Marjô Cadó Bessa

Prevalência de Salmonella sp em suínos abatidos em frígoríficos do Rio Grande do Sul

Este estudo foi realizado com o objetivo de determinar a prevalencia de Salmonella sp em suinos abatidos em frigorificos sob inspecao federal no Rio Grande do Sul. Amostras de fezes e linfonodos foram coletadas em tres diferentes frigorificos no Estado. A partir da analise microbiologica das amostras de 300 animais, encontrou-se uma prevalencia de Salmonella sp de 55,66%, com 17,6% de isolamentos a partir dos linfonodos, 18,3% das fezes e 19,6% em ambos os materiais. Foram identificados 26 sorovares diferentes em 226 isolados de Salmonella sp. Os sorovares mais prevalentes foram: Typhimurium (24,3%), Agona (19,9%), Derby (13,2%) e Bredeney (12%). Estes resultados indicam a necessidade de implementar programas de controle com o objetivo de diminuir a prevalencia de animais portadores ao abate.

Salmonella spp. in raw broiler parts: occurrence, antimicrobial resistance profile and phage typing of the Salmonella Enteritidis isolates

The present study was carried out to evaluate the occurrence of Salmonellae in raw broiler parts and to determine the antimicrobial resistance profile of the isolated strains. Twenty-four (39.3%) broiler parts samples were positive for Salmonella and twenty-five Salmonella strains were isolated, since two different serovars were detected in one single positive sample. Salmonella Enteritidis was the most prevalent serovar. Among Salmonella Enteritidis isolates, 95.2% belonged to Phage Type 4 (PT4) (20/21) and 4.8% to PT7 (1/21). Twenty-two (88%) strains of Salmonella were resistant to at least one antimicrobial agent, generating eight different resistance patterns. The S. Typhimurium (n: 1) and S. Hadar (n: 3) isolates presented multiple resistance. Three S. Enteritidis isolates were susceptible to all antimicrobials tested, two were resistant only to tetracycline. The high prevalence of Salmonella in the broiler parts strenghtens the importance of the use of good manufacturing practices (GMP), and HACCP. The results also emphasize the need for the responsible use of antimicrobials in animal production.

Effects of prebiotics and probiotics on the colonization and immune response of broiler chickens challenged with Salmonella Enteritidis

The present study aimed at evaluating the effect of the prebiotic Bio Mos™ (2 kg/ton up to 10 days; 1 kg/ton from 10 to 21 days; and 0.5 kg/ ton from 21 days to slaughter), of the probiotic Lac XCL 5x™ (by spraymixing), of a combination of the two supplements (prebiotic + probiotic), and of one growth promoter antimicrobial agent (Avilamycin at 15 ppm). Birds were orally challenged with inoculated Salmonella Enteritidis (SE) 10 6 CFU at 3 days of age. Four hundred and eighty male Ross chicks were used. The experiment lasted 28 days, and the analyses were conducted at 15 and 28 days of age. Cecum and liver bacterial colonization of production of anti-SE antibiodies, intestinal micrometry and bird performance were assessed. Neither the prebiotic, nor the probiotic influenced performance or production of anti-SE antibodies in SE-challenged birds. Intestinal micrometry and bird mortality were not influenced by prebiotic or probiotic supplementation, or by the antimicrobial agent. The use of an antimicrobial agent produced higher SE CFUs in cecum bacterial counts, while prebiotic and probiotic yielded lower counts. The combination prebiotic+probiotic did not produce significantly different results from the individual use of the additives.

Phenotypic and genotypic characterization of Salmonella enteritidis isolates

In order to study the epidemiology of Salmonella Enteritidis outbreaks and determine the source of contamination so that a recurrence can be avoided, detailed characterization is necessary. Thus, the purpose of this study was to verify whether rep-PCR was able to discriminate among Salmonella Enteritidis isolates. Phage typing, detection of virulence genes and antimicrobial resistance testing were also associated to repPCR results. One hundred and two S. Enteritidis isolates from broiler carcasses, food, human, pigs, poultryrelated samples, and nine isolates from other countries were genotypically typed by REP-PCR, ERIC-PCR and BOX-PCR, collectively called rep-PCR. Phage typing, detection of virulence genes and antimicrobial resistance testing were also performed. Only three fingerprinting profiles were obtained with each rep-PCR method, with the majority of isolates belonging to the same profile. No relationship was observed between genotypic profile and year, place of isolation or source of infection. However, the less frequent rep-PCR profiles showed single antimicrobial resistance patterns. Although few strains isolated from swine were analyzed, different antimicrobial resistance patterns were observed. Furthermore, phage type 4 was not found in swine isolates. rep-PCR showed a lower discriminatory power as compared with antimicrobial resistance and phage typing, but the combination of genotypic and phenotypic methods was more discriminatory than any method alone, resulting in 48 different types.

