Serogroup C1 Research Articles

Improvements to a PCR-Based Serogrouping Scheme for Salmonella enterica from Dairy Farm Samples

Molecular serotyping through the use of PCR is a simple and useful technique for characterizing isolates of Salmonella enterica subsp. enterica belonging to serogroups B, C1, C2, D1, and E1, which are the majority of the isolates associated with human disease outbreaks. However, many of the Salmonella strains currently isolated from dairy farms in the northeastern United States are serovar Cerro, a group K strain not detected by this assay. Primers from a well-known PCR assay for the identification of Salmonella were added to a commonly used serotyping assay so that strains, such as Salmonella Cerro, that do not produce bands in the original assay can be confirmed as belonging to S. enterica subsp. enterica. The modified assay frequently misidentified the serogroup of Salmonella Mbandaka isolates because of failure to amplify the wzxCl amplicon. Therefore, the reverse primer for the wzxCl target was modified based on in silico analysis to provide consistent classification of Salmonella Mbandaka as belonging to serogroup C1. These two modifications to the serogrouping PCR method enhance the utility of the method for characterizing Salmonella isolates.

Prevalence of <i>Salmonella</i> on Sheep Carcasses Slaughtered at Adama Municipal Abattoir, South Eastern Ethiopia

The article has been retracted by the editor.A cross-sectional study was carried to determine the prevalence of Salmonella and Salmonella Serogroups from cattle carcasses slaughtered during November 2011 to April 2012 at Adama municipal abattoir. From a total of 100 sheep carcasses, 300 samples (abomasums, liver and mesenteric lymph nodes) were collected aseptically. Out of 100 animals examined sheep, 14 (14.0%) were Salmonella carriers. Whereas among 300 examined sheep carcass, Salmonella was 17 (5.6%) were found to be positive based on culture methods and different biochemical tests that were employed. The Salmonella was detected in 13 (13%), 7 (7%) of each 100 samples of abomasum’s and mesenteric lymph nodes respectively. Out of the 17 Salmonella isolates, three different Serogroups were identified of which Serogroup B was predominant (63.6%) followed by Serogroup C2 (21.2%) and Serogroup D (15.2%). Results of the present study indicated that Salmonella is a common problem in slaughtered sheep carcasses in Adama municipal abattoir. Therefore, Sources of pathogens in food animals need to be investigated and a further study of pathogens in the food chain is recommended.Keywords: Adama Carcass Ethiopia Prevalence Salmonella Sheep

Time to positivity in blood cultures of adults with nontyphoidal Salmonella bacteremia.

Nontyphoidal Salmonella (NTS) is an important bacterial etiology of diarrheal disease, and it causes invasive diseases in immunocompromised hosts. For bacteremia from some species, blood culture with a rapid time to positivity (TTP) is associated with greater mortality. This study investigated TTP of NTS bacteremia and its relationship to clinical parameters and prognosis. Adult patients with NTS bacteremia who were admitted to a tertiary care facility in northern Taiwan from January 2010 to December 2012 were enrolled. Demographics, clinical and microbiological characteristics, and treatment response were reviewed. The TTP for each patient was retrieved from the automated machine. Sixty-six adult patients (mean age, 66.1 years; range, 27-96 years) with NTS bacteremia were identified by the following serogroup distributions: serogroup B (23.4%), serogroup C1 (1.6%), serogroup C2 (6.3%), and serogroup D (68.8%). The in-hospital mortality, 14-day mortality, and 30-day mortality were 15.2%, 7.6%, and 12.1%, respectively. The TTP ranged 6.5-41.7 hours (median: 11.5 hours). Patients with rapid TTP (less than 10 hours), compared to patients without rapid TTP, were more likely to have liver cirrhosis (31.6% vs. 6.4%, p=0.013), endovascular lesions (21.1% vs. 4.3%, p=0.05), higher bacteremia score, intensive care unit admission (57.9% vs. 25.5%, p=0.021), and septic shock (63.2% vs. 12.8%, p<0.001). There were no significant differences in the in-hospital mortality and 14-day mortality between patients with TTP <10 hours and patients with TTP ≥10 hours. The TTP of blood cultures, interpreted with a cut-off point of <10 hours, in patients with NTS bacteremia may provide useful diagnostic and prognostic information.

