Genetic characterization of duck hepatitis B viruses from Anhui Province, China.

Duck hepatitis B virus (DHBV) infection model was frequently used as the experimental model for human hepatitis B virus (HBV) research. In order to decipher the genetic characteristics of DHBVs from Anhui province of China, 120 duck liver tissue samples were collected and subjected to PCR screening, and 28 samples were detected as DHBV positive. Subsequently, five DHBV-positive samples were selected for genome-wide amplification and a comprehensive analysis. Comparative analysis of complete genome sequences using the MegAlign program showed that five strains of DHBVs shared 94.5-96.3% with each other and 93.2-98.7% with other reference strains in GenBank. The phylogenetic analysis showed that all five DHBV strains belonged to the evolutionary branch of "Chinese DHBV" isolates or DHBV-2. Importantly, three potential intra-genotypic recombination events, between strains AAU-6 and Guilin, strains AAU-1 and GD3, and strains AAU-6 and AAU-1, were respectively found using the RDP and SimPlot softwares and considered the first report in avihepadnaviruses. These results not only improve our understanding for molecular prevalence status of DHBV among ducks, but also provide a reference for recombination mechanism of HBV.

Occurrence of Avian Mycoplasmas in Free-Living Muscovy-Ducks (Cairina Moschata)

The present study aimed to investigate, by culture and PCR, the occurrence of Mollicutes, Mycoplasma gallisepticum and Mycoplasma synoviae in free-living Muscovy-ducks (Cairina moschata) from the Rio Zoo, RJ, Brazil. Tracheal swabs were obtained from 82 asymptomatic ducks and the samples were submitted to culture of mycoplasmas and PCR for identification of Mollicutes Class, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). Samples were also analyzed directly by PCR, without prior culture, for Mollicutes, MG and MS. Eighteen (18/82) Muscovy-ducks were positive for Mollicutes by culture, all isolates were confirmed as Mollicutes and seven were identified as MG. Of the samples analyzed directly by PCR, without prior culture, 17,1% (14/82) was positive for Mollicutes, being 35,7% (5/14) identified as MG and 21,4% (3/14) as MS. The occurrence of Mollicutes class bacteria was detected in Muscovy-ducks. MG and MS were identified in these animals suggesting the circulation of these agents in the Rio de Janeiro Zoo and may present a risk for the health status of the other birds.(AU)

Occurrence of Avian Mycoplasmas in Free-Living Muscovy-Ducks (Cairina Moschata)

The present study aimed to investigate, by culture and PCR, the occurrence of Mollicutes, Mycoplasma gallisepticum and Mycoplasma synoviae in free-living Muscovy-ducks (Cairina moschata) from the Rio Zoo, RJ, Brazil. Tracheal swabs were obtained from 82 asymptomatic ducks and the samples were submitted to culture of mycoplasmas and PCR for identification of Mollicutes Class, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). Samples were also analyzed directly by PCR, without prior culture, for Mollicutes, MG and MS. Eighteen (18/82) Muscovy-ducks were positive for Mollicutes by culture, all isolates were confirmed as Mollicutes and seven were identified as MG. Of the samples analyzed directly by PCR, without prior culture, 17,1% (14/82) was positive for Mollicutes, being 35,7% (5/14) identified as MG and 21,4% (3/14) as MS. The occurrence of Mollicutes class bacteria was detected in Muscovy-ducks. MG and MS were identified in these animals suggesting the circulation of these agents in the Rio de Janeiro Zoo and may present a risk for the health status of the other birds.