Salmonella enterica: isolamento e soroprevalência em suínos abatidos no Rio Grande do Sul

The prevalence of Salmonella in slaughtered swines was evaluated and the results of serology and Salmonella isolation were compared to determine the most important stage of the infection (on-farm or transport and pre-slaughter) in relation to the number of carrier animals found at slaughter. Forty herds from three different swine raisers of the southern region of Brazil were sampled at slaughter. Blood and mesenteric lymph nodes were collected from 20 swines of each herd. Serum samples were submitted to ELISA including somatic antigens of S. Typhimurium. Salmonella was isolated from 62.5% to 85.0% of the animals, while seroprevalence varied from 73.8% to 83.2% in the three swine raisers. Serovar Agona, Typhimurium, and Panama were the most prevalent among the Salmonella isolates. Isolation and serological results demonstrated that Salmonella infection occurred during the on-farm stage, since a high seroprevalence was detected at slaughter. It was concluded that a Salmonella control program in southern Brazil must be started with the implementation of intervention measures at farm level.

Sensibilidade e resistência de amostras de Salmonella Typhimurium isoladas de suínos abatidos no Rio Grande do Sul/Brasil frente aos desinfetantes químicos quaternário de amônio e iodofor

For prevention of infectious diseases common to man and animals such as salmonellosis, the successful use of disinfectants is of great importance. However, intrinsic or acquired resistance presented by microorganism against these compounds may constitute a limiting aspect in disinfections protocols. This study was aimed at monitoring the sensitivity of 96 Salmonella Typhimurium strains isolated from slaughter pigs in the state of Rio Grande do Sul, Brazil. The isolates were tested against quaternary ammonium and iodophor, which represent two commercial disinfectants commonly used in animal production. The tested disinfectants were used in the concentration recommended by the fabricant and in a subconcentration in order to simulate a possible field situation. Dilution suspension tests were conducted, observing the inactivation of each S.Typhimurium isolate after 5, 15, 30 and 60 minutes of contact with each compound. All tested isolates were inactivated by the quaternary ammonium compound in both concentrations. Four isolates revealed resistant to iodophor in the recommended concentration and 59 isolates when a sub-concentration was tested. The testing of resistance against disinfectants in microorganisms present on farm and in food processing plants might be an important step on monitoring the effectiveness of adopted disinfections protocols.

Qualidade sanitária de embutidos coletados no mercado público central de Porto Alegre-RS

Noventa e tres amostras de embutidos coletados no Mercado Publico Central de Porto Alegre foram analisadas quanto a presenca de Salmonella sp. e a contagem de coliformes fecais. Todos as amostras apresentaram ausencia de Salmonella sp., enquanto, em relacao aos coliformes fecais, constatou-se que quatorze amostras de embutidos frescais encontravam-se acima do padrao estabelecido pela portaria n° 451, em vigor no momento da coleta. Entretanto, se fossem considerados os parâmetros estabelecidos na Resolucao n° 12, em vigor atualmente, apenas cinco amostras seriam consideradas fora de padrao. A maioria das amostras com contagens de coliformes fecais acima de 5x102/g estava armazenadas acima da temperatura adequada no momento da coleta.

Quantificação de coliformes, Staphylococcus aureus e mesófilos presentes em diferentes etapas da produção de queijo frescal de leite de cabra em laticínios

The aim of this study was to evaluate the hygienic conditions throughout the manufacture process of a goat unripened cheese, using the enumeration of coliforms, S. aureus and aerobic mesofilic bacteria as indicators. The production of three different lots of cheese was followed, being collected samples throughout the processing steps. Furthermore, samples of cheese belonging to the same sampled lot were collected in the shelf of a commercial establishment throughout the shelf life period. Swabs were streaked onto blood agar plates; water samples were submitted to colimetric assays; all other samples were submitted to coliform, S. aureus and aerobic mesofilic bacteria enumeration using routine protocols. It was observed a great decreasing of bacterial counts in the raw milk during the pasteurization process. In spite of that, the transfer of the pasteurized milk to the coagulation tank by an equipment, which was previously in contact with the raw milk and was inadequately disinfected, resulted in the recontamination of the pasteurized milk. The packed cheese had bacterial counts according to the standards imposed by the Brazilian food regulatory agency. However, the high aerobic mesofilic bacteria counts suggest that the good manufactures practices have to be improved in order to guarantee the hygienic quality and an extender shelf life for the cheese.