Emergence of bla TEM Type Extended-Spectrum β -Lactamase Producing Salmonella spp. in the Urban Area of Bangladesh.

Salmonellosis, an acute invasive enteric infection, is endemic in Bangladesh. We analyzed 128,312 stool samples of diarrheal patients to identify Salmonella spp. during 2005–2013. A total of 2120 (1.7%) Salmonella spp. were isolated and the prevalence of Salmonella spp. decreased significantly over time (2→1%, P < 0.001). Among the typhoidal Salmonella (TS) serogroups, S. Typhi was predominant (404, [65.1%]) followed by S. Paratyphi B (139, [22.4%]) and S. Paratyphi A (78, [12.6%]). Of the nontyphoidal Salmonella (NTS) isolates, the serogroup C1 (560, [37%]) was predominant followed by B (379, [25%]), C2 (203, [14%]), E (127, [9%]), and D (94, [6%]). Most of the resistance was found towards nalidixic acid (40%), ampicillin (36%), cotrimoxazole (20%), chloramphenicol (13%), ciprofloxacin (4%), and ceftriaxone (4%). Interestingly, 32% of the isolates showed reduced susceptibility to Cip. Multiantibiotic resistance (MAR, ≥3 drugs) was more common among TS than NTS strains (P < 0.001). Among the representative ceftriaxone-resistant isolates, bla TEM gene was detected among 88% (7/8) of the strains, whereas only one strain of S. Typhi was positive for both bla TEM and bla CTX-M genes. The study reflects higher prevalence of MAR Salmonella spp. and is the first to report the bla TEM gene mediated ESBL production among Salmonellae in Bangladesh. Emergence of MAR Salmonella spp. in particular ESBL strains should be considered a public health concern.

Prevalence of nontyphoidal Salmonella serogroups and their antimicrobial resistance patterns in a university teaching hospital in Eastern Province of Saudi Arabia.

BackgroundNontyphoidal Salmonella (NTS) species are important food-borne pathogens that cause gastroenteritis and bacteremia, and are responsible for a huge global burden of morbidity and mortality. The aim of this study was to investigate the prevalent serogroups and antibiotic resistance of NTS in our region.MethodsWe reviewed the serogroup distribution and antimicrobial susceptibility patterns of NTS strains obtained from 158 stool specimens of patients with acute diarrheal infection attending the outpatient and inpatient department at a university hospital in the Eastern Province of Saudi Arabia in the period from September, 2008 to April, 2011. A retrospective analysis of the 158 patients with NTS infection was conducted to determine the most prevalent NTS serogroups causing acute gastroenteritis and their antimicrobial susceptibility patterns.ResultsAt this teaching hospital, a total of 17,436 fecal samples were analyzed during the 2008–2011 study period. Of these specimens, 158 tested positive for NTS, giving an overall prevalence of 9.06 per 1,000. Of 158 NTS cases, serogroup D1 (25.3%) was the most prevalent, followed by serogroup B (19.6%), and serogroup C1 (18.9). One third of all NTS serogroup strains tested were resistant to tetracycline. The NTS strains showed resistance to ampicillin (31.3%), amoxicillin/clavulanic acid (29.9%), trimethoprim/sulfamethoxazole (20.9%), and cefotaxime (14.93%).ConclusionThe findings of this study support the concern that use of antibiotics in animal feeds may contribute to acquisition of resistance in food-borne bacteria, such as Salmonella. Our study also concludes that the prevalence of NTS in the Eastern Province of Saudi Arabia is very low compared with other studies worldwide.

