% (5/86) of Australian bats. Morphological analysis was conducted on trypomastigotes identified in blood films, with morphological parameters consistent with trypanosome species in the subgenus Schizotrypanum. This is the first report of T. dionisii in Australia and in Australian native bats, which further contributes to the global distribution of this cosmopolitan bat trypanosome.

5.
Front Microbiol ; 11: 1968, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32983008

RESUMEN

Escherichia coli sequence types 131 (ST131) and 1193 are multidrug-resistant extraintestinal pathogens that have recently spread epidemically among humans and are occasionally isolated from companion animals. This study characterized a nationwide collection of fluoroquinolone-resistant (FQ R ) E. coli isolates from extraintestinal infections in Australian cats and dogs. For this, 59 cat and dog FQ R clinical E. coli isolates (representing 6.9% of an 855-isolate collection) underwent PCR-based phylotyping and whole-genome sequencing (WGS). Isolates from commensal-associated phylogenetic groups A (14/59, 24%) and B1 (18/59, 31%) were dominant, with ST224 (10/59, 17%), and ST744 (8/59, 14%) predominating. Less prevalent were phylogenetic groups D (12/59, 20%), with ST38 (8/59, 14%) predominating, and virulence-associated phylogenetic group B2 (7/59, 12%), with ST131 predominating (6/7, 86%) and no ST1193 isolates identified. In a WGS-based comparison of 20 cat and dog-source ST131 isolates with 188 reference human and animal ST131 isolates, the cat and dog-source isolates were phylogenetically diverse. Although cat and dog-source ST131 isolates exhibited some minor sub-clustering, most were closely related to human-source ST131 strains. Furthermore, the prevalence of ST131 as a cause of FQ R infections in Australian companion animals was relatively constant between this study and the 5-year-earlier study of Platell et al. (2010) (9/125 isolates, 7.2%). Thus, although the high degree of clonal commonality among FQ R clinical isolates from humans vs. companion animals suggests the possibility of bi-directional between-species transmission, the much higher reported prevalence of ST131 and ST1193 among FQ R clinical isolates from humans as compared to companion animals suggests that companion animals are spillover hosts rather than being a primary reservoir for these lineages.

6.
Vet Microbiol ; 248: 108783, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32827920

RESUMEN

This study investigated the prevalence of extraintestinal pathogenic E. coli (ExPEC)-associated sequence types (STs) from phylogenetic group B2 among 449 fluoroquinolone-susceptible dog clinical isolates from Australia. Isolates underwent PCR-based phylotyping and random amplified polymorphic DNA analysis to determine clonal relatedness. Of the 317 so-identified group B2 isolates, 77 underwent whole genome sequencing (WGS), whereas the remainder underwent PCR-based screening for ST complexes (STc) STc12, STc73, STc372, and ST131. The predominant ST was ST372 according to both WGS (31 % of 77) and ST-specific PCR (22 % of 240), followed by (per WGS) ST73 (17 %), ST12 (7 %), and ST80 (7 %). A WGS-based phylogenetic comparison of ST73 isolates from dogs, cats, and humans showed considerable overall phylogenetic diversity. Although most clusters were species-specific, some contained closely related human and animal (dog > cat) isolates. For dogs in Australia these findings both confirm ST372 as the predominant E. coli clonal lineage causing extraintestinal infections and clarify the importance of human-associated group B2 lineage ST73 as a cause of UTI, with some strains possibly being capable of bi-directional (i.e., dog-human and human-dog) transmission.