Effect of bacterial endotoxin lipopolysaccharide treatment on duck Leydig cells

This study aimed to investigate the effects of bacterial endotoxin lipopolysaccharide (LPS) on hormone production and gene expression in duck Leydig cells and its underlying mechanisms. Leydig cells were collected from 200-day-old mallard ducks and divided into five treatment groups (0, 50, 100, 200, and 400 ng/mL LPS). After treatment with LPS for 6, 12, 24, and 48 h, testosterone, activin, and inhibin levels in the cell supernatants were determined using enzyme-linked immunosorbent assay (ELISA) kits. The expression levels of testosterone synthesis-related genes, including steroidogenic acute regulatory protein (StAR), 3-beta-hydroxysteroid dehydrogenase (3β-HSD), and cytochrome P450 aromatase (P450arom), and reproductive-related genes, including gonadotropin-inhibitory hormone receptor (GnIHR), follicle stimulating hormone receptor (FSHR), and luteinizing hormone receptor (LHR) were detected using quantitative real-time polymerase chain reaction (qRT-PCR). We successfully isolated and cultured duck Leydig cells with cell purity above 90%. Compared with the control group, the levels of testosterone, activin, and inhibin secreted in Leydig cells decreased gradually with increasing LPS concentration. After treatment with LPS, the expression of StAR and 3β-HSD genes in Leydig cells was upregulated at 12 h, and that of GnIHR was upregulated at 24 h; whereas the expression of FSHR and LHR was reduced at 24 h. This study indicates that LPS can inhibit the secretion of hormones and regulate the expression of related genes in duck Leydig cells.(AU)

Effect of bacterial endotoxin lipopolysaccharide treatment on duck Leydig cells

This study aimed to investigate the effects of bacterial endotoxin lipopolysaccharide (LPS) on hormone production and gene expression in duck Leydig cells and its underlying mechanisms. Leydig cells were collected from 200-day-old mallard ducks and divided into five treatment groups (0, 50, 100, 200, and 400 ng/mL LPS). After treatment with LPS for 6, 12, 24, and 48 h, testosterone, activin, and inhibin levels in the cell supernatants were determined using enzyme-linked immunosorbent assay (ELISA) kits. The expression levels of testosterone synthesis-related genes, including steroidogenic acute regulatory protein (StAR), 3-beta-hydroxysteroid dehydrogenase (3β-HSD), and cytochrome P450 aromatase (P450arom), and reproductive-related genes, including gonadotropin-inhibitory hormone receptor (GnIHR), follicle stimulating hormone receptor (FSHR), and luteinizing hormone receptor (LHR) were detected using quantitative real-time polymerase chain reaction (qRT-PCR). We successfully isolated and cultured duck Leydig cells with cell purity above 90%. Compared with the control group, the levels of testosterone, activin, and inhibin secreted in Leydig cells decreased gradually with increasing LPS concentration. After treatment with LPS, the expression of StAR and 3β-HSD genes in Leydig cells was upregulated at 12 h, and that of GnIHR was upregulated at 24 h; whereas the expression of FSHR and LHR was reduced at 24 h. This study indicates that LPS can inhibit the secretion of hormones and regulate the expression of related genes in duck Leydig cells.

Genomics of Salmonella contaminating backyard production systems reveals persistence and transmission of genetically related Salmonella on a farm basis.

Animals raised in backyard productive systems (BPS) have been frequently associated with Salmonella outbreaks. Several serovars have caused these events, showing that different BPSs can be contaminated by distinct Salmonella serovars. The aim of this study was to characterize the genomic diversity of Salmonella isolates obtained from BPSs in Central Chile to understand their genomic relatedness. A whole-genome SNP-based phylogenetic analysis of 22 Salmonella isolates from 12 locations revealed that S. Typhimurium isolates clustered based on the BPS that they were originally isolated from, and the same was established for S. Enteritidis isolates. Furthermore, our genomic analysis shows that animals from different species (i.e., a chicken, a duck and a pig) carried genetically related S. Typhimurium strains within the same BPS. Moreover, some of these genetically related isolates were obtained in different years (2013 and 2014), indicating that farm-specific Salmonella can persist in BPSs for multiple years and that interspecies transmission is plausible in this environment. Understanding the dynamics of interspecies transmission of Salmonella serovars within a contaminated BPS is fundamental to the design of mitigation strategies to reduce outbreaks of human Salmonella associated with backyard production systems.

SPM-1-producing Pseudomonas aeruginosa ST277 clone recovered from microbiota of migratory birds.

