Seran Temelli

Evaluation of ISO 6579 and FDA-BAM Methods to Complement Real-Time Polymerase Chain Reaction for the Detection of Salmonella in Naturally Contaminated Poultry Meat and Red Meat

In this study, we evaluated the Salmonella detection capability and compatibility of a LightCycler polymerase chain reaction (LC PCR) system with two bacteriological methods, United States Food and Drug Administrations Bacteriological Analytical Manual Chapter 5: Salmonella (FDA) and International Organization for Standardization Method 6579 (ISO). The aim was to determine which bacteriological method would support LC PCR for testing naturally contaminated poultry and red meat samples with Salmonella. Twenty three (50.0%) and 24 (52.2%) out of 46 chicken meat samples were positive for Salmonella by the FDA and ISO methods, respectively. Five of the 15 (33.3%) turkey meat samples were found to harbor Salmonella by both bacteriological methods. None of the red meat samples were positive for Salmonella using the FDA method. There was one red meat sample (3.3%) positive for Salmonella using ISO method. LC PCR results indicated that 23 (50.0%) and 31 (67.4%) of the DNA templates obtained from the 46 preenriched chicken meat FDA and ISO samples were positive for Salmonella. Salmonella detection rate from turkey meat samples by ISO LC PCR was 6.7%, whereas no detection was observed by FDA LC PCR. FDA LC PCR detection rate in red meat samples was 23.3%, whereas the ISO LC PCR was 43.3%. Relative accuracy rates of ISO LC PCR and FDA LC PCR were 67.4%, 60.0%, 53.3% and 56.5%, 66.7%, 76.7% for chicken, turkey, and red meats, respectively. We presume that the low relative accuracy problem, which can be related to the use of FDA and ISO preenrichments for template preparations in the PCRs, can be overcome by the use of primary enrichments of both FDA and ISO bacteriologies.

Real-time PCR culture and serology for the diagnosis of Mycoplasma gallisepticum in chicken breeder flocks.

This study aimed to compare a real-time PCR (rPCR) test with improved detection limit to serology and culture for the detection of Mycoplasma gallisepticum (MG) infection in chicken breeder flocks. Six hundred and forty-six blood and tracheal swab samples belonging to 31 grandparent chicken breeder flocks were tested by rPCR. The detection limit of rPCR was 0.9 pg microl(-1), with pure MG S6 strain DNA and 100 colony forming units (CFUs) ml(-1), where both pure culture and tracheal swabs were artificially spiked with the same strain. The seropositive flock rate based on both MG RPA and HI were calculated as 48.4% (15/31) and 32.3% (10/31), respectively, while culture- and rPCR-positive flock rates were 16.1% (5/31) and 29.0% (9/31), respectively. On flock-based analysis, culture method detected 5 out of 10 MG seropositive flocks (sensitivity 50%, specificity 100%), whereas rPCR detected 8 out of 10 flocks (sensitivity 80%, specificity 95%). Agreements between serology and culture, and serology and rPCR were 83.9% and 90.3%, respectively. On individual sample-based analysis, culture method detected 26 out of 78 MG seropositive chicken (sensitivity 33%, specificity 100%), whereas rPCR detected 51 out of 78 MG seropositive chickens (sensitivity 65%, specificity 96%). There was 91.9% and 91.4% agreement between serology and culture, and serology and rPCR, respectively. Results of this study indicate that the rPCR with improved in vitro detection limit could detect MG in seropositive chicken flocks. Therefore, we advise the use of rPCR and/or culture for confirmation of serology results obtained from screening MG infection in chicken flocks.

Salmonella Serogroup Detection in Poultry Meat Samples by Examining Multiple Colonies from Selective Plates of Two Standard Culture Methods

This study aims to determine the serogroup profiles of randomly collected 46 chicken meat and 15 turkey meat samples, following the U.S. Food and Drug Administrations (FDA) Bacteriological Analytical Manual Chapter 5: Salmonella and International Organization for Standardization (ISO) Method 6579 culture methods. The total number of poultry meat samples with more than one serogroup isolated by the FDA and ISO culture methods were 10 (37.0%) and 21 (77.8%) of 27, respectively. Presence of multiple serogroups per sample was more frequently observed in chicken meat samples than in turkey meat samples. The profile of Salmonella serogroup isolates of chicken meat samples in descending order were serogroups D and E4 (15.8%), B and C2 (8.8%), C1 (5.3%), G (3.5%), and E1 and F (1.7%). The serogroup distribution of turkey meat sample isolates were serogroups B (27.2%), E4 (18.2%), and C2 (9.1%). On the basis of our findings that a selective plate in Salmonella culture method can harbor more than one serogroup, and that the FDA and ISO methods could detect different serogroups from chicken and turkey meats, we suggest screening multiple suspect colonies from each plate, if possible, and considering the collective and comparative use of the FDA and ISO culture methods and/or including several selective and differential media to ensure the detection of Salmonella and the possible detection of multiple serogroups from samples.

Sığır mastitislerinden izole edilen Escherichia coli suşlarında genişlemiş spektrumlu beta-laktamaz aktivitesi ve antibiyotik dirençlilik profilinin incelenmesi

Özet: Bu çalışmada Ankara, Balıkesir ve Çorum’daki süt işletmelerinden sağlanan mastitis şüpheli sütlerden izole edilen 92 adet E. coli suşunda genişlemiş spektrumlu beta-laktamaz (GSBL) aktivitesi ve antibiyotik direnç profilinin araştırılması amaçlandı. E. coli suşlarında Kirby Bauer disk diffüzyon yöntemi ile GSBL tarama testi, fenotipik GSBL doğrulama testi ve 12 adet antibiyotik için in vitro duyarlılık testleri yapıldı. İncelenen E. coli suşlarında en yüksek dirençlilik oranları sırasıyla eritromisine (%69.6), ampisiline (%39.1), tetrasikline (%34.8), nalidiksik aside (%25.0), kloramfenikole (%22.8), trimetoprim-sülfametaksazole (%21.7) ve amoksisilin klavulonik aside (%21.7) karşı bulunurken, suşların %25.0’inin kullanılan tüm antibiyotiklere duyarlı olduğu saptandı. Ayrıca E. coli suşlarının %54.3’ünün iki veya daha fazla sayıda antibiyotiğe dirençli olduğu belirlendi. Bu çalışma ile ülkemizde mastitis orijinli E. coli suşlarında ilk kez GSBL aktivitesi araştırıldı. Ancak, incelenen E. coli suşlarında GSBL aktivitesi saptanmadı. Çalışmada elde edilen bulgular mastitise neden olan E. coli suşlarında yüksek oranda çoğul ilaç direncinin geliştiğini gösterdi. Anahtar sözcükler: Antibiyotik dirençlilik, E. coli, GSBL, mastitis.