7.
Appl Environ Microbiol ; 86(20)2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32801178

RESUMEN

Globally, gulls have been associated with carriage of high levels of Escherichia coli strains resistant to critically important antimicrobials (CIAs), a major concern, as these antimicrobials are the sole alternative or one among only a few alternatives available to treat severe life-threatening infections in humans. Previous studies of Australian silver gulls demonstrated high levels of resistance to CIAs, particularly fluoroquinolone and extended-spectrum cephalosporins, among E. coli strains (carriage at 24% and 22%, respectively). This study aimed to identify and characterize strains from four distinct bird species inhabiting a common coastal environment, determine the frequency of carriage of CIA-resistant E. coli strains, and examine if these resistant clones and their resistance-encoding mobile genetic elements (MGEs) could be transmitted between species. CIA-resistant E. coli was detected in silver gulls (53%), little penguins (11%), and feral pigeons (10%), but not in bridled terns. In total, 37 different sequence types (STs) were identified, including clinically significant human-associated lineages, such as ST131, ST95, ST648, ST69, ST540, ST93, ST450, and ST10. Five main mobile genetic elements associated with bla CTX-M-positive E. coli strains isolated from three bird species were detected. Examination of clonal lineages and MGEs provided indirect evidence of transfer of resistance between bird species. The carriage of CIA-resistant E. coli by gulls and pigeons with proximity to humans, and in some instances food-producing animals, increases the likelihood of further bidirectional dissemination.IMPORTANCE It has been shown that 20% of Australian silver gulls carry drug-resistant Escherichia coli strains of anthropogenic origin associated with severe diseases, such as sepsis and urinary tract infections, in humans. To further characterize the dynamics of drug-resistant E. coli in wildlife populations, we investigated the carriage of critically important antimicrobial (CIA) drug-resistant E. coli in four bird species in a common environment. Our results indicated that gulls, pigeons, and penguins carried drug-resistant E. coli strains, and analysis of mobile genetic elements associated with resistance genes indicated interspecies resistance transfer. Terns, representing a bird species that forages on natural food sources at sea and distant from humans, did not test positive for drug-resistant E. coli This study demonstrates carriage of CIA-resistant bacteria in multiple bird species living in areas commonly inhabited by humans and provides further evidence for a leapfrog effect of resistance in wildlife, facilitated by feeding habits.

8.
Microorganisms ; 8(5)2020 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-32403447

RESUMEN

Cryptosporidium is a major cause of severe diarrhea-related disease in children in developing countries, but currently no vaccine or effective treatment exists for those who are most at risk of serious illness. This is partly due to the lack of in vitro culturing methods that are able to support the entire Cryptosporidium life cycle, which has led to research in Cryptosporidium biology lagging behind other protozoan parasites. In vivo models such as gnotobiotic piglets are complex, and standard in vitro culturing methods in transformed cell lines, such as HCT-8 cells, have not been able to fully support fertilization occurring in vitro. Additionally, the Cryptosporidium life cycle has also been reported to occur in the absence of host cells. Recently developed bioengineered intestinal models, however, have shown more promising results and are able to reproduce a whole cycle of infectivity in one model system. This review evaluates the recent advances in Cryptosporidium culturing techniques and proposes future directions for research that may build upon these successes.

9.
Vet Microbiol ; 245: 108685, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32456818

RESUMEN

Extraintestinal pathogenic Escherichia coli (ExPEC) can cause urinary tract and other types of infection in cats, but the relationship of cat ExPEC to human ExPEC remains equivocal. This study investigated the prevalence of ExPEC-associated sequence types (STs) from phylogenetic group B2 among fluoroquinolone-susceptible cat clinical isolates. For this, 323 fluoroquinolone-susceptible cat clinical E. coli isolates from Australia underwent PCR-based phylotyping and random amplified polymorphic DNA analysis to determine clonal relatedness. Of the 274 group B2 isolates, 53 underwent whole genome sequencing (WGS), whereas 221 underwent PCR-based screening for (group B2) sequence type complexes (STc) STc12, STc73, ST131, and STc372. Group B2 was the dominant phylogenetic group (274/323, 85 %), whereas within group B2 ST73 dominated, according to both WGS (43 % of 53; followed by ST127, ST12, and ST372 [4/53, 8 % each]) and ST-specific PCR (20 % of 221). In WGS-based comparisons of cat and reference human ST73 isolates, cat isolates had a relatively conserved virulence gene profile but were phylogenetically diverse. Although in the phylogram most cat and human ST73 isolates occupied host species-specific clusters within serotype-specific clades (O2:H1, O6:H1, O25:H1, O50/O2:H1), cat and human isolates were intermingled within two serotype-specific clades: O120:H31 (3 cat and 2 human isolates) and O22:H1 (3 cat and 5 human isolates). These findings confirm the importance of human-associated group B2 lineages as a cause of urinary tract infections in cats. The close genetic relationship of some cat and human ST73 strains suggests bi-directional transmission may be possible.