The production of São Paulo metallo-ß-lactamase (SPM-1) is the most common carbapenem resistance mechanism detected among multidrug-resistant Pseudomonas aeruginosa clinical isolates in Brazil. Dissemination of SPM-1-producing P. aeruginosa has been restricted to the nosocomial settings, with sporadic reports of environmental isolates due to contamination by hospital sewage. Herein, we described the detection and molecular characterization of SPM-1-producing P. aeruginosa recovered from the microbiota of migratory birds in Brazil. Three hundred gram-negative bacilli were recovered from cloacal and choanal swabs of Dendrocygna viduata during a surveillance study for detection of carbapenem-resistant isolates. All isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. MICs were determined by agar dilution, except for polymyxin B. Antibiotic resistance genes were detected by polymerase chain reaction (PCR) followed by DNA sequencing. Transcriptional levels of oprD and efflux system encoding genes were also carried out by quantitative real-time PCR. Nine imipenem-resistant P. aeruginosa isolates were recovered with 7 of them carrying blaSPM-1. Additional resistance genes (rmtD-1, blaOXA-56,aacA4, and aac(6')-Ib-cr) were also detected in all 9 isolates. The SPM-1-producing isolates showed high MICs for all ß-lactams, fluoroquinolones, and aminoglycosides, being susceptible only to polymyxin B. Interestingly, all isolates showed the same PFGE pattern and belonged to ST277. Overexpression of MexXY-OprM and MexAB-OprM was observed in those isolates that did not harbor blaSPM-1. Our results suggest that migratory birds might have played a role in the dissemination of SPM-1-producing P. aeruginosa within the Brazilian territory.

First detection and characterization of Salmonella spp. in poultry and swine raised in backyard production systems in central Chile.

Little is known about Salmonella serovars circulating in backyard poultry and swine populations worldwide. Backyard production systems (BPS) that raise swine and/or poultry are distributed across Chile, but are more heavily concentrated in central Chile, where industrialized systems are in close contact with BPS. This study aims to detect and identify circulating Salmonella serovars in poultry and swine raised in BPS. Bacteriological Salmonella isolation was carried out for 1744 samples collected from 329 BPS in central Chile. Faecal samples were taken from swine, poultry, geese, ducks, turkeys and peacocks, as well as environmental faecal samples. Confirmation of Salmonella spp. was performed using invA-polymerase chain reaction (PCR). Identification of serovars was carried out using a molecular serotyping approach, where serogroups were confirmed by a multiplex PCR of Salmonella serogroup genes for five Salmonella O antigens (i.e., D, B, C1, C2-C3, and E1), along with two PCR amplifications, followed by sequencing of fliC and fljB genes. A total of 25 samples (1·4% of total samples) from 15 BPS (4·6 % of total sampled BPS) were found positive for Salmonella. Positive samples were found in poultry (chickens and ducks), swine and environmental sources. Molecular prediction of serovars on Salmonella isolated showed 52·0% of S. Typhimurium, 16·0% of S. Infantis, 16·0% S. Enteritidis, 8·0% S. Hadar, 4·0% S. Tennessee and 4·0% S. Kentucky. Poor biosecurity measures were found on sampled BPS, where a high percentage of mixed confinement systems (72·8%); and almost half of the sampled BPS with improper management of infected mortalities (e.g. selling the carcasses of infected animals for consumption). Number of birds other than chickens (P = 0·014; OR = 1·04; IC (95%) = 1·01-1·07), mixed productive objective (P = 0·030; OR = 5·35; IC (95%) = 1·24-27·59) and mixed animal replacement origin (P = 0017; OR = 5·19; IC (95%) = 1·35-20·47) were detected as risk factors for BPS positivity to Salmonella spp. This is the first evidence of serovars of Salmonella spp. circulating in BPS from central Chile. Detected serovars have been linked to human and animal clinical outbreaks worldwide and in Chile, highlighting the importance of BPS on the control and dissemination of Salmonella serovars potentially hazardous to public health.

Principais doenças em Anseriformes / Major diseases in Anseriforme

Anseriforme é uma ordem composta por inúmeras espécies de aves aquáticas. No Brasil as principais espécies criadas são patos e gansos em sua maioria criadas em sistemas de subsistência, poucos são os criatórios industriais. Mesmo com a produção informal o comércio de aves vivas, ovos e carne é pratica comum em todo território nacional, mas não se tem conhecimento da prevalência de enfermidades em aves aquáticas, podendo trazer risco a saúde pública. Anseriformes podem apresentar tanto doença clínica quanto inaparente, de etiologia viral, bacteriana, parasitária e micótica. Estudos sobre quadro clínico, aspectos epidemiológicos, achados anatomopatológicos são necessários para criar métodos diagnósticos eficazes para identificar aves doentes. Doenças virais são as mais relatadas e de maior impacto econômico em criações dessa ordem de aves, mais as enfermidades bacterianas, assim como micóticas e parasitárias também podem ocorrer. Por esse motivo, esse estudo tem como objetivo revisar as principais enfermidades presentes em aves aquáticas.

