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https://hdl.handle.net/20.500.12587/17942

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Determination of Subtypes, Serogroups, And Serotypes, Virulence, and/ or Toxigenic Properties of Escherichia coli Isolated From Cattle, Sheep, and Goat Feces by Multiplex PCR
(Kafkas Univ, Veteriner Fakultesi Dergisi, 2024) Kızıl, Sibel; Aydın, Fatma Esin; Önel, Aziz Utku; Yıldırım, Murat; Güneri, Cansu Önlen; Çeçen, Efsun Melike
In the study, rectal swabs taken from 300 ruminant animals including cattle (100), sheep (100), and goats (100) were inoculated into Mac Conkey Agar and incubated for 18 h at 37degree celsius. Escherichia coli isolates were confirmed by biochemical tests and the BBL Crystal rapid diagnosis system. O26, O45, O103, O111, O121, O145, and O157 serotypes by PCR test following DNA isolation; ETEC (elt, Stla); EPEC (eaeA,bfpA); STEC (stx1, stx2, eaeA); EHEC (EhlyA); EAEC (CVD432) tested for virulence and/or toxigenic genes. As a result of the isolation studies, 50 E. coli from cattle feces, 92 from sheep feces, and 80 from goat feces were isolated and identified. Apart from the first 5 serotypes frequently seen in studies (O157, O26, O103, O111, and O145), higher rates were found in serogroups such as O45 and O121, and subtypes such as STECs (stx1 and stx2), EPEC (eaeA and bfpA) and EAEC (CVD432) types compared to other studies. The EAEC (CVD432) subtype was found to be very high in this study. It has been determined that serotypes and subtypes detected at high rates in cattle, sheep, and goat feces in our region may cause an increase in the incidence of some critical food-borne infections in humans. Within the framework of the concept of one health, taking the necessary precautions is important for public health.
Comparison of milk microbiota between healthy and mastitic cows
(Tubitak Scientific & Technological Research Council Turkey, 2024) Kızıl, Sibel; Aydın, Fatma Esin; Önlen Güneri, Cansu; Ülker, Ufuk; Emekdaş, Gürol; Basmacı, İbrahim; Erat, Serkan
Mammary gland infections occur due to bacterial changes in the mammary tissue. Studies conducted in recent years have reported variations in the most common bacteria differ according to geographical locations. California mastitis test (CMT), somatic cell count (SCC), and aerobic colony count (ACC) analyses were performed on approximately 50 mL of hygienically collected raw milk samples. Raw milk was also subjected to conventional bacteriological isolation and identification. Bacterial diversity and rates in raw milk were compared through metagenome analysis. Two samples, one from healthy milk and another from subclinical milk with mastitis, were independently tested to determine whether there were differences in the percentages (%) of bacterial phylum and genera detected as a result of metagenome analysis. As a result of the conventional isolation and identification of raw milk, EscherichiaShigella, Acinetobacter, Vibrio, Streptococcus, Pseudomonas, Lactococcus, Glutamicibacter and Bacillus genera, and Enterobacteriaceae family were frequently detected, respectively. As a result of metagenome analysis, the following phyla were detected in healthy raw milk: Firmicutes and Proteobacteria (7/7), Bacteroidota (6/7), and Actinobacteriota (4/7). In raw milk with subclinical mastitis, the detected phyla were Firmicutes and Proteobacteria (27/29), Actinobacteriota (11/29), and Bacteroidota (10/29). As a result of the statistical analysis, the frequency of Bacteriodata in healthy milk samples, as well as Enhydrobacter, Enterobacteriaceae, Paenibacillus, Macrococcus, Spingobacterium, and Others, were significantly higher than the incidence in milk samples with subclinical mastitis. The only exception was observed in Escherichia-Shigella genera, where the opposite situation was evident. As a result of metagenome studies conducted on the raw milk of animals with both healthy and subclinical mastitis, significant differences were detected in some phyla and genera. The findings of our study will shed light on mastitis treatment studies by improving the microbiota.