10.
Zoonoses Public Health ; 67(5): 576-586, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32458580

RESUMEN

This observational study aimed to determine MRSA prevalence using strain-specific real-time PCR at the pig level, stratified by age groupings, within a pig enterprise. A total of 658 samples were collected from individual pigs (n = 618) and the piggery environment (n = 40), distributed amongst five different pig age groups. Presumptive MRSA isolates were confirmed by the presence of mecA, and MALDI-TOF was performed for species verification. All isolates were tested against 18 different antimicrobials. MRSA was isolated from 75.2% (95% CI 71.8-78.6) of samples collected from pigs, and 71% of the MRSA isolates from this source were identified as community-associated (CA)-MRSA ST93, while the remainder were livestock-associated (LA)-MRSA ST398. Amongst environmental isolates, 80% (CI 64.3-95.7) were ST93 and the remainder ST398. All MRSA isolates from pigs and the environment were susceptible to ciprofloxacin, gentamicin, linezolid, mupirocin, rifampicin, sulfamethoxazole-trimethoprim, teicoplanin and vancomycin. Phenotypic rates of resistance were penicillin (100%), clindamycin (97.6%), erythromycin (96.3%), ceftiofur (93.7%), chloramphenicol (81.2%), tetracycline (63.1%) and amoxicillin-clavulanate (63.9%). A low prevalence of resistance (9.2%) was observed against neomycin and quinupristin-dalfopristin. The probability of MRSA carriage in dry sows (42.2%) was found to be significantly lower (p < .001) when compared to other age groups: farrowing sows (76.8%, RR1.82), weaners (97.8%, RR 2.32), growers (94.2%, RR 2.23) and finishers (98.3%, RR 2.33). Amongst different production age groups, a significant difference was also found in antimicrobial resistance for amoxicillin-clavulanate, neomycin, chloramphenicol and tetracycline. Using the RT-PCR assay adopted in this study, filtering of highly prevalent ST93 and non-ST93 isolates was performed at high throughput and low cost. In conclusion, this study found that weaner pigs presented a higher risk for CA-MRSA and antimicrobial resistance compared to other age groups. These findings have major implications for how investigations of MRSA outbreaks should be approached under the One-Health context.

11.
Pathogens ; 9(5)2020 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-32422856

RESUMEN

Streptococcus suis is a swine pathogen and a zoonotic agent afflicting people in close contact with infected pigs or pork meat. Sporadic cases of human infections have been reported worldwide. In addition, S. suis outbreaks emerged in Asia, making this bacterium a primary health concern in this part of the globe. In pigs, S. suis disease results in decreased performance and increased mortality, which have a significant economic impact on swine production worldwide. Facing the new regulations in preventive use of antimicrobials in livestock and lack of effective vaccines, control of S. suis infections is worrisome. Increasing and sharing of knowledge on this pathogen is of utmost importance. As such, the pathogenesis and epidemiology of the infection, antimicrobial resistance, progress on diagnosis, prevention, and control were among the topics discussed during the 4th International Workshop on Streptococcus suis (held in Montreal, Canada, June 2019). This review gathers together recent findings on this important pathogen from lectures performed by lead researchers from several countries including Australia, Canada, France, Germany, Japan, Spain, Thailand, The Netherlands, UK, and USA. Finally, policies and recommendations for the manufacture, quality control, and use of inactivated autogenous vaccines are addressed to advance this important field in veterinary medicine.