Protective immunity to Salmonella enterica is partially serogroup specific

Pre-harvest reduction of Salmonella carriage by swine would benefit both animal health and food quality. While vaccination is an attractive pre-harvest intervention to reduce Salmonella levels in swine, the large number of potential Salmonella enterica serovars found in swine makes it critical that vaccines provide broad serotype efficacy. In order to directly compare the relative efficacy of Salmonella vaccines against serogroup-matched and serogroup-unmatched Salmonella, we vaccinated pigs with two commercially available Salmonella vaccines (either serogroup B or serogroup C1) and challenged with serovar-matched, serogroup-matched or serogroup-unmatched challenge strains. We found that while serogroup-matched vaccines provided relatively better efficacy than unmatched vaccines, serotype-unmatched vaccines also provided significant reduction of Salmonella carriage and shed. In addition, by measuring serogroup specific cell mediated (IFN-γ ELISPOT) and humoral (anti-LPS ELISA) immunity, we found that this serogroup specific efficacy correlates primarily with humoral immunity, while cell mediated immunity was mostly non-serogroup specific. While the practical relevance to pork quality of this serogroup-specific efficacy remains to be demonstrated, the large predominance of serogroup B Salmonella in swine suggests that a serogroup B Salmonella vaccine for swine would be of value to pre-harvest food safety interventions in swine.

국내 노계 운반 전용 차량에서의 살모넬라 오염율 및 차량소독에 따른 오염도 감소 효과

살모넬라는 농장, 부화장, 도계장 그리고 가공장 등, 양계산업 전반에 걸쳐 경제적으로 큰 피해를 가져다 줄 뿐만 아니라, 축산물 소비에 대한 관심이 높아진 현대인들의 건강과 밀접한 연관성을 가지고 있다. 이처럼 축산업 및 현대 식생활에 있어 살모넬라에 대한 관심이 고조되어 있는 상황에서 살모넬라에 대한 다양한 연구가 지속적으로 보고되고 있지만, 실질적으로 농가 및 도계장에 살모넬라 오염을 일으킬 수 있는 노계 운반 전용 차량에 대한 연구가 미흡한 실정이다. 본 연구는 노계 운반을 위해 종계장에 출입하는 전용차량 200대를 선발하여 살모넬라 오염도를 파악하고, 분리된 살모넬라균을 그룹별, 혈청형별, 계절별로 분석하였으며, 노계 운반 차량에서 적용하여 효과적으로 살모넬라를 저해하는 방법인 소독제 분무 방법과 이에 따른 살모넬라 저해율 그리고 소독제 희석 비율에 따른 저해율을 비교하였다. 그 결과, 노계 운반 전용 차량의 50%가 살모넬라균에 오염된 것으로 나타났으며, 그룹별로 C1그룹이 65.8%로 가장 높은 분리율을 나타냈고, 총 25종의 살모넬라균속이 분리, 이 중 C1 그룹에 속하는 S. Infantis가 가장 높은 분리율을 나타냈다. 계절별로 여름철에 채취한 시료에서 73.1%로 가장 높은 분리율을 나타냈다. 포름알데히드(79.8 g/L), 글루탈알데히드(50 g/L), 4급암모늄(60 g/L) 합제 성분이 들어간 소독제를 사용하여 노계 운반 차량에 적용한 결과, 소독 전에 비해 소독 후에 유의적인 살모넬라의 저해 효능을 보였다. 특히, 일반적인 소독제 권고 희석비율인 200:1의 비율에서는 낮은 저해율을 보인 반면 50:1의 희석 비율로 희석한 소독제를 적용한 실험에서는 유의적으로 높은 살모넬라 저해율을 보였다. 본 연구를 통해 노계 운반 전용 차량이 농가 및 도계장의 살모넬라 오염원으로써 충분한 가능성을 제시해 주고 있으므로 노계 도태 차량 또는 도계장으로 실용계를 운반하는 차량에 대하여, 적절하고 철저한 소독을 통해 농가 및 도계장 재오염에 대비할 필요성이 있다고 판단된다. Salmonella is closely related with human health of modern society which has concern increased in livestock goods consumption as well as give economic damage throughout the chicken industry such as farm, hatchery, slaughter house and processing plant. From 2007 to 2011, this study investigated Salmonella prevalence from 200 old hen delivery trucks which deliver old egg-laying hens and broiler breeders in Korea. The prevalence of Salmonella species was 38.0% in old hen delivery truck. Serogroup C1 was the most frequently detected serogroup of Salmonella, followed by the serogroups D1, C2 and B. A total of 25 serotypes were identified and Salmonella infantis was the most frequently isolated serotype. In addition, we applied disinfectant to old hen delivery truck for the reduction of Salmonella contamination. The disinfectant consists of formaldehyde, glutaladehyde and quaternary ammonium compound was applied to the trucks. Salmonella isolation rate was significantly decreased after disinfection from 38.0% to 7.5%. Disinfectant could not effectively reduce Salmonella contamination at a dilution of 1:200 which is recommended by manufacturer, but Salmonella isolation rate was significantly decreased at a dilution of 1:50. Since old hen delivery truck could be a potential vector to carry Salmonella into farms and abattoirs, chicken delivery truck should be disinfected thoroughly and sufficiently to control contamination of farms and abattoirs.