Broyler damızlık ve ticari broyler sürülerinde tavuk anemi virüsünün ve antikor varlığının araştırılması
(2011) Aşkar, Şinasi; Yıldırım, Murat
Bu çalışmada, tavuk anemi hastalığına (chicken infectious anemia-CIA) karşı aşılı ve aşısız broyler damızlık sürülerinde tavuk anemi virüs (chicken anemia virus-CAV) antikor varlığını ve bu damızlıkların ticari broyler sürülerinde CAV maternal antikor seyrini, antikor ve VP1 ile VP2 gen varlığını araştırmak amaçlandı. Çalışmada enzyme-linked immunosorbent assay (ELISA) ile polymerase chain reaction (PCR) testleri kullanıldı. Haziran 2008- Şubat 2009 tarihleri arasında CIA hastalığına karşı 6’sı aşılı, 6’sı aşısız broyler damızlık sürülerinden toplam 218 kan serumu ve bu damızlıkların 32 ticari broyler sürüsünden belirli aralıklarla toplam 2074 kan serumu ve 1916 doku örneği elde edildi. Aşılı ve aşısız damızlıklar seropozitif saptanırken, ortalama antikor titreleri karşılaştırıldığında istatistikî olarak önemli bir fark olmadığı belirlendi. Aşılı ve aşısız damızlıkların günlük ve 1 haftalık ticari broyler sürülerinde maternal antikor oranının % 98 - 100, 2 haftalıkken % 5 – 60, 3 haftalıkken % 0 - 15 arasında olduğu belirlendi. Aşılı damızlıkların 4 haftalık 8 ticari broyler sürüsünün % 62.5’inde, 5 haftalık 16 ticari broyler sürüsünün % 93.8’inde CAV antikor varlığı belirlendi. Aşılı damızlıkların 3 haftalık 8 ticari broyler sürüsünün % 25’inde, 4 haftalık 8 ticari broyler sürüsünün % 37.5’inde, 5 haftalık 16 ticari broyler sürüsünün % 37.5’inde VP1 ve VP2 gen varlığı belirlendi. Aşısız broyler damızlıkların ticari broyler sürülerinde ise CAV antikor ve VP1 ile VP2 gen varlığı tespit edilmedi.
İneklerin süt, meme başı derisi ve burun mukozalarından izole edilen stafilokok türlerinin antibiyotik direnç profilleri
(2010) Ünal, Nilgün; Yıldırım, Murat
Bu çalışmada, sağmal ineklerden alınan süt, meme başı derisi ve burun mukozası sürüntü örneklerinden izole ve identifiye edilen stafilokok türlerinin küçük ve orta ölçekli işletmelerdeki dağılımı ve çeşitli antibiyotiklere direnç profillerinin belirlenmesi amaçlanmıştır. Kırıkkale ve çevresinde bulunan ve rastgele seçilen 14 adet küçük ölçekli ve 5 adet orta ölçekli süt sığırcılığı işletmesinde bulunan 109 baş sağmal inekten örnekler alınmıştır. Alınan örneklerden stafilokokların izolasyon ve identifikasyonu için biyokimyasal testler ve ticari kit (Kristal Gram-Pozitif İdentifikasyon Kiti, Becton Dickinson, USA) kullanılmıştır. Stafilokokların çeşitli antibiyotiklere direnç özellikleri disk difüzyon metodu ile belirlenmiştir. Tüm izolatların metisilin direncini belirlemek için sefoksitin diski ve oksasilinli agar tarama plakları kullanılmıştır. Penisilin dirençli izolatların beta-laktamaz enzimlerinin varlığı ?-laktamaz (nitrocefin) identifikasyon çubukları (Oxoid) ile belirlenmiştir. Süt örneklerinden her iki işletme tipinde de %48 oranında Staphylococcus aureus izole edilmiştir. Elle sağımın yapıldığı küçük ölçekli işletmelerde ineklerin meme başı derisinden ve burun mukozalarından S. aureus izole edilirken makineli sağımın yapıldığı orta ölçekli işletmelerde meme başı derisinden ve burun mukozalarından S. aureus izole edilememiştir. Farklı antibiyotik gruplarına ait 11 adet antibiyotik kullanılarak yapılan direnç analizlerinde kaynağa bağlı olarak oransal farklılık (burun-süt, %19.5-49.5) göstermesine rağmen en yüksek oranda direncin penisiline olduğu tespit edilmiştir. Metisilin dirençli S. aureus izole edilememiştir. Penisilin dirençli izolatların %92.7’sinde (12) ?-laktamaz enziminin varlığı ortaya konulmuştur