12.
Appl Environ Microbiol ; 86(8)2020 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-32033955

RESUMEN

In a structured survey of all major chicken-meat producers in Australia, we investigated the antimicrobial resistance (AMR) and genomic characteristics of Campylobacter jejuni (n = 108) and C. coli (n = 96) from cecal samples of chickens at slaughter (n = 200). The majority of the C. jejuni (63%) and C. coli (86.5%) samples were susceptible to all antimicrobials. Fluoroquinolone resistance was detected among both C. jejuni (14.8%) and C. coli (5.2%), although this only included three sequence types (STs) and one ST, respectively. Multidrug resistance among strains of C. jejuni (0.9%) and C. coli (4.1%) was rare, and fluoroquinolone resistance, when present, was never accompanied by resistance to any other agent. Comparative genome analysis demonstrated that Australian isolates were found dispersed on different branches/clusters within the international collection. The major fluoroquinolone-resistant STs of C. jejuni (ST7323, ST2083, and ST2343) and C. coli (ST860) present in Australian chickens were similar to those of international isolates and have been reported previously in humans and animals overseas. The detection of a subpopulation of Campylobacter isolates exclusively resistant to fluoroquinolone was unexpected since most critically important antimicrobials such as fluoroquinolones are excluded from use in Australian livestock. A number of factors, including the low level of resistance to other antimicrobials, the absence of fluoroquinolone use, the adoption of measures for preventing spread of contagion between flocks, and particularly the genomic identities of isolates, all point to humans, pest species, or wild birds as being the most plausible source of organisms. This study also demonstrates the need for vigilance in the form of surveillance for AMR based on robust sampling to manage AMR risks in the food chain.IMPORTANCE Campylobacter is one of the most common causes of gastroenteritis in humans, with infections frequently resulting from exposure to undercooked poultry products. Although human illness is typically self-limiting, a minority of cases do require antimicrobial therapy. Ensuring that Campylobacter originating from meat chickens does not acquire resistance to fluoroquinolones is therefore a valuable outcome for public health. Australia has never legalized the use of fluoroquinolones in commercial chickens and until now fluoroquinolone-resistant Campylobacter has not been detected in the Australian poultry. This structured survey of meat chickens derived from all major Australian producers describes the unexpected emergence of fluoroquinolone resistance in Campylobacter jejuni and C. coli Genetic characterization suggests that these isolates may have evolved outside the Australian poultry sector and were introduced into poultry by humans, pest species, or wild birds. The findings dramatically underline the critical role of biosecurity in the overall fight against antimicrobial resistance.


Asunto(s)
Antibacterianos/farmacología , Infecciones por Campylobacter/veterinaria , Campylobacter coli/efectos de los fármacos , Campylobacter jejuni/efectos de los fármacos , Farmacorresistencia Bacteriana , Fluoroquinolonas/farmacología , Enfermedades de las Aves de Corral/epidemiología , Animales , Australia/epidemiología , Infecciones por Campylobacter/epidemiología , Infecciones por Campylobacter/microbiología , Campylobacter coli/fisiología , Campylobacter jejuni/fisiología , Pollos , Pruebas de Sensibilidad Microbiana , Enfermedades de las Aves de Corral/microbiología
13.
Sci Rep ; 10(1): 3757, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32094432

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

15.
Viruses ; 11(12)2019 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-31847282

RESUMEN

Bats are known reservoirs of a wide variety of viruses that rarely result in overt clinical disease in the bat host. However, anthropogenic influences on the landscape and climate can change species assemblages and interactions, as well as undermine host-resilience. The cumulative result is a disturbance of bat-pathogen dynamics, which facilitate spillover events to sympatric species, and may threaten bat communities already facing synergistic stressors through ecological change. Therefore, characterisation of viral pathogens in bat communities provides important basal information to monitor and predict the emergence of diseases relevant to conservation and public health. This study used targeted molecular techniques, serological assays and next generation sequencing to characterise adenoviruses, coronaviruses and paramyxoviruses from 11 species of insectivorous bats within the South West Botanical Province of Western Australia. Phylogenetic analysis indicated complex ecological interactions including virus-host associations, cross-species infections, and multiple viral strains circulating concurrently within selected bat populations. Additionally, we describe the entire coding sequences for five alphacoronaviruses (representing four putative new species), and one novel adenovirus. Results indicate that viral burden (both prevalence and richness) is not homogeneous among species, with Chalinolobus gouldii identified as a key epidemiological element within the studied communities.