Selective enrichment media bias the types of Salmonella enterica strains isolated from mixed strain cultures and complex enrichment broths.

For foodborne outbreak investigations it can be difficult to isolate the relevant strain from food and/or environmental sources. If the sample is contaminated by more than one strain of the pathogen the relevant strain might be missed. In this study mixed cultures of Salmonella enterica were grown in one set of standard enrichment media to see if culture bias patterns emerged. Nineteen strains representing four serogroups and ten serotypes were compared in four-strain mixtures in Salmonella-only and in cattle fecal culture enrichment backgrounds using Salmonella enrichment media. One or more strain(s) emerged as dominant in each mixture. No serotype was most fit, but strains of serogroups C2 and E were more likely to dominate enrichment culture mixtures than strains of serogroups B or C1. Different versions of Rappaport-Vassiliadis (RV) medium gave different patterns of strain dominance in both Salmonella-only and fecal enrichment culture backgrounds. The fittest strains belonged to serogroups C1, C2, and E, and included strains of S. Infantis, S. Thompson S. Newport, S. 6,8:d:-, and S. Give. Strains of serogroup B, which included serotypes often seen in outbreaks such as S. Typhimurium, S. Saintpaul, and S. Schwarzengrund were less likely to emerge as dominant strains in the mixtures when using standard RV as part of the enrichment. Using a more nutrient-rich version of RV as part of the protocol led to a different pattern of strains emerging, however some were still present in very low numbers in the resulting population. These results indicate that outbreak investigations of food and/or other environmental samples should include multiple enrichment protocols to ensure isolation of target strains of Salmonella.

A Simple Scoring Algorithm Predicting Vascular Infections in Adults With Nontyphoid Salmonella Bacteremia

Nontyphoid Salmonella (NTS) can cause fatal vascular infections. This study aims to establish a predictive scoring algorithm to identify adults aged ≥ 50 years with NTS bacteremia who are at risk for vascular infections. There were 358 adults aged ≥ 50 years with NTS bacteremia at 2 medical centers in southern Taiwan included in this study. Multiple logistic regression was used to identify risk factors for imaging-documented vascular infections. The prediction capability of the proposed scoring algorithm was indicated by a receiver operating characteristic curve and measures of sensitivity and specificity. Sixty patients (16.8%) with vascular infections were noted. The 4 risk factors significantly associated with vascular infections-male sex, hypertension, coronary arterial disease, and serogroup C1 infections-were each assigned +1 point to form the NTS vascular infection (NTSVI) score. In contrast, malignancy and immunosuppressive therapy were each assigned -1 point, owing to their negative associations with vascular infections. Based on the proposed NTSVI scoring, the prevalence of vascular infections in patients with ≤ 0, 1, 2, 3, or 4 points was 2.2% (3 of 138 patients), 10.6% (13 of 123 patients), 39.4% (26 of 66 patients), 55.2% (16 of 29 patients), and 100% (2 of 2 patients), respectively (P< .0001). The scoring algorithm shows an area under the curve of 0.83 (95% confidence interval, .78-.89; P < .0001). A cutoff value of +1 represents a high sensitivity (95.0%) and an acceptable specificity (45.3%). This simple scoring algorithm can be used to identify patients with NTS bacteremia with a high risk of vascular infections. The cost-effectiveness of this algorithm should be further studied.