Çeşitli Hayvansal Klinik Örneklerden İzole Edilen Staphylococcus aureus Suşlarında Slaym Pozitifliği ve Antibiyotik Direnci
(2014) Şeker, Esra; Ünal, Nilgün
Bu çalışmada, inek sütü, inek uterus sıvabı, köpek kulak sıvabı, köpek deri sıvabı ve tavuk sinoviyal sıvı örneklerinden izole edilen toplam 50 Staphylococcus aureus suşu slaym faktör üretimi ve antibiyotik direnci yönünden incelendi. Suşların slaym üretimi Congo red agar ve standart tüp yöntemleri kullanılarak belirlendi. Elli S. aureus suşunun 21'i(%42) Congo red agarda, 18'i (%36) standart tüp yöntemi ile slaym pozitif olarak belirlendi. İki farklı yöntem arasındaistatistiksel olarak önemli bir farklılık bulunmadı (p>0.05). İzolatların antibiyotik dirençlerinin belirlenmesinde standart Etest yöntemi kullanıldı. İzolatlar arasında en yüksek direnç oranı penisilin G'ye (%20) karşı iken, bunu sefalotin (%16),oksasilin (%16) ve tetrasikline (%14) karşı direnç oranları izledi. Test edilen izolatlardan sadece biri (%2) enrofloksasine karşı dirençliydi. Eritromisin, trimetoprim/sulfametoksazol, rifampin ve gentamisine karşı ise direnç tespit edilemedi.Slaym pozitif ve negatif suşların antibiyotik dirençleri karşılaştırıldığında, slaym pozitif suşlarda penisilin G, sefalotin veoksasiline karşı direnç önemli oranda yüksekti (p<0.05)
İnsan ve sığır kökenli Staphylococcus aureus izolatlarının fenotipik ve genotipik özelliklerinin araştırılması
(2009) Ünal, Nilgün; İstanbulluoğlu, Ersin
Bu çalışma, Staphylococcus aureus izolatlarının (46 mastitisli inek sütü, 35 inek meme başı derisi, 3 inek burun, 3 bakıcı el ve 9 bakıcı burun sürüntü örneğinden) E-test metoduyla çeşitli antibiyotiklere karşı duyarlılık profilleri ile plazmid ve Pulsed Field Gel Elektroforez (PFGE) analizleriyle genotipik özelliklerini belirlemek amacıyla yapıldı. E-test sonuçlarına göre, S. aureus izolatlarının penisilin G, tetrasiklin, eritromisin, oksasilin ve enrofloksasin dirençleri sırasıyla %85.4 (82), %39.6 (38), %5.2 (5), %3.1 (3) ve %1.0 (1) olarak belirlendi. Plazmid analizleri ile 9 farklı tipte plazmid profili belirlendi. Analizleri yapılan izolatların 87 (%90.6) tanesinde 1.8-19 kb arasında değişen büyüklükte on farklı plazmid belirlendi ve izolatların 9 tanesinde (%9.4) plazmid saptanamadı. PFGE tiplendirme verilerine göre S. aureus izolatları genetik yakınlık bakımından 42 farklı paterne ve 13 ana gruba (A, B, C, D, E, F, G, H, I, J, K, L, M) ayrıldı. İzolatların % 58.3’ü (56 adet) A pulsotipinde gruplandırıldı. Sonuç olarak plazmid analizleri ve PFGE verilerine göre, Kırıkkale ve çevresindeki süt sığırcığı işletmelerinde mastitislerden sorumlu yaygın bir S. aureus klonunun var olduğu görüldü.