Asunto(s)
Biodiversidad , Quirópteros/virología , Adenoviridae/clasificación , Adenoviridae/genética , Adenoviridae/inmunología , Adenoviridae/aislamiento & purificación , Animales , Quirópteros/clasificación , Coronavirus/clasificación , Coronavirus/genética , Coronavirus/inmunología , Coronavirus/aislamiento & purificación , Heces/virología , Conducta Alimentaria , Genoma Viral/genética , Paramyxovirinae/clasificación , Paramyxovirinae/genética , Paramyxovirinae/inmunología , Paramyxovirinae/aislamiento & purificación , Filogenia , Análisis de Secuencia , Estudios Seroepidemiológicos , Especificidad de la Especie , Proteínas Virales/genética , Proteínas Virales/inmunología , Australia Occidental/epidemiología
16.
Sci Rep ; 9(1): 16562, 2019 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-31719565

RESUMEN

An understanding of the core demographic characteristics of the sub-populations of FRD is essential to effectively implement both rabies control interventions through mass vaccination of FRD, and dog population control programmes. This study compares the data obtained following photographic sight-resight surveys in rural (Shirsuphal village in west India) and urban (Municipal Corporation Panchkula in north India) locations . A total of 263 and 1408  FRD were seen at least once through 617 and 3465 sightings in the rural and urban sites, respectively. The rural location had a lower proportion of females (OR 0.5, 95% CI 0.4-0.7) and a higher proportion of poor and fair conditioned dogs (OR 1.8, 95% CI 1.3-2.3) compared to the urban setting. The rural site also had fewer active FRD (OR 0.6, 95% CI 0.5-0.7) and FRD were less likely to be sighted within 20 m of garbage points (OR 0.3, 95% CI 0.2-0.3) compared to the urban site. The demographic composition of the FRD population was found to vary within the urban location, with the odds of sighting a de-sexed dog being significantly higher in residential areas compared to other areas. The study underlines the importance of knowing the demographic composition of FRD for implementation of effective interventions against rabies. Fewer female dogs in the rural location indicate that spaying could be an effective tool for dog population management in this setting, while presence of dogs within 20 m of garbage points in urban settings highlights that an improved garbage management may reduce the carrying capacity of the urban locality resulting in smaller FRD population. It is concluded that quick and low cost surveys can generate useful demographic data for FRD in urban and rural settings which can be useful to understand the epidemiology of rabies and its control.


Asunto(s)
Demografía , Fotograbar , Población Rural , Encuestas y Cuestionarios , Población Urbana , Animales , Perros , Femenino , India/epidemiología , Masculino
17.
PLoS One ; 14(10): e0224281, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31644602

RESUMEN

The World Health Organisation has defined "highest priority critically important antimicrobials" (CIAs) as those requiring the greatest control during food production. Evidence demonstrating that restricted antimicrobial usage prevents the emergence of resistance to CIA's amongst pathogenic and commensal organisms on a production system-wide scale would strengthen international efforts to control antimicrobial resistance (AMR). Therefore, in a designed survey of all major chicken-meat producers in Australia, we investigated the phenotypic AMR of E. coli (n = 206) and Salmonella (n = 53) from caecal samples of chickens at slaughter (n = 200). A large proportion of E. coli isolates (63.1%) were susceptible to all tested antimicrobials. With regards to CIA resistance, only two E.coli isolates demonstrated resistance to fluoroquinolones, attributed to mutations in the quinolone resistance-determining regions of gyrA. Antimicrobial resistance was observed for trimethoprim/sulfamethoxazole (8.7%), streptomycin (9.7%), ampicillin (14.1%), tetracycline (19.4%) and cefoxitin (0.5%). All Salmonella isolates were susceptible to ceftiofur, chloramphenicol, ciprofloxacin, colistin, florfenicol, gentamicin and tetracycline. A low frequency of Salmonella isolates exhibited resistance to streptomycin (1.9%), ampicillin (3.8%), and cefoxitin (11.3%). AMR was only observed among Salmonella Sofia serovars. None of the Salmonella isolates exhibited a multi-class-resistant phenotype. Whole genome sequencing did not identify any known resistance mechanisms for the Salmonella isolates demonstrating resistance to cefoxitin. The results provide strong evidence that resistance to highest priority CIA's is absent in commensal E. coli and Salmonella isolated from Australian meat chickens, and demonstrates low levels of resistance to compounds with less critical ratings such as cefoxitin, trimethoprim/sulfamethoxazole, and tetracycline. Apart from regulated exclusion of CIAs from most aspects of livestock production, vaccination against key bacterial pathogens and stringent biosecurity are likely to have contributed to the favorable AMR status of the Australian chicken meat industry. Nevertheless, industry and government need to proactively monitor AMR and antimicrobial stewardship practices to ensure the long-term protection of both animal and human health.