Emergence of Salmonella enterica Serovar Potsdam as a Major Serovar in Waterfowl Hatcheries and Chicken Eggs

Salmonellosis is a common food-borne illness in humans caused by Salmonella-contaminated poultry and their products. In hatcheries, 110 Salmonella isolates were identified, mostly from first enrichment, and few from delayed enrichment. The Salmonella prevalence in goose and duck hatcheries was higher when measured by four multiplex PCR methods than by traditional culture (73.8% vs. 44.35%, P < 0.05); 97.3% of 110 isolates were Salmonella Potsdam of serogroup C1 and other isolates were Salmonella Montevideo of C1 and Salmonella Albany of C2. Plasmid and pulsed field gel electrophoresis genetic analysis revealed that isolates from duck hatcheries were more diverse than those from goose hatcheries. In Salmonella Potsdam, host species-specific genotypes were observed in geese for genotypes 3, 4, and 5 and in ducks for genotypes 7, 8, and 9, suggesting that Salmonella Potsdam may evolve into goose- and duck-specific isolates. An examination of 1121 eggs found that only Salmonella Potsdam was identified in 1.8% (7/591) of eggs from chickens fed on the ground, not housed in cages, and in egg content (6/7) as well as eggshell membrane (1/7). In conclusion, Salmonella Potsdam may be a major Salmonella infection in waterfowl and chicken eggs.

Differentiation of Salmonella enterica based on PCR detection of selected somatic and flagellar antigens

serogroups C2 (n = 35, 28.7%), B (n = 33, 27.1%), D9 (n = 29, 22.9%), E (n = 21, 17.2%), C1 (n = 2, 64%) and A (n = 2, 1.64%). Eight of the Salmonella strains from serogroup D were positive for Vi antigen. Two multiplex PCRs were optimized for detection of H1 antigens (Ha, Hb, Hd, r, z10, z6, g and m) and H2 antigens (1.5, 1.2, 1.6 and enx). Overall, the multiplex PCRs of O, H and Vi antigens results correctly serotyped 94 of 122 strains (77%). The most frequent serovars encountered were Salmonella weltevrerden, Salmonella enteritidis, Salmonella typhimurium, Salmonella hadar and Salmonella typhi. Application of DNA based technique for serogrouping and serotyping of the selected Salmonella enterica was found to be robust, quick, specific and reliable for the specific antigenic targets and is useful in the study area which lack complete serotyping facilities.

Characterization of 13 multi-drug resistant Salmonella serovars from different broiler chickens associated with those of human isolates

BackgroundSalmonella are frequently isolated from chickens and their products. Prevalent serogroups and serovars of Salmonella as well as their genotypes and antibiograms were determined for cloacal samples from 1595 chickens. To understand the possible serovar and H antigens for transmission between chicken and human, serovars and their H antigens of 164 chicken and 5314 human isolates were compared.ResultsPrevalence of Salmonella differed among chicken lines and ages. Chicken and human isolates belonged mainly to serogroup B, C1, C2-C3, D, and E. 13 serovars and 66 serovars were identified for chicken and human isolates respectively. The common serovars for chicken and human isolates were S. Typhimurium, S. Enteritidis, S. Albany, S. Derby, and S. Anatum and shared common H1 antigens "g complex; i; e,h; and z4,z24" and H2 antigens "1 complex and -". In human isolates, H1 antigen "i" and H2 antigen "-" were common in all serogroups. In chicken, antimicrobial susceptibility differed among serogroups, serovars and three counties. All isolates were susceptible to cefazolin and ceftriaxone, but highly resistant to ampicillin, chloramphenicol, flumequine, streptomycin, sulfamethoxazole-trimethoprim, and tetracycline. Except those isolates of serogroup C1 of Chick group and serogroup G, all isolates were multi-drug resistance. Only S. Kubacha, S. Typhimurium, S. Grampian, and S. Mons were resistant to ciprofloxacin and/or enrofloxacin.ConclusionIn chicken, prevalent serogroups and serovars were associated with chicken ages, lines and regions; and flouroquinolone-resistant and MDR isolates emerged. H1 antigens "g complex and i" and H2 antigens "1 complex and -" might be important for transmission of Salmonella between chicken and human.