Anseriforme is an order composed of numerous species of waterfowl. In Brazil the mainspecies created are ducks and geese, mostly in sustenance systems, there are few industrial farms.Even with informal production trade in live poultry, eggs and meat is common practice throughoutthe country, but it isn’t aware of the prevalence of disease in waterfowl, may pose a risk to publichealth. Anseriformes can present both clinical disease and unapparent, viral diseases, bacterial,parasitic and fungal. Studies on clinical, epidemiological, pathological findings are needed to createeffective methods diagnostics to identify sick birds. Viral diseases are the most reported and greatereconomic impact in that order poultry farms, most bacterial diseases, as well as fungal and parasiticmay also occur. Therefore, this study aims to review the main diseases present in waterfowl.

Principais doenças em Anseriformes / Major diseases in Anseriforme

Anseriforme é uma ordem composta por inúmeras espécies de aves aquáticas. No Brasil as principais espécies criadas são patos e gansos em sua maioria criadas em sistemas de subsistência, poucos são os criatórios industriais. Mesmo com a produção informal o comércio de aves vivas, ovos e carne é pratica comum em todo território nacional, mas não se tem conhecimento da prevalência de enfermidades em aves aquáticas, podendo trazer risco a saúde pública. Anseriformes podem apresentar tanto doença clínica quanto inaparente, de etiologia viral, bacteriana, parasitária e micótica. Estudos sobre quadro clínico, aspectos epidemiológicos, achados anatomopatológicos são necessários para criar métodos diagnósticos eficazes para identificar aves doentes. Doenças virais são as mais relatadas e de maior impacto econômico em criações dessa ordem de aves, mais as enfermidades bacterianas, assim como micóticas e parasitárias também podem ocorrer. Por esse motivo, esse estudo tem como objetivo revisar as principais enfermidades presentes em aves aquáticas.(AU)

Anseriforme is an order composed of numerous species of waterfowl. In Brazil the mainspecies created are ducks and geese, mostly in sustenance systems, there are few industrial farms.Even with informal production trade in live poultry, eggs and meat is common practice throughoutthe country, but it isnt aware of the prevalence of disease in waterfowl, may pose a risk to publichealth. Anseriformes can present both clinical disease and unapparent, viral diseases, bacterial,parasitic and fungal. Studies on clinical, epidemiological, pathological findings are needed to createeffective methods diagnostics to identify sick birds. Viral diseases are the most reported and greatereconomic impact in that order poultry farms, most bacterial diseases, as well as fungal and parasiticmay also occur. Therefore, this study aims to review the main diseases present in waterfowl.(AU)

Detection and Molecular Identification of Sarcocystis rileyi (Apicomplexa: Sarcocystidae) From a Northern Shoveler (Anas clypeata) in Mexico.

We detected macroscopic Sarcocystis cysts in a Northern Shoveler ( Anas clypeata ) in the Lerma Marshes, State of Mexico, Mexico in February 2014. The 5.0×2.0-mm macrocysts in the breast muscle of the duck were ovoid and yellow. Using an optical microscope, we saw parasitic forms of a Sarcocystis sp. among muscular fibers; the cysts measured 3.5×1.1 mm. The external wall had a smooth surface and the internal wall had a spongy texture. We identified the macrocysts as Sarcocystis rileyi according to sequences of the 18S rRNA gene, 28S rRNA gene, and ITS-1 region. Sarcocystosis should be considered in similar assessments in wild waterfowl in Mexico. Awareness of S. rileyi among anatids in the Lerma Marshes will contribute to more-effective conservation and management actions.

Intestinal lactic acid bacteria from Muscovy duck as potential probiotics that alter adhesion factor gene expression.