Asunto(s)
Antibacterianos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Carne/microbiología , Salmonella/efectos de los fármacos , Salmonella/aislamiento & purificación , Animales , Australia , Pollos/microbiología , Farmacorresistencia Bacteriana , Escherichia coli/genética , Microbiología de Alimentos , Salmonella/genética , Secuenciación Completa del Genoma
18.
Vaccines (Basel) ; 7(4)2019 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-31575061

RESUMEN

Adequate vaccination coverage of free roaming dogs (FRD) against canine rabies is not achieved primarily due to difficulties in administering parenteral vaccinations to this population. One factor associated with this difficulty is the tendency of FRD to form groups, which increases their aggressive behavior, resulting in a significant risk of dog-bites for the vaccinators. This study investigated factors that influenced FRD forming groups and their home-ranges, using data obtained from photographic capture-recapture/sight-resight surveys conducted in rural Shirsuphal (584 sightings) and urban Panchkula (3208 sightings), India. In the rural site, older dogs (OR 0.5, 95% CI 0.2-0.9, p = 0.03) and FRD sighted within 20 m of garbage sites (OR 0.6, 95% CI 0.4-0.9, p = 0.02) were less likely to be in groups. The number of dogs sighted with an FRD decreased with increased resight-probability of that dog (ß= -1.0, p < 0.001). The rural FRD with smaller home-ranges were more likely to be sighted alone (OR 2.3, 95% CI 1.0-95, p = 0.04) than those with larger home-ranges. In the urban site, females (OR 1.3, 95% CI 1.1-1.5, p = 0.002) and older dogs (OR 1.5, 95% CI 1.1-2.1, p = 0.07) were more likely to be found in groups, and groups of dogs were more likely to be seen within 20 meters of garbage sites (OR 1.7, 95% CI 1.5-2.0, p < 0.001). The distribution of urban FRD sighted alone, in pairs, triads, and in packs of ≥4 dogs were not random in the administrative (p = 0.02), and the two industrial (p = 0.03 & 0.01) survey tracks of the urban site, implying stable groups. The resighting probability of a dog (ß = 0.3, p < 0.0001) and presence of garbage within 20 m (ß = 0.2, p < 0.0001) in the urban site increased the likelihood of sighting a FRD with other dogs. It is concluded that data on the resighting probability, presence of garbage points, and home-ranges can be utilised to guide the selection of parenteral or oral rabies vaccination to achieve a population vaccination coverage of 70% to break the transmission cycle of rabies virus in FRD in India.