Clonal dissemination of the multi-drug resistant Salmonella enterica serovar Braenderup, but not the serovar Bareilly, of prevalent serogroup C1 Salmonella from Taiwan

BackgroundNontyphoidal Salmonella is the main cause of human salmonellosis. In order to study the prevalent serogroups and serovars of clinical isolates in Taiwan, 8931 Salmonellae isolates were collected from 19 medical centers and district hospitals throughout the country from 2004 to 2007. The pulsed-field eletrophoresis types (PFGE) and antibiotic resistance profiles of Salmonella enterica serovars Bareilly (S. Bareilly) and Braenderup (S. Braenderup) were compared, and multi-drug resistance (MDR) plasmids were characterized.ResultsOver 95% of human salmonellosis in Taiwan was caused by five Salmonella serogroups: B, C1, C2-C3, D1, and E1. S. Typhymurium, S. Enteritidis, S. Stanley and S. Newport were the four most prevalent serovars, accounting for about 64% of isolates. While only one or two major serovars from four of the most prevalent serogroups were represented, four predominant serovars were found in serogroup C1 Salmonellae. The prevalence was decreasing for S. Choleraeuis and S. Braenderup, and S. Virchow and increasing for S. Bareilly. S. Braenderup mainly caused gastroenteritis in children; in contrast, S. Bareiley infected children and elderly people. Both serovars differed by XbaI-PFGE patterns. Almost all S. Bareilly isolates were susceptible to antibiotics of interest, while all lacked plasmids and belonged to one clone. Two distinct major clones in S. Braenderup were cluster A, mainly including MDR isolates with large MDR plasmid from North Taiwan, and cluster B, mainly containing susceptible isolates without R plasmid from South Taiwan. In cluster A, there were two types of conjugative R plasmids with sizes ranging from 75 to 130 kb. Type 1 plasmids consisted of replicons F1A/F1B, blaTEM, IS26, and a class 1 integron with the genes dfrA12-orfF-aadA2-qacEΔ1-sulI. Type 2 plasmids belonged to incompatibility group IncI, contained tnpA-blaCMY-2-blc-sugE genetic structures and lacked both IS26 and class 1 integrons. Although type 2 plasmids showed higher conjugation capability, type 1 plasmids were the predominant plasmid.ConclusionsSerogroups B, C1, C2-C3, D1, and E1 of Salmonella caused over 95% of human salmonellosis. Two prevalent serovars within serogroup C1, S. Bareilly and cluster B of S. Braenderup, were clonal and drug-susceptible. However, cluster A of S. Braenderup was MDR and probably derived from susceptible isolates by acquiring one of two distinct conjugative R plasmids.

Salmonella spp. in Bavarian Liquid Pig Manure: Occurrence and Relevance for the Distribution of Antibiotic Resistance

In a representative study, 380 manure samples of pig farms distributed all over Bavaria (Germany) were screened for the presence of Salmonella spp. at the time of manure application to soil using methods adapted to DIN EN ISO 6579. The isolates were tested according to DIN 58940 for their susceptibility towards 26 antimicrobial substances - such substances partly administered in animals, but mainly used in human therapy. Six out of 380 manure samples and, in addition, the only separated liquid manure sample examined, contained Salmonella isolates. Serotypes represented S. Typhimurium (n = 5), S. Derby (n = 1) and S. Infantis/S. Serogroup C1-(6,7:r:-)-form (each n = 1). Within the serovar S. Typhimurium, the most common phage type was DT104 (n = 3). All Salmonella isolates originated from 'big' farms (>30/45 sows on combined/breeding farms or >220 fattening pigs). Four out of six manure samples contained resistant isolates; all resistant Salmonellae were multi-resistant. Two out of three DT104-isolates showed the typical penta-resistance pattern often found in S. Typhimurium DT104, which was, furthermore, supplemented by other resistances. One Escherichia coli isolated together with a phage type DT104 S. Typhimurium also expressed the same penta-resistance pattern.

Assessing the Prevalence of Salmonella enterica in Poultry Hatcheries by Using Hatched Eggshell Membranes