The purpose of this study was to assess the suitability of lactic acid bacteria (LABs) isolated from Muscovy duck as a potential probiotic. Isolates were identified by targeted polymerase chain reaction and assessed in vitro for probiotic characteristics such as autoaggregation; surface-charge; hydrophobicity; tolerance to acidic pH, bile salts and protease; and expression of genes involved in Caco-2 cell adhesion. The LAB isolates exhibited strong resistance to high bile concentration and acidic pH, produced lactic acid, and bacteriostatic (P < 0.05) were identified as bacilli compared with LAB isolates of cocci. Additionally, the LAB isolates showed high sensitivity to penicillin and tetracycline antibiotics, while they were resistant to ofloxacin, Macrodantin, and cotrimoxazole. The level of F-actin mRNA increased in the groups treated with CM3, Salmonella enterica, and CM3 + S. enterica (P < 0.0001, P < 0.05 and P < 0.05 ). The level of cell adhesion molecule (CAM) and E-cadherin (E-cad) mRNA expression was significantly lower in the treatment group (P < 0.05 for both) than in the control. The F-actin, CAM, and E-cad mRNA levels were significantly lower in the S. enterica and CM3 + S. enterica groups (P < 0.01) than in the CM3 group. Among these, RNA levels were higher in the CM3 + S. enterica than S. enterica group. These results indicate that the natural duck gut microflora is an excellent source for probiotic bacteria and can facilitate the establishment of criteria to select probiotic strains for the prevention of diarrhea.

Zoonotic species of the genus Arcobacter in poultry from different regions of Costa Rica.

In recent years, emerging pathogens have received special attention due to their consequences for public health. Given that Arcobacter has been isolated in Costa Rica from commercial meat poultry samples, the aim of this research was to determine its isolation frequency from laying hens, broilers, ducks, and geese and to compare two types of samples, namely, cloacal swabs and stool collection. Arcobacter was isolated from 22 (11%) of the 200 samples examined. Fifteen (55%), eight (30%), and four (15%) of the isolated strains were identified as A. butzleri, A. cryareophilus, and Arcobacter spp., respectively. Also, there is a statistically significant difference among the isolation frequencies of Arcobacter for the types of samples evaluated, yielding more isolates from stool samples than from cloacal swab collection. This work describes the distribution of Arcobacter in farm animals as potential sources for its spread from animal-derived products.

Effect of Bacillus subtilis natto on growth performance in Muscovy ducks

The aim of the present study was to determine whether dietary Bacillus subtilis natto could affect growth performance of Muscovy ducks. A total of 120 hundred Muscovy ducks at the age of 1 day were randomly assigned to four groups (30 Muscovy ducks/group), and fed with diets supplemented with 0% (control group), 0.1%, 0.2%, and 0.4% Bacillus subtilis natto, respectively during the 6-week feeding period. Weight gain, feed intake and feed conversion efficiency of Muscovy ducks were significantly improved by the dietary addition of Bacillus subtilis natto, and the results were more significant in 0.4% dietary Bacillus subtilis natto treatment group; Also, Bacillus subtilis natto reduced Escherichia coli and Salmonella colonies, and increased lactobacilli population in the ileum and the cecum. Biochemical parameters, including total protein, GOT (glutamic oxaloacetic transaminase), GPT (glutamic pyruvic transaminase), AKP (alkaline phosphatase), triiodothyronine (T3) and tetraiodothyronine (T4) contents (pBacillus subtilis natto was added to the diets (p 0.05), and improved duodenum and immune functions. However, the results above were not significantly different between birds fed 0.1% Bacillus subtilis natto supplemented diets and the control group (p>0.05). The results of the present study indicate that diets with 0.4% Bacillus subtilis natto improved the growth performance of Muscovy ducks by increasing the absorption of protein, simulating hormone secretion, suppressing harmful microflora, and improving the duodenal structure and immune functions of Muscovy ducks. It is suggested that Bacillus subtilis natto is a potential candidate to be used use as a probiotic to improve the growth performance of Muscovy ducks.(AU)