19.
J Anim Sci ; 97(11): 4503-4508, 2019 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-31545364

RESUMEN

An infection model with enterotoxigenic Escherichia coli (ETEC) harboring the F4 fimbriae can be used to assess the impacts that various challenges associated with weaning (e.g., dietary, psychological, environmental) have on the expression of postweaning diarrhea. The objective of this study was to develop a novel inoculation method for administering an ETEC culture that would induce a higher proportion of ETEC-F4 diarrhea, in pigs that genetically showed ETEC-F4 susceptibility or resistance. The study was designed as a factorial arrangement of treatments with the factors being 1) partially susceptible or resistant to ETEC-F4 based on genetic testing, and 2) 4 challenge treatments, being a) a conventional liquid broth method using a drenching gun [Positive control (PC)], b) a Syringe method, c) a Capsule method, and d) Negative control [pigs not challenged (NC)]. At 21 ± 3 d of age (mean ± SEM), 48 male castrate pigs (Large White × Landrace) weighing approximately 7.0 ± 1.18 kg were allocated to 4 treatment groups in 2 replicate pens (6 pigs per pen). Initial ETEC-F4 susceptibility was based on a DNA marker test and each treatment group had 9 partially susceptible and 3 resistant pigs. On days 7 and 8 after weaning, pigs were challenged with ETEC (serotype O149:K88; toxins LT1, ST1, ST2, and EAST). On each inoculation day the PC pigs were orally dosed with 9 mL 7.12 × 109 colony-forming unit (CFU), the Syringe pigs with 0.8 mL 6.72 × 109 CFU, the Capsule pigs were orally administered 2 capsules containing 0.8 mL 3.28 × 109 CFU, and the NC pigs 1 mL of phosphate-buffered saline (PBS) solution. Approximately 72 h after infection, 44, 22, 78, and 0% of partially susceptible pigs in the PC, the Syringe, the Capsule, and the NC group had developed ETEC-F4 diarrhea (P = 0.007). Partially susceptible pigs had a higher diarrhea index (DI) compared to resistant pigs (31.5 vs. 4.8, P < 0.001). The NC group had a lower DI compared to the PC and Capsule pigs (3.9, 38.1, and 40.3, respectively, P < 0.005). Following infection, genetically resistant pigs in the Capsule group had a DI of zero and the partially susceptible pigs had a DI of 55.6 (P = 0.014). This study showed that genetically screening pigs and using a Capsule to deliver ETEC-F4 can increase cases of diarrhea and the efficiency of the challenge model. Taken together, these methods have the potential to reduce the number of pigs needed in future experimental infection studies.


Asunto(s)
Diarrea/veterinaria , Modelos Animales de Enfermedad , Escherichia coli Enterotoxigénica/fisiología , Infecciones por Escherichia coli/veterinaria , Enfermedades de los Porcinos/microbiología , Porcinos , Animales , Infecciones por Escherichia coli/microbiología , Sitios Genéticos , Masculino , Destete
20.
Int J Food Microbiol ; 308: 108305, 2019 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-31476731

RESUMEN

In recent years, the number of human salmonellosis cases in Western Australia (WA) has increased more dramatically than in any other Australian state. In 2017, the number of cases in WA was more than double the five-year average, and eggs had emerged as the key culprit for several Salmonella foodborne disease outbreaks. To better understand such an epidemiologically intriguing situation, our research goal was to investigate the prevalence, serovar diversity, multilocus sequence types, and antimicrobial resistance of non-typhoidal Salmonella contamination in retail eggs produced and sold in WA. A total of 200 visually clean and intact retail egg samples (each containing a dozen eggs) were purchased for one year (2017-2018) from supermarkets in metropolitan Perth, the capital of WA. For each sample, the contents and shells of the 12 eggs were separately pooled and cultured according to standard methods. Overall, Salmonella was detected in 11.5% (23/200) of the tested egg samples. Salmonella was isolated from 4.5% (9/200) and 3% (6/200) of eggshells and egg contents, respectively. In 4% (8/200) of the samples, Salmonella was recovered from both eggshell and egg contents. Isolates from positive retail egg samples were serotyped as either S. Typhimurium (52.2% [12/23]) or S. Infantis (39.1% [9/23]). Both serotypes were concurrently recovered from two different retail egg samples. We retained a set of both S. Typhimurium (n = 29) and S. Infantis (n = 12) isolates from all Salmonella-positive retail packs (n = 23) for further characterization. Only two (S. Typhimurium) isolates showed resistance to ampicillin, of which one carried ß-lactamase resistance gene blaTEM-1b. The remaining isolates (39/41) were susceptible to all 14 antimicrobials included in the minimum inhibitory concentrations (MICs) testing panel. Multilocus sequence typing and serotyping were perfectly mirrored, as all S. Typhimurium isolates were characterized as sequence type (ST)-19, and all S. Infantis isolates were ST-32. This study points to the noteworthy Salmonella prevalence rate in retail egg samples in WA. Our results illustrate minimal public health risks arising from antimicrobial resistance Salmonella from Australian eggs.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Cáscara de Huevo/microbiología , Huevos/microbiología , Microbiología de Alimentos/métodos , Salmonella/aislamiento & purificación , Animales , Australia , Genómica , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Salmonella/clasificación , Salmonella/genética , Intoxicación Alimentaria por Salmonella/epidemiología , Infecciones por Salmonella/epidemiología , Serogrupo , Serotipificación , Australia Occidental/epidemiología
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