Salmonella serovars and antimicrobial resistance profiles in beef cattle, slaughterhouse personnel and slaughterhouse environment in ethiopia.

The present study was undertaken to determine the occurrence, distribution and antimicrobial resistance profiles of Salmonella serovars in slaughter beef cattle, slaughterhouse environment and personnel engaged in flaying and evisceration during slaughtering process. A total of 800 samples (each sample type, n = 100) consisting of swabs from hides, slaughterhouse personnel hands at flaying and evisceration, rumen and caecal contents, mesenteric lymph nodes, carcasses and holding pens were collected. Of the total 100 beef cattle examined, 14% were Salmonella positive in caecal content and/or mesenteric lymph nodes. Of the various samples analysed, Salmonella was detected in 31% of hides, 19% of rumen contents, 8% of mesenteric lymph nodes, 6% of caecal contents, 2% of carcass swabs, 9% of palm swabs taken from the hands of personnel in the slaughterhouse during flaying (7%) and evisceration (2%), and in 12% of holding pen swabs. The Salmonella isolates (n = 87) belonged to eight different serovars of which S. Anatum (n = 54) and S. Newport (19) were the major serovars and both serovars were detected in all sample sources except in carcass swabs. Eighteen of the 87 (20.7%) Salmonella serovars consisting of Newport (n = 14), Anatum (n = 3) and Eastbourne (n = 1) were resistant to one or more antimicrobials. Among the antimicrobial resistant Salmonella serovars, S. Newport was multidrug resistant (15.6%) and exhibited resistance to streptomycin, sulphisoxazole and tetracycline.

Comparison of bacterial culture and real-time PCR for the detection of Salmonella in grow-finish pigs in Western Canada using a Bayesian approach.

The study objective was to evaluate the accuracy of a real-time polymerase chain reaction (RT-PCR) and a culture protocol used to detect Salmonella in the faeces of grow-finish pigs using a Bayesian approach. The RT-PCR was invA-gene-based assay, while the culture protocol included pre-enrichment in buffered peptone water, selective enrichment in tetrathionate and Rappaport-Vassiliadis broths, and isolation on semi-solid (modified semi-solid RV) or solid (XLT4, Rambach) agar plates. Bayesian analysis was performed using a two-test, two-population model with dependence between culture and RT-PCR and compared to a second model with conditional independence between these two tests. Two hundred and ninety three individual faecal and 294 pooled pen samples from grow-finish pig collected from 10 farms were tested and results were divided into two groups according to herd size (five herds <250 sows, five herds with >400 sows). In the dependence model, RT-PCR sensitivity (Se) and specificity (Sp) were estimated to be 90% (95% probability interval 74, 97) and 99% (98, 99), respectively. Culture Se was 92% (75, 99), while culture Sp was considered 100% as all culture-positive samples were confirmed by serotyping. In the conditional independence model, RT-PCR Se and Sp, and culture Se, were 96% (93, 98), 99% (98, 100) and 97% (94, 100), respectively. The dependence model resulted in posterior estimates of Se that were lower and with broader probability intervals than the independence model, indicating that when RT-PCR and culture are evaluated relative to each other, the correlation between these tests is an important source of bias and should be adjusted for during analysis. The RT-PCR evaluated in this study performed almost comparably to culture; given the cost savings associated with using this test and more timely results, the RT-PCR may be a useful alternative to culture for screening large numbers of samples, particularly when Salmonella prevalence is low.

The characterization of Salmonella serovars isolated from apparently healthy slaughtered pigs at Addis Ababa abattoir, Ethiopia.

We looked for Salmonella in all 278 apparently healthy pigs slaughtered between September 2004 and May 2005 at the only pig-slaughtering slaughterhouse in Addis Ababa, Ethiopia. We used standard methods and tested caecal contents, mesenteric lymph nodes, and carcass swabs from each pig (missing only one carcass swab). Of the 278 pigs, 120 (43%) were positive; of the 833 samples 173 (21%) were positive. Thirty-three percent of the isolates were multi-resistant (including 46/48 isolates of S. Hadar, but none of the 39 isolates of S. Eastbourne or of the 37 of S. Saintpaul). Resistance to streptomycin (32.4%), tetracycline (31.8%) and nitrofurantoin (27.2%) was relatively high. The most common pattern of MDR observed was to nitrofurantoin, streptomycin and tetracycline (Resistance type NitStrTet). Our results indicate that salmonellae are prevalent in pigs slaughtered at Addis Ababa abattoir and a large proportion of the isolates were multi-drug resistant.

Multidrug resistance and distribution of Salmonella serovars in slaughtered pigs.

The present study was undertaken to estimate the occurrence and distribution of multidrug resistance (MDR) among Salmonella serovars isolated from slaughtered pigs at Debre Zeit, Ethiopia. A total of 501 different samples were examined of which 42 (41.6%) of 101 mesenteric lymph nodes, 22 (21.8%) of 101 tongues, 17 (16.8%) of 101 caecal contents, 11 (11.1%) of 99 livers and two (2%) of 99 muscle (diaphragm and abdomen) samples were Salmonella positive. Of the 94 Salmonella isolates representing 15 different serovars, 69 (73.4%) were multidrug resistant (resistance to two or more antimicrobials). Among the Salmonella serovars a high level of MDR was observed in S. Hadar, S. Kentucky, S. Blockley and S. Enteritidis mainly to tetracycline (88.6%), streptomycin (82.9%), nitrofurantoin (74.3%), nalidixic acid and ciprofloxacin (42.9% each), sulfisoxazole (21.1%) and spectinomycin (20%). The pattern of MDR varied from two to eight antimicrobials among the resistant Salmonella serovars. The common profiles of resistance among the MDR serovars were the combined resistance to nitrofurantoin, streptomycin and tetracycline (R type NitStrTet, 51.4%), ciprofloxacin, nalidixic acid and nitrofurantoin (R type CipNalNit, 10%), ciprofloxacin, nalidixic acid, spectinomycin, streptomycin, sulfisoxazole and tetracycline (R type CipNalSptStrSulTet, 14.3%) and to ciprofloxacin, kanamycin, nalidixic acid, neomycin, nitrofurantoin, streptomycin and tetracycline (R type CipKanNalNeoNitStrTet, 10%). Results of the present study indicate the widespread occurrence and distribution of MDR Salmonella serovars in slaughtered pigs which could be a potential source of human MDR Salmonella infections.