Effect of Bacillus subtilis natto on growth performance in Muscovy ducks

The aim of the present study was to determine whether dietary Bacillus subtilis natto could affect growth performance of Muscovy ducks. A total of 120 hundred Muscovy ducks at the age of 1 day were randomly assigned to four groups (30 Muscovy ducks/group), and fed with diets supplemented with 0% (control group), 0.1%, 0.2%, and 0.4% Bacillus subtilis natto, respectively during the 6-week feeding period. Weight gain, feed intake and feed conversion efficiency of Muscovy ducks were significantly improved by the dietary addition of Bacillus subtilis natto, and the results were more significant in 0.4% dietary Bacillus subtilis natto treatment group; Also, Bacillus subtilis natto reduced Escherichia coli and Salmonella colonies, and increased lactobacilli population in the ileum and the cecum. Biochemical parameters, including total protein, GOT (glutamic oxaloacetic transaminase), GPT (glutamic pyruvic transaminase), AKP (alkaline phosphatase), triiodothyronine (T3) and tetraiodothyronine (T4) contents (pBacillus subtilis natto was added to the diets (p 0.05), and improved duodenum and immune functions. However, the results above were not significantly different between birds fed 0.1% Bacillus subtilis natto supplemented diets and the control group (p>0.05). The results of the present study indicate that diets with 0.4% Bacillus subtilis natto improved the growth performance of Muscovy ducks by increasing the absorption of protein, simulating hormone secretion, suppressing harmful microflora, and improving the duodenal structure and immune functions of Muscovy ducks. It is suggested that Bacillus subtilis natto is a potential candidate to be used use as a probiotic to improve the growth performance of Muscovy ducks.

Comparison of polymerase chain reaction and bacterial culture for Salmonella detection in the Muscovy duck in Trinidad and Tobago.

OBJECTIVES: The purpose of this study was to investigate the presence and serovar identity of Salmonella, at the national level, in farmed Muscovy ducks (Cairina moschata) in Trinidad and Tobago, and to compare the relative benefits of bacterial culture to those of polymerase chain reaction (PCR) for use in the routine detection and surveillance of Salmonella in these ducks. METHODS: From March-September 2003, 110 fecal samples were collected from 82 farms across the islands of Trinidad and Tobago. Salmonella was isolated from fresh and frozen samples and the serotype of each was determined through bacterial culture. An in-house, nested PCR that detects all pathogenic Salmonella species was utilized in analyzing the samples. RESULTS: Five samples were positive for Salmonella by bacterial culture, whereas 44 were positive by the nested PCR. Serovars isolated were Kiambu, Orion, Uganda, and two isolates from Group E1 whose H antigens could not be fully characterized. Of the samples, 87 (79%) gave equivalent PCR results for both enrichment broths-28 were positive for both and 59 were negative for both). However, 16 samples were positive for one broth, but not for the other, with the majority (14 of the 16) resulting positive for Selenite broth. PCR results for seven samples were inconclusive due to ambiguous band size or multiple bands near the expected band size. CONCLUSIONS: In Trinidad and Tobago, the Muscovy duck does not appear to be a significant source of S. typhimurium or S. enteritidis, but it does harbor other Salmonella species. In-house, nested PCR represents a simple, relatively inexpensive and potentially more sensitive method than bacterial culture for the routine surveillance of pathogenic Salmonella in the Muscovy duck.

Comparison of polymerase chain reaction and bacterial culture for Salmonella detection in the Muscovy duck in Trinidad and Tobago / Comparación de la reacción en cadena de la polimerasa y el cultivo bacteriano como métodos de detección de Salmonella en patos criollos en Trinidad y Tobago

OBJECTIVES: The purpose of this study was to investigate the presence and serovar identity of Salmonella, at the national level, in farmed Muscovy ducks (Cairina moschata) in Trinidad and Tobago, and to compare the relative benefits of bacterial culture to those of polymerase chain reaction (PCR) for use in the routine detection and surveillance of Salmonella in these ducks. METHODS: From March-September 2003, 110 fecal samples were collected from 82 farms across the islands of Trinidad and Tobago. Salmonella was isolated from fresh and frozen samples and the serotype of each was determined through bacterial culture. An in-house, nested PCR that detects all pathogenic Salmonella species was utilized in analyzing the samples. RESULTS: Five samples were positive for Salmonella by bacterial culture, whereas 44 were positive by the nested PCR. Serovars isolated were Kiambu, Orion, Uganda, and two isolates from Group E1 whose H antigens could not be fully characterized. Of the samples, 87 (79 percent) gave equivalent PCR results for both enrichment broths-28 were positive for both and 59 were negative for both). However, 16 samples were positive for one broth, but not for the other, with the majority (14 of the 16) resulting positive for Selenite broth. PCR results for seven samples were inconclusive due to ambiguous band size or multiple bands near the expected band size. CONCLUSIONS: In Trinidad and Tobago, the Muscovy duck does not appear to be a significant source of S. typhimurium or S. enteritidis, but it does harbor other Salmonella species. In-house, nested PCR represents a simple, relatively inexpensive and potentially more sensitive method than bacterial culture for the routine surveillance of pathogenic Salmonella in the Muscovy duck.

OBJETIVOS: Investigar la presencia de Salmonella en patos criollos (Cairina moschata) criados en Trinidad y Tobago e identificar los serotipos circulantes en el país, así como comparar los beneficios relativos del cultivo bacteriano con respecto a la reacción en cadena de la polimerasa (RCP) en la detección y la vigilancia cotidianas de la Salmonella en estos patos. MÉTODOS: Entre marzo y septiembre de 2003 se tomaron 110 muestras de heces fecales de 82 granjas distribuidas por las islas de Trinidad y Tobago. Se aisló Salmonella de muestras frescas y congeladas y se determinaron los serotipos mediante el cultivo bacteriano. Se utilizó un sistema autóctono de RCP anidada que detecta todas las especies patógenas de Salmonella en las muestras. RESULTADOS: Cinco muestras resultaron positivas para Salmonella mediante el cultivo bacteriano, mientras que 44 fueron positivas mediante la RCP anidada. Se asilaron los serotipos Kiambu, Orion, Uganda y dos aislamientos del grupo E1, cuyos antígenos H no se pudieron caracterizar totalmente. Hubo coincidencia en 87 (79 por ciento) de las muestras analizadas por RCP en ambos caldos de enriquecimiento (28 positivas y 59 negativas). Sin embargo, 16 muestras positivas en un caldo resultaron negativas en el otro; la mayoría de ellas (14 de 16) resultaron positivas en caldo selenito. Siete muestras resultaron indefinidas mediante la RCP debido a tallas ambiguas de las bandas o a múltiples bandas cerca de la talla esperada. CONCLUSIONES: El pato criollo no parece ser una fuente importante de infección por S. typhimurium y S. enteritidis en Trinidad y Tobago, aunque hospeda otras especies de Salmonella. El sistema autóctono de RCP anidada constituye un método simple, relativamente económico y posiblemente más sensible que el cultivo bacteriano en la vigilancia cotidiana de especies patógenas de Salmonella en el pato criollo.

Prevalence of thermotolerant species of Campylobacter and their biotypes in children and domestic birds and dogs in southern Chile.

The prevalence of thermotolerant Campylobacter in diarrhoeic and healthy children as well as in dogs, hens, ducks and pigeons was determined in Southern Chile. Campylobacter were found in 34.5% of the faecal samples examined. The isolation rate of Campylobacter in diarrhoeic and healthy children was 16.3% and 6.4% respectively. Despite C. jejuni was always more frequent than C. coli, the latter was isolated with a high frequency (29%) from patients with diarrhoea. C. jejuni and C. coli biotypes I and II were found in healthy and diarrhoeic children and were predominant in all the animals species studied. This may point out towards the possible origin of strains infecting children.

Cloacal flora isolated from wild black-bellied whistling ducks (Dendrocygna autumnalis) in Laguna La Nacha, Mexico.

Cloacal swabs from 110 adult black-bellied whistling ducks trapped at Laguna La Nacha, Tamaulipas, Mexico, were cultured to determine the prevalence of normal and potentially pathogenic bacteria. Twenty-five gram-negative enterobacteria and four gram-positive cocci were isolated. The most common isolates included Escherichia coli (54%), Staphylococcus spp. (29%), Streptococcus spp. (22%), Aeromonas hydrophila (15%) Enterobacter cloacae (14%), and Micrococcus sp. (14%). The implications of whistling ducks as possible reservoirs of pathogenic bacteria are discussed.