At fekal orijinli Escherichia coli izolatlarında antimikrobiyal direnç ve genişlemiş spektrumlu beta laktamaz üretiminin araştırılması
(2016) Örnek, Gamze; Ünal, Nilgün
Bu çalışma, düz yarış ve konkur atlarından alınan fekal örneklerden izole edilen Escherichia coli izolatlarının çeşitli antibiyotiklere direnç durumlarını belirlemek ve genişlemiş spektrumlu beta laktamaz (GSBL) varlığını araştırmak amacıyla yapıldı. Çalışmada izole edilen 100 E. coli (düz yarış: 37, konkur: 63) izolatının 16 antibiyotiğe karşı duyarlılıkları disk difüzyon yöntemiyle, GSBL varlığı ise fenotipik doğrulama testi ile belirlendi. Düz yarış ve konkur grupları arasında antibiyotik direnç oranları karşılaştırıldı. En yüksek antibiyotik direnci, düz yarış atlarında %81.1 (30/37) ve konkur atlarında %20.6 (13/63) oranlarında olmak üzere tetrasikline karşı belirlendi. Atlardan izole edilen 100 E. coli izolatının ise 6 (%6) tanesinde GSBL üretimi fenotipik olarak doğrulandı. GSBL pozitif izolatların tümü düz yarış atlarından izole edildi. Sonuç olarak, düz yarış atlarının fekal florasından elde edilen E. coli izolatlarında çeşitli antibiyotiklere direnç daha yüksek oldu ve bu izolatlarda GSBL üretimi belirlendi. Bu etkenlerin ekosisteme bulaşması halk sağlığı açısından potansiyel bir risk oluşturabilir
Subklinik mastitisli inek sütlerinden izole edilen Staphylococcus aureus izolatlarında bazı toksin genleri ve metisilin direnç geninin araştırılması
(2013) Ünal, Nilgün
Bu çalışma subklinik mastitisli inek sütlerinden izole edilen Staphylococcus aureus izolatlarında bazı stafilokokal enterotoksin, Panton-Valentine lökosidin genleriyle metisilin direnç geninin araştırılması amacıyla yapılmıştır. Araştırmada 60 S. aureus izolatı kullanılmış ve genlerin belirlenmesinde polimeraz zincir reaksiyonundan yararlanılmıştır. İzolatların sekizinde (% 13.33) seg-sei, altısında (% 10.00) sej, dördünde (% 6.67) sec ve üçünde (% 5.00) ise seh geni belirlenmiştir. Toplam on altı (% 26.67) izolatta bir veya daha fazla enterotoksin geni tespit edilmiştir. İncelenen izolatlarda enterotoksin genlerinden sea, seb, sed, see ve tsst belirlenemezken dördünde (% 6.6) Panton-Valentine lökosidin geni ve ikisinde (% 3.30) metisilin direnç geni belirlenmiştir. Sonuç olarak subklinik mastitisli sütlerde bulunan S. aureus izolatlarının enterotoksin üretebilecekleri ve metisilin direnç geni taşıyabilecekleri belirlenmiştir. Bu durum halk sağlığı açısından önemli bir risk oluşturmaktadır.
Molecular and Serological Characterization of Pestivirus Infection Among Sheep in Kirikkale, Turkey
(2011) Azkur, Ahmet Kürşat; Gazyağcı, Serkal; Aslan, Muhammet Eren; Ünal, Nilgün
Border hastalığı virüsü koyun sürülerinde ekonomik kayıplara neden olur ve dünyada yüksek seroprevalansa sahiptir. Bu çalışmada Kırıkkale ili ve tüm ilçelerinde bulunan 25 koyun sürüsünden elde edilen 1075 örneği kullanılmıştır. Pestivirüse karşı oluşan antikorlar 1075 serumun %74.51'inde ELISA kullanılarak tespit edilmiştir. Bununla birlikte, seropozitifl ik oranlarının her bir koyun sürüsünde %8.4 ve %100 arasında değişmektedir. Seropozitifl ik ve ırk,yaş ve cinsiyet arasındaki ilişki araştırıldı. Seropozitifl ik, cinsiyet ve yaş arasında bir bağlantı tespit edilemezken, koyun ırkları ve pestivirüse karşı oluşan pozitif antikor cevabı arasında istatistiksel olarak anlamlı bir ilişki tespit edildi (P<0.05). Virüs tespiti çalışmaları, virüs enfekte pestivirüse karşı antikor oluşturmayan hayvanların oranının %4.37 olduğunu göstermiştir. Moleküler aşamada enfekte virüsün 5'UTR bölgesi tersine transkripsiyon ve nested PZR ile çoğaltıldı. PZR sonrası sekans analizi ve filogenetik analiz yapıldı. Buna göre koyun sürülerini enfekte eden virüs Türkiye'de daha önceden bildirilen BDV suşlarından farklı fakat pestivirüs tip 3 ile çok yakın antijenik benzerliği olduğu belirlendi.
Extended-spectrum ?-lactamases among cloacal Escherichia coli isolates in healthy broilers in Turkey
(2017) Ünal, Nilgün; Karagöz, Alper; Aşkar, Şinasi; Dilik, Zahide; Yurteri, Buket
The aim of this study was to determine the prevalence and clonal typing of extended-spectrum beta-lactamase (ESBL)- producing Escherichia coli in healthy broilers in Turkey. Three hundred broiler cloacal samples were collected from various broiler slaughterhouses and inoculated on Levine agar plates supplemented with 2 μg/mL cefotaxime. Suspected strains were identified using a BBL Crystal Enteric/Nonfermenter ID Kit (Becton Dickinson, USA) and ESBL production was confirmed using an ESBL phenotypic confirmatory test. ESBL types were analyzed using PCR and sequencing. Pulsed field gel electrophoresis (PFGE) was performed with XbaI for the clonal typing of ESBL-producing E. coli isolates. While 33 phenotypic ESBL-producing E. coli isolates were identified, eight of them had only the blaTEM-1. Twenty-five ESBL-producing isolates were detected. This research is the first on the investigation and detection of ESBL-producing E. coli isolates from broilers in Turkey. In this study, 8.3% ESBL-producing E. coli were isolated from the cloacal samples of broilers collected from slaughterhouses in Turkey. CTX-M-15 (80%) was the most frequently isolated ESBL type. Using PFGE analysis, it was determined that these isolates had clonal similarity.
Extended Spectrum Beta-Lactamase (ES beta L), AmpC and carbapenemase activities and colistin resistance of Salmonella spp. isolated from food poisoning cases in Turkey
(SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, 2020) Kizil, Sibel
This study aims at detecting antimicrobial resistance properties including extended spectrum beta-lactamase (ESBL), AmpC, carbapenemase activities (imipenem, meropenem and ertapenem), and colistin resistance of isolated and serotyped Salmonella spp. strains from various foods (mostly chicken and chicken products) that cause food poisoning. The ISO 6579-3 (Kaufmann-White scheme) method was used for serotyping of Salmonella spp. and for detection of antimicrobial resistance with Minimum Inhibitory Concentration (MIC) as reported by EURL-AR. Inoculums were separated into EUVSEC and EUVSEC2 panels using the Sensititre AIM Automated Inoculation Delivery System. The results were monitored in a semiautomatic vision reader and evaluated according to EUCAST Resistance to 14 different antibiotics of 34 serotyped Salmonella spp. strains were examined in the first panel in this study. Most of these strains were found to be resistant to ciprofloxacin, colistin, nalidixic acid, sulfonamides, tetracycline, tygecycline, and trimethoprim. Nine of these agents (26.4%) were determined as single-drug resistant and 20 of them (55.8%) were determined as multidrug-resistant. Only 2 strains were determined to be resistant to cefotaxime and ceftazidime; however, BBL activity was not observed in the second stage of the analysis, in which EUVSEC2 panels were used. All the strains for carbapenemase activities were determined as sensitive to imipenem, meropenem, and ertapenem. Also, all the strains for AmpC activities were found to be sensitive to cefoxitin. The same resistance properties of the isolates were detected against nalidixic acid, ciprofloxacin, and tetracycline. Colistin resistance was detected as 44.1%. Salmonella spp. strains isolated from foods that caused food poisoning were determined as multidrugresistant to antibiotics at a high rate. This study is the first one in Turkey that has evaluated ESBL, AmpC, carbapenemase activity, and colistin resistance of Salmonella spp., which was isolated from the food poisoning cases, by using MIC test (recommended by EURL-AR). In Turkey, antibiotics use should be avoided especially in chicken farms in order to prevent the increasing multidrug resistance of Salmonella spp.
Development and validation of SYBR Green- and probe-based reverse-transcription real-time PCR assays for detection of the S and M segments of Schmallenberg virus
(SAGE PUBLICATIONS INC, 2020) Azkur, Ahmet Kursat; van der Poel, Wim H. M.; Aksoy, Emel; Hakze-van der Honing, Renate; Yildirim, Murat; Yildiz, Kader
Schmallenberg virus (SBV), discovered in Germany in 2011, causes congenital malformations in ruminants. Reverse-transcription real-time PCR (RT-rtPCR) assays based on various segments of SBV have been developed for molecular detection. We developed alternative RT-rtPCR assays for SBV detection to avoid earlier reported mutations and hypervariable regions of the S and M segments of the viral genome. For SYBR Green-based detection of the S segment, theR(2)value and efficiency of the developed assay were 0.99 and 99%, respectively. For probe-based S segment detection, 2 assays were developed; the first had anR(2)value of 0.99 and 102% efficiency, and the second had aR(2)value of 0.98 and 86% efficiency. The probe-based M segment assay had anR(2)value of 1.00 and 103% efficiency. Detection limits of the RT-rtPCR assays with new primer sets were 10(2)and 10(1)copies/mu L for the S and M segments, respectively. Field samples from cattle and sheep were also used for primary validation of the developed assays. Our assays should be suitable for SBV detection in ruminants and for in vitro studies of various SBV strains.
Detection of vancomycin-resistant enterococci in samples from broiler flocks and houses in Turkey
(AKADEMIAI KIADO ZRT, 2020) Unal, Nilgun; Bal, Erhan; Karagoz, Alper; Altun, Belgin; Kocak, Nadir
Vancomycin-resistant enterococcus (VRE) is a global threat to public health. Knowledge about the occurrence of vanA-carrying enterococci in broiler and environmental samples is important as antibiotic resistance can be transferred to human bacteria. The aim of this study was to investigate the presence of VRE in broiler cloacal and environmental (house) samples and to genotype the isolates. In this study, 350 swabs were collected from broiler farms. All samples were plated onto enterococcus selective agar containing 6 mg/L vancomycin and 64 mg/L ceftazidime. Minimum inhibitory concentration (MIC) values were determined for vancomycin and teicoplanin. Vancomycin-resistant Enterococcus faecium (VREfm) was isolated from 6 out of 300 (2%) broiler cloacal samples and 13 out of 50 (26%) house samples. All E. faecium isolates had vanA genes. All VREfm isolates (19 isolates) were confirmed to be 95% similar to each other. In conclusion, although 20 years have passed since the ban on avoparcin in Turkey, the present study shows that VREfm isolates are still present in broiler production and especially in broiler houses, and most importantly, a major VREfm clone was isolated from broiler cloacal and house samples.
Optimisation of Indirect ELISA by Comparison of Different Antigen Preparations for Detection of Antibodies Against Schmallenberg Virus
(KAFKAS UNIV, VETERINER FAKULTESI DERGISI, 2020) Azkur, Ahmet Kursat; Aksoy, Emel; Yildirim, Murat; Yildiz, Kader
Schmallenberg virus (SBV) infection, discovered in 2011, was reported in Europe including Turkey, Africa and recently in some Asian countries. Commercial enzyme-linked immunosorbent assay (ELISA) kits were widely used by researchers in many epidemiological studies and SBV diagnosis. The aim of this study was to optimise indirect in-house ELISA that is based on different antigen preparations of cell-culture derived whole SBV particle. Antigen preparations were maintained with various methods: PEG precipitation, ultracentrifugation, dialysis, and antigen inactivation. Following antigen optimisation, steps of antigen coating, blocking, conjugate and stop solution were optimised and in-house ELISA was compared to commercial indirect SBV ELISA kit. The best result in ELISA antigen preparation for SBV was gained by 30% PEG purification method followed by formaldehyde inactivation. Although results of this study demonstrated that in-house ELISA for detection of SBV specific antibodies was equally sensitive and specific as commercial kit, purified SBV antigen based in-house ELISA development could increase S/P ratios.
Genotyping results of Salmonella Infantis as a food poisoning agent in Turkey between 2013 and 2017
(Scientific Technical Research Council Turkey-Tubitak, 2020) Kizil, Sibel
The aim of this study is to define the genotyping relationship between 31 Salmonella enterica subspecies enterica serovar Infantis (S. Infantis) strains, which were the most isolated and identified causes of food poisoning between 2013 and 2017 in Turkey. These isolated strains were studied with the DiversiLab System (repetitive sequence-based PCR; rep-PCR; bioMerieux, France) and traditional serotyping for the identification of S. Infantis was also carried out. Totally, 31 S. Infantis isolates were genotyped. DNA was extracted from each isolate using the Microbial DNA Isolation Kit as well as rep-PCR. The dendrogram shows the diversity of the observed samples contained in the library with 4 main clusters of S. Infantis (26 strains) being significantly different from each other with a similarity of more than 95% between strains. Furthermore, it was found that the cause of almost all of these cases originated from chicken or chicken-based products. Even though the isolated S. Infantis strains came from different geographical locations, after genotyping, their genetic profiles were found to be similar. This is the first retrospective study concerning the molecular characterization of S. Infantis isolates obtained from food poisoning cases between 2013 and 2017 in Turkey.
Development and characterization of polymeric-based nanoparticles for sustained release of amoxicillin - an antimicrobial drug
(Taylor & Francis Ltd, 2018) Guncum, Enes; Isiklan, Nuran; Anlas, Ceren; Unal, Nilgun; Bulut, Elif; Bakirel, Tulay
In this study, amoxicillin (AMO)-loaded poly(vinyl alcohol)/sodium alginate (PVA/NaAlg) nanoparticles were prepared as a polymer-based controlled release system. The physicochemical properties of the obtained nanoparticles were investigated by XRD, DSC/TGA, particle size analyses and zeta potential measurements. The average particle sizes were in the range from 336.3 +/- 25.66 to 558.3 +/- 31.39 nm with negative zeta potential values from -41.86 +/- 0.55 to-47.3 +/- 2.76 mV. The influences of PVA/NaAlg ratio, span 80 concentration, exposure time to glutaraldehyde (GA) and the drug/polymer ratio on AMO release profiles were evaluated. In vitro drug release studies showed a controlled and pH dependent AMO release with an initial burst effect. XRD patterns and DSC thermograms of AMO-loaded nanoparticles revealed that the drug in the nanoparticles was in amorphous form, which was more stable than the crystalline form. The antibacterial activity of the optimal formulation was also investigated. The minimum inhibitory concentration (MIC) values of this formulation had the comparable antibacterial activity with that of pure AMO. These results indicate that the developed nanoparticles could be a promising candidate drug delivery system for AMO.
Antibiotic resistance profile of Enterococcus faecium and Enterococcus faecalis isolated from broiler cloacal samples
(Scientific Technical Research Council Turkey-Tubitak, 2017) Unal, Nilgun; Askar, Sinasi; Yildirim, Murat
The present study was performed to isolate and identify Enterococcus spp. from broiler cloacal samples to species level, to determine their resistance patterns to various antibiotics, and to detect vancomycin resistance genes. Cloacal samples of broilers collected from slaughterhouses were inoculated in Slanetz and Bartley agars with and without vancomycin (6 mu g/mL). Antibiotic resistance/susceptibility testing of the isolated and identified enterococci was performed by using the disk diffusion test. Multiplex PCR was used to identify the species and to detect vancomycin resistance genes. The majority of the isolated enterococci was Enterococcus faecium (60.43%, n = 142) and Enterococcus faecalis (33.62%, n = 79). E. casseliflavus and E. gallinarum were identified from 8 (3.42%) and 6 (2.56%) isolates, respectively. It was found that 88.9% of the enterococci were resistant to tetracycline and 83.4% of them were resistant to erythromycin. As a result, none of the strains isolated from cloacal samples of broilers carried the vanA and vanB genes. It was observed that 54.9% of E. faecium isolates and 78.4% of E. faecalis isolates were multidrug resistant (resistant to 3 or more antibiotic groups). The lack of vancomycin-resistant Enterococcus among the enterococci isolates was important for public health.
Investigation of antimicrobial resistance and extended spectrum beta- lactamase production in Escherichia coli isolates of equine feces origin
(Ankara Univ Press, 2016) Ornek, Gamze; Unal, Nilgun
In this study, it was aimed to investigate the existence of ESBL and determine the resistance against various antibiotics of E. coli strains isolated from feces examples obtained from racing and jumping horses. One hundred E. coli isolates (racing: 37, jumping: 63) were analysed with 16 antibiotics by using the disc diffusion method and ESBL existence by fenotypic confirmatory test. The antibiotic resistance prevalences were compared between racing and jumping groups of horses. The highest resistance was obtained against tetracycline in both groups with 81.1% (30) in racing horses and 20.6% (13) in jumping horses. ESBL production has been determined in only 6 isolates among 100 E. coli isolates and all 6 ESBL positive isolates were isolated from the racing horses. In conclusion, the resistance prevalences to various antibiotics in racing horses were higher than jumping horses and ESBL production in the isolates from jumping horses was determined. The contamination of these agents in ecosystem could cause a potential risk factor for public health.
Investigation of some toxins genes and methicillin resistance gene in Staphylococcus aureus isolates from cows with subclinical mastitis
(Ankara Univ Press, 2013) Unal, Nilgun
The aim of this study was to investigate the genes of some staphylococcal enterotoxins and Panton-Valentine leukocidin and methicillin resistance of Staphylococcus aureus strains isolated from subclinical bovine mastitis. In this study, 60 S. aureus isolates were used and the genes were detected by PCR. seg-sei, sej, sec and seh genes were detected in eight (13.33%) isolates, six (10.00%) isolates, four (6.67%) isolates and three (5.00%) isolates, respectively. Sixteen (26.67%) isolates were found to harbor one or more toxin genes. None of the investigated isolates harbored sea, seb, sed, see, and tsst genes, while four (6.6%) isolates and two (3.30%) isolates had Panton-Valentine leukocidin gene and mecA gene, respectively. As a conclusion, it was determined that S. aureus strains isolated from cows with subclinical mastitis could produce enterotoxin and harbor mecA gene. This situtiation could be a potential risk factor for public health.
A Single Clone Acinetobacter baumannii Outbreak in a State Hospital in Turkey
(Natl Inst Infectious Diseases, 2013) Cicek, Aysegul Copur; Karagoz, Alper; Koksal, Ersin; Erturk, Ayse; Ozgumus, Osman Birol; Koksal, Zeynep Senturk; Durmaz, Riza
Acinetobacter baumannii is an important pathogen in hospitalized patients, particularly those in the intensive care unit (ICU). A total of 21 A. baumannii (6 from 5 patients and 15 from environmental samples) were isolated in the ICU and the isolation room of a state hospital in June 2011. The possible source of the outbreak was investigated. A. baumannii isolates were identified using conventional biochemical tests, BBL Crystal Identification Systems, OXA-51 specific PCR, and 16S rDNA sequencing. All the isolates were multidrug-resistant, showing resistance to cephalosporins, carbapenems, fluoroquinolones, and the aminoglycoside group of antibiotics. Pulsed-field gel electrophoresis suggested that all A. baumannii isolates were derived from a common source.

Güncel Gönderiler