Publication: Enfeksiyon etkeni bacteroides ızolatlarının protein sentezini inhibe eden antibiyotiklere karşı oluşan direncin fenotipik ve genotipik yönden araştırılması
Abstract
Amaç: Bu çalışmada Bacteroides fragilis grubu (BFG) bakterilerin klindamisin, tetrasiklin ve tigesikline direnç durumlarını saptamak, direnç oluşumundan sorumlu direnç genlerinin dağılımını belirlemek amaçlanmıştır.Yöntem: Hastanemizde Ocak 2017 ile Aralık 2018 tarihleri arasında, çeşitli klinik örneklerden izole edilen toplam 82 BFG izolatı MALDI-TOF MS ile tanımlanmış, antibiyotiklere duyarlılıkları Clinical and Laboratory Standards Institute (CLSI)’in önerdiği agarda dilüsyon yöntemi ile belirlenmiştir. Aynı izolatlarda, antibiyotik direnç genlerinden tetM, tetQ, tetX, tetX1, tet36, ve ermF varlığı PCR ile araştırılmıştır.Bulgular: Batın içi apsesi (n=36), dokudan biyopsi (n=16), kan (n=14) ve diğer steril vücut sıvıları (n=12) gibi çeşitli klinik örneklerden üretilen 82 BFG izolatı tür düzeyinde; Bacteroides fragilis (n=48), Bacteroides thetaiotaomicron (n=17), Bacteroides vulgatus (n=5), Bacteroides ovatus (n=4), Bacteroides caccae (n=1), Bacteroides uniformis (n=1) ve Parabacteroides distasonis (n=6) olarak tanımlanmıştır. İzolatların %54,9’u klindamisine, %84,1’i tetrasikline, %4,9’u tigesikline dirençli bulunmuş, tür düzeyinde irdelendiğinde B. fragilis suşlarına göre diğer BFG türlerinde direnç daha fazla saptanmıştır. Klindamisine dirençten sorumlu ermF geni, genel anlamda izolatların %57,3’ünde saptanmış, B. thetaiotaomicron türünde %70,6 ile en yüksek oranda bulunmuştur. tet gen pozitiflikleri %18,8’den %66,7’e değişen oranlarla türler arasında dağılım göstermiştir. Genel anlamda tetQ gen pozitifliği diğer tet genlerine göre daha fazla bulunmuştur. İzolatların %92,7’si en az bir antibiyotiğe dirençli, %94’ü ise en az bir direnç geni pozitif bulunmuştur.Sonuç; BFG izolatlarımızın klindamisin, tetrasiklin ve tigesikline direnç durumları ve direnç gelişiminde önemli role sahip direnç genlerine ait veri sağlanmıştır. Elde ettiğimiz bilgiler, yapmayı hedeflediğimiz BFG türleri içinde veya başka bakteriler arası direnç aktarımı çalışmalarına bir başlangıç oluşturması bakımından önemlidir.
Objective: Our aims were to determine the resistance of Bacteroides fragilis group (BFG) bacteria to clindamycin, tetracycline and tigecycline and establish the distribution of related resistance genes.Methods: In total 82 BFG strains, isolated from different clinical samples between January 2017-December 2018, were identified by MALDI-TOF MS. MICs of clindamycin, tetracycline and tigecycline were determined using agar dilution methodology according to Clinical and Laboratory Standards Institute (CLSI) guideline. The tetM, tetQ, tetX, tetX1, tet36, and ermF genes were detected by PCR.Results: BFG bacteria, isolated from clinical samples such as intra-abdominal abscess (n=36), tissue biopsy (n=16), blood (n=14) and other sterile body fluids (n=12), were identified at the species level as Bacteroides fragilis (n=48), Bacteroides thetaiotaomicron (n=17), Bacteroides vulgatus (n=5), Bacteroides ovatus (n=4), Bacteroides caccae (n=1), Bacteroides uniformis (n=1) and Parabacteroides distasonis (n=6). The resistance rates to clindamycin, tetracycline and tigecycline were 54,9%, 84,1%, 4,9%, respectively. Non-B. fragilis isolates were more resistant than B. fragilis strains. In total 57,3% of the isolates were the ermF gene positive, which was responsible for clindamycin resistance, B. thetaiotaomicron had the highest rate of resistance gene (70,6%). The tet gene positivity ranged from 18,8% to 66,7% among species. tetQ gene positivity was higher than other tet genes. 92,7% of the isolates were resistant to at least one antibiotic, 94% had at least one resistance gene.Conclusion: This study provided data on antimicrobial resistance of our BFG isolates to clindamycin, tetracycline and tigecycline and the related resistance genes. However, it could also be a starting point for the further investigation of the antibiotic resistance mechanisms of the Bacteroides species, as well as, resistance transfer among BFG isolates and to other bacteria.
Objective: Our aims were to determine the resistance of Bacteroides fragilis group (BFG) bacteria to clindamycin, tetracycline and tigecycline and establish the distribution of related resistance genes.Methods: In total 82 BFG strains, isolated from different clinical samples between January 2017-December 2018, were identified by MALDI-TOF MS. MICs of clindamycin, tetracycline and tigecycline were determined using agar dilution methodology according to Clinical and Laboratory Standards Institute (CLSI) guideline. The tetM, tetQ, tetX, tetX1, tet36, and ermF genes were detected by PCR.Results: BFG bacteria, isolated from clinical samples such as intra-abdominal abscess (n=36), tissue biopsy (n=16), blood (n=14) and other sterile body fluids (n=12), were identified at the species level as Bacteroides fragilis (n=48), Bacteroides thetaiotaomicron (n=17), Bacteroides vulgatus (n=5), Bacteroides ovatus (n=4), Bacteroides caccae (n=1), Bacteroides uniformis (n=1) and Parabacteroides distasonis (n=6). The resistance rates to clindamycin, tetracycline and tigecycline were 54,