Salmonella Typhimurium CARRIAGE at slaughter AFTER an enterocolitis outbreak in a swine herd

The aim of this study was to estimate the prevalence of slaughter pigs carrying Salmonella Typhimurium after a entericolitis outbreak in a commercial pig farm. A cross-sectional study was done during the slaughter of a batch of 86 animals. Mesenteric lymph nodes from 43 pigs were collected and pre-enriched in buffered peptone water (1:10) overnight at 37∞C Afterwards, aliquots of 1mL and 0.1mL were transferred to selenite-cystine and Rappaport-Vassiliadis broth, respectively. A loopful of each sample was streaked onto XLT4 and brilliant green agar plates, which were incubated at 37∞C for 24 hours. Salmonella was cultured in 23 out of 43 collected samples (53.48%). Salmonella Typhimurim (13 strains) and Salmonella enterica subs. enterica 1,4,5,12:i:- (10 strains) were isolated. These results indicated that the slaughter of pigs from batches previously affected by enteric salmonellosis may represent a high risk for pork contamination, since there is an positive association between infected pigs before slaughter and carcass contamination

Stool processing-methods for Salmonella enterica isolation and PCR detection

The aim of this study was to compare the efficiency of three protocols for bacteriological isolation of Salmonella enterica and detection by PCR in swine feces samples. Pool of feces (n=62) were processed by three different methods. Method 1: samples (10g) were pre-enriched in BPW (1:10) and enriched in Rappaport-Vassiliadis broth (1:100). Method 2: samples (1g) were first enriched in GN-Hajna broth (1:10) and secondly enriched in Muller-Kaufmann tetrathionate broth (1`:10). Method 3: Single step enrichment of feces (1g) in selenite-cystine broth (1:10). PCR was performed using DNA extracted from the last enrichment broth of each bacteriological method. Salmonella enterica was cultured from 13 out of 62 samples (20.9%) and seven different serotypes were isolated. The methods 1, 2 and 3 resulted in 9 (14.5%), 6 (9.6%) and 2 (3.2%) positive samples, respectively. PCR was significantly superior than conventional bacteriology for Salmonella detection only when Rappaport-Vassiliadis was used for DNA-template preparation

Salmonella Typhimurium CARRIAGE at slaughter AFTER an enterocolitis outbreak in a swine herd

The aim of this study was to estimate the prevalence of slaughter pigs carrying Salmonella Typhimurium after a entericolitis outbreak in a commercial pig farm. A cross-sectional study was done during the slaughter of a batch of 86 animals. Mesenteric lymph nodes from 43 pigs were collected and pre-enriched in buffered peptone water (1:10) overnight at 37∞C Afterwards, aliquots of 1mL and 0.1mL were transferred to selenite-cystine and Rappaport-Vassiliadis broth, respectively. A loopful of each sample was streaked onto XLT4 and brilliant green agar plates, which were incubated at 37∞C for 24 hours. Salmonella was cultured in 23 out of 43 collected samples (53.48%). Salmonella Typhimurim (13 strains) and Salmonella enterica subs. enterica 1,4,5,12:i:- (10 strains) were isolated. These results indicated that the slaughter of pigs from batches previously affected by enteric salmonellosis may represent a high risk for pork contamination, since there is an positive association between infected pigs before slaughter and carcass contamination.</p

Antimicrobial resistance of Salmonella serotypes isolated from slaughter-age pigs and environmental samples

The aim of this study was to determine the antimicrobial resistance patterns of Salmonella strains isolated from slaughter-age pigs and environmental samples collected at modern swine raising facilities in Brazil. Seventeen isolates of six serotypes of Salmonella enterica subsp. enterica were isolated out of 1,026 collected samples: Salmonella Typhimurium (1), Salmonella Agona (5), Salmonella Sandiego (5), Salmonella Rissen (1), Salmonella Senftenberg (4), and Salmonella Javiana (1). Resistance patterns were determined to extended-spectrum penicillin (ampicillin), broad-spectrum cephalosporins (cefotaxime and ceftriaxone), aminoglycosides (streptomycin, neomycin, gentamicin, amikacin, and tobramycin), narrow-spectrum quinolone (nalidixic acid), broad-spectrum quinolone (ciprofloxacin and norfloxacin), tetracycline, trimethoprim, and chloramphenicol. Antimicrobial resistance patterns varied among serotypes, but isolates from a single serotype consistently showed the same resistance profile. All isolates were resistant to tetracycline, streptomycin, and nalidixic acid. One isolate, Salmonella Rissen, was also resistant to cefotaxime and tobramycin. All serotypes were susceptible to ceftriaxone, norfloxacin, ciprofloxacin, ampicillin, gentamicin, and chloramphenicol. The high resistance to tetracycline and streptomycin may be linked to their common use as therapeutic drugs on the tested farms. No relation was seen between nalidixic acid and fluoroquinolone resistance

Prevalence of pigs infected by Salmonella typhimurium at slaughter after an enterocolitis outbreak

A cross-sectional study was performed to estimate the prevalence of slaughter pigs infected by Salmonella typhimurium after an enterocolitis outbreak in a commercial pig farm, which was characterised by diarrhoea during the growing phase. Anatomopathological and histopathological findings were suggestive of salmonellosis, which was further confirmed by isolation of S. typhimurium from organs and faeces samples from diseased animals. Ileocolic lymph nodes were aseptically collected from 43 pigs during slaughter procedures. The estimated prevalence of Salmonella-infected pigs was 53.48% [confidence interval (CI): 42.94:64.02%]. This finding demonstrates that the carriage of S. typhimurium at slaughter might be high if pigs originate from a batch previously affected by Salmonella-enterocolitis outbreak at the pre-harvest pork production chain. (c) 2005 Elsevier B.V. All rights reserved

Dunging gutters filled with fresh water in finishing barns had no effect on the prevalence of Salmonella enterica on Brazilian swine farms

Our aim was to assess the importance of dunging gutters filled with water in finishing barns for the prevalence of pigs shedding Salmonella enterica. Some finishing barns in Brazil are provided with a dunging-gutter system which consists of a continuous water flow at the back of solid-floored adjacent pens. Because there is transfer of faecal material between adjacent pens by water in this system and the faecal-oral route of transmission is so important for enteric pathogens, we tested the hypothesis that the presence of this kind of dunging-gutter system in finishing barns affects the prevalence of slaughter-age pigs shedding salmonella organisms in their faeces. The cross-sectional study was conducted on six farms each having barns with and barns without a dunging-gutter system. Breeding, management, nutritional and seasonal factors were similar in both barns on each farm. The two systems did not differ in prevalence of pigs shedding salmonella organisms. Five S. enterica scrotypes were isolated: S. Agona, S. Javiana, S. Rissen, S. Sandiego and S. Senftenberg. (C) 2002 Elsevier B.V. B.V. All rights reserved