Salmonella enterica causes a number of significant poultry diseases and is also a major pathogen in humans. Most poultry infected by Salmonella become carriers; infection may also be fatal, depending on the particular serovar and the age of the bird at infection. Younger birds are more susceptible to infection by Salmonella, so it is critical that hatcheries monitor birds. We developed a method to use hatched eggshell membranes (HEM) to assess contamination by Salmonella in poultry hatching cabinets and to evaluate the prevalence of Salmonella in a goose hatchery and rearing farm. Comparison of the Salmonella isolation rate in hatching cabinets using 3 sampling methods showed that the highest Salmonella contamination was detected in HEM, and that these results differed significantly from those obtained from fluff samples and cabinet swab samples (P < 0.05). Analysis of HEM was also used to evaluate Salmonella contamination in goose, chicken, and duck hatcheries. The lowest Salmonella-positive rate was found for the chicken hatchery, followed by the goose and the duck hatcheries (P < 0.05). Six serogroups of Salmonella were detected in the 3 hatcheries: A, B, C1, C2, D, and E. The distribution of these serogroups differed among the hatcheries. Salmonella serogroup C1 was the major serogroup found in geese, compared with serogroup B in chickens and ducks. However, Salmonella Typhimurium was dominant in 1 goose hatchery and also in geese from this hatchery that had been transferred to a farm. Antibiotic susceptibility analysis showed that Salmonella Typhimurium strains isolated from the farm geese with diarrhea showed significantly higher resistance to doxycycline, colistin, sulfamethoxazole-trimethoprin, and cephalothin than those isolated from the hatchery (P < 0.05). Therefore, HEM as a detection target can be used to monitor Salmonella contamination in hatching cabinets and also be used to assess Salmonella prevalence in poultry hatcheries and rearing farms.

Movement and Persistence of Salmonella in Broiler Chickens following Oral or Intracloacal Inoculation

The dissemination of Salmonella into various lymphoid-like organs in young broiler chicks after oral and intracloacal inoculation was studied. A three-strain cocktail of Salmonella Typhimurium, Salmonella Montevideo, and Salmonella Enter-itidis was administered either orally or intracloacally to day-old chicks. After 1 h, 1 day, or 1 week, the ceca, thymus, liver and gallbladder, spleen, and bursa were sampled for the presence of Salmonella. There was a marked difference in the recovery of Salmonella 1 h postinoculation. Only 6 of 50 samples from orally inoculated chicks were positive compared with 33 of 50 samples from cloacally inoculated samples. In comparison, 24 h and 1 week after inoculation, there was no difference in the number of positive samples between oral or cloacal inoculation. The rapidity of the translocation of the Salmonella from the cloacal inoculum compared to the oral inoculum is likely due to the transient time required for Salmonella to move through the alimentary tract. The method of inoculation did not affect the distribution of serogroups. Of the three serotypes in the composite inoculum, the Salmonella Enteritidis (group D) was recovered only twice in replication 1 and not at all in replication 2. Both the Salmonella Typhimurium (serogroup B) and the Salmonella Montevideo (serogroup C1) were recovered extensively throughout the study.

Detection of InvA Gene in Isolated Salmonella from Broilers by PCR Method

The presence of Salmonella was detected in 192 samples of poultry carcasses from poultry farms in Shiraz province (Iran). A total of 30 Salmonella isolates were found in chicken samples (15.6%), by conventional culturing and confirmed by PCR and serology methods. Strains of serogroup D1 were the most prevalent strains, followed by serogroups C1, B and C2. All strains were subjected to Salmonella-specific gene (invA) and were confirmed as Salmonella positive by the predicted product a 284-bp DNA fragment.

Salmonella profile in chickens determined by real-time polymerase chain reaction and bacteriology from years 2000 to 2003 in Turkey

From years 2000 to 2003, Salmonella was investigated from a total of 1785 samples comprised of chicken intestinal samples, cloacal swabs, drag swabs, litter samples and chick dust samples collected from 191 poultry breeding flocks belonging to 15 different chicken breeding stock companies in the Marmara region, Turkey by a SYBR green-based real-time polymerase chain reaction (SGBRT-PCR), by a probe-specific real-time polymerase chain reaction (PSRT-PCR) and by standardized bacteriology as described in the manual of National Poultry Improvement Plan and Auxillary Provisions, United States Department of Agriculture. Between January 2000 and July 2001, Salmonella was detected at the rates of 5.87% and 4.10% out of a total of 1242 samples by SGBRT-PCR and bacteriology, respectively. From July 2001 until December 2003, Salmonella was found at rates of 11.42% and 5.52% from a total of 543 samples by PSRT-PCR and bacteriology, respectively. The dominant Salmonella serovar was determined as Salmonella enterica subsp. enterica Serovar Enteritidis (S. Enteritidis), while serogroup C1 and C2 in 2001 and serogroup E1 in 2002 were isolated as additional serovars. As a conclusion, S. Enteritidis seems to be the major problem in poultry breeding flocks in Turkey, and both of the real-time polymerase chain reaction methods were found more sensitive than standard bacteriology for the detection of Salmonella from poultry samples.