Occurrence and antimicrobial resistance of Salmonella serovars in apparently healthy slaughtered sheep and goats of central Ethiopia.

The present study was undertaken to determine the occurrence, distribution and antimicrobial resistance pattern of Salmonella serovars in apparently healthy slaughtered sheep and goats in central Ethiopia. A total 1224 samples consisting of faeces, mesenteric lymph nodes, liver, spleen, and abdominal and diaphragmatic muscle samples were collected from 104 sheep and 100 goats. Salmonella was isolated from 12 of 104 (11.5%) sheep and 3 of 100 (3%) goats. Of the total 624 and 600 samples examined from sheep and goats, 18 (2.9%) and 4 (0.7%), respectively, were Salmonella positive. The 22 Salmonella isolates belonged to 9 different serovars. The common serovars isolated were S. typhimurium, followed by S. heidelberg, S. reading, S. give, and S. poona. Seven of the 22 isolates (31.8%) were multidrug-resistant to various antimicrobials.

Prevalence and antimicrobial resistance pattern of Salmonella isolates from apparently healthy slaughtered cattle in Ethiopia.

The prevalence and antimicrobial resistance pattern of Salmonella isolates was determined from apparently healthy slaughtered cattle at Debre Zeit (Ethiopia). A total of 323 cattle were examined for the presence of Salmonella in faeces, mesenteric lymph nodes, abdominal and diaphragmatic muscles. Salmonellae were cultured from 23 (7.1%) of the animals. Salmonellae were isolated from 2 (3.1%) and 3 (4.5%) of 65 pooled faecal and mesenteric lymph node samples, respectively. Nine (2.8%) abdominal muscle and 10 (3.1%) diaphragmatic muscle samples (n = 323 of each) were contaminated by Salmonella. About 60% of the serovars identified in the abdominal and diaphragmatic muscles were also detected from faeces and mesenteric lymph node samples. The five different serovars isolated were Salmonella mishmarhaemek (48%) S. typhimurium (20%). S. enteritidis (12%), S. guildford (12%) and S. dublin (48%). The antimicrobial resistance profiles of 25 of the Salmonella isolates with 17 antimicrobials showed that 52%, (13/25) of them were resistant to three or more antimicrobials. Both strains of Salmonella (S. mishmarhaemek and S. typhimurium) showed multiple resistance to ampicillin, sulfamethoxazole and ticarcillin.

Characterization of Salmonella associated with pig ear dog treats in Canada.

In the summer of 1999, the incidence of Salmonella enterica serotype Infantis infections in Alberta rose dramatically. Subsequent laboratory and epidemiological investigations established that an outbreak of human disease caused by this organism was occurring across Canada and was associated with pet treats for dogs produced from processed pig ears. Laboratory investigations using phage typing and pulsed-field gel electrophoresis (PFGE) established that isolates of Salmonella serotype Infantis from pig ear pet treats and humans exposed to pig ear pet treats comprised a well-defined subset of all isolates analyzed. Of the 53 subtypes of Salmonella serotype Infantis obtained around the time of the outbreak as defined by PFGE and phage typing, only 6 subtypes were associated with both human infection and isolation from pig ears. Together with information from epidemiological studies, these investigations established pig ear pet treats as the cause of the Salmonella serotype Infantis outbreak. The results are consistent with a model in which contaminated pig ear pet treats constitute a long-term, continuing vehicle for infection of the human population rather than causing temporally delimited point-source outbreaks. During the course of this outbreak, several other Salmonella serotypes were also isolated from pet treats, suggesting these products may be an important source of enteric infection in both humans and dogs. Though isolates of Salmonella serotypes other than Salmonella serotype Infantis from pet treats were also subjected to PFGE and phage typing, no link with human disease could be definitively established, and the contribution of pig ear pet treats to human disease remains unclear. Elimination of bacterial contamination from pet treats is required to reduce the risk of infection from these products.

Neurophysiological assessment of sensory gating in psychiatric inpatients: comparison between schizophrenia and other diagnoses.

Gating of auditory sensory responsiveness was examined in 75 psychiatric inpatients using a conditioning-testing paradigm with the P50 wave of the auditory evoked response, in which pairs of stimuli are presented to the subject. In previous studies, most schizophrenics did not decrement the second response to the extent seen in normals. Acutely ill patients, who were representative of patients admitted to a public university teaching service and a proprietary hospital, were used to examine the extent to which diminished sensory gating is found in diagnoses other than schizophrenia. About half of these patients showed diminished sensory gating that correlated with measures of severity of illness. The data, taken together with that from other studies using this paradigm, suggest that diminished sensory gating, like several other psychophysiological abnormalities, is a trait deficit in schizophrenia, but a state deficit in many other mental illnesses.