Emerging nalidixic acid and ciprofloxacin resistance in non-typhoidal Salmonella isolated from patients having acute diarrhoeal disease.

BackgroundNon-typhoidal Salmonella are one of the key etiological agents of diarrhoeal disease. The appearance of multiple drug resistance along with resistance to quinolones in this bacterium poses a serious therapeutic problem. We determined the prevalence of nalidixic acid and ciprofloxacin resistance in non-typhoidal Salmonella isolated from faecal samples of patients with acute diarrhoeal disease attending the outpatient and inpatient department of a hospital in Saudi Arabia during the years 1999 to 2002.MethodsNon-typhoidal Salmonella were isolated from faecal samples. Antimicrobial susceptibility was tested by the disc diffusion test. MICs to nalidixic acid and ciprofloxacin were determined by the agar dilution method.ResultsDuring the study period, 524 strains of non-typhoidal Salmonella were isolated. Strains belonging to serogroup C1 were the commonest (41.4%) followed by serogroups B and D (15.6% and 14.5%, respectively). Resistance to ampicillin was observed in 22.9% and to trimethoprim/sulfamethoxazole in 18.5% of the strains. Nalidixic acid resistance was encountered in 9.9% and ciprofloxacin resistance in 2.3% of the strains. Resistance to nalidixic acid significantly increased from 0.1% in 1999 to 5.5% in 2002 (P=0.0007) and ciprofloxacin resistance increased significantly from 0.1% in 1999 to 0.9% in 2002 (P=0.0001). MICs to nalidixic acid and ciprofloxacin were determined among 29 nalidixic acid-resistant strains of non-typhoidal Salmonella isolated during 2002. The MIC was >256 μg/mL to nalidixic acid and 8 to 16 μg/mL to ciprofloxacin.ConclusionThe increasing rates of antimicrobial resistance encountered among non-typhoidal Salmonella necessitate the judicious use of these drugs in humans. Moreover, these findings support the concern that the use of quinolones in animal feed may lead to an increase in resistance and should be restricted.

Emerging nalidixic acid and ciprofloxacin resistance in non-typhoidal Salmonella isolated from patients having acute diarrhoeal disease.

BackgroundNon-typhoidal Salmonella are one of the key etiological agents of diarrhoeal disease. The appearance of multiple drug resistance along with resistance to quinolones in this bacterium poses a serious therapeutic problem, We determined the prevalence of nalidixic acid and ciprofloxacin resistance in non-typhoidal Salmonella isolated from faecal samples of patients with acute diarrhoeal disease attending the outpatient and inpatient departments of a hospital in Saudi Arabia during the years 1999 to 2002.MethodsNon-typhoidal Salmonella were isolated from faecal samples. Antimicrobial susceptibility was tested by the disc diffusion test MICs to nalidixic acid and ciprofloxacin were determined by the agar dilution method.ResultsDuring the study period, 524 strains of non-typhoidal Salmonella were isolated Strains belonging to serogroup C1 were the commonest (41.4%) followed by serogroups B and D (15.6% and 14.5%, respectively), Resistance to ampicillin was observed in 22.9% and to trimethoprim/sulfamethoxazole in 18.5% of the strains. Nalidixic acid resistance was encountered in 9.9% and ciprofloxacin resistance in 23% of the strains. Resistance to nalidixic acid significantly increased from 0.1% in 1999 to 5.5% in 2002 (P=0.0007) and ciprofloxacin resistance increased significantly from 0.1% in 1999 to 0.9% in 2002 (P=0.0001). MICs to nalidixic acid and ciprofloxacin were determined among 29 nalidixic acid-resistant strains of non-typhoidal Salmonella isolated during 2002. The MIC was >256 μg/mL to nalidixic acid and 8 to 16 μg/mL to ciprofloxacin.ConclusionThe increasing rates of antimicrobial resistance encountered among non-typhoidal Salmonella necessitate the judicious use of these drugs in humans. Moreover, these findings support the concern that the use of quinolones in animal feed may lead to an increase in resistance and should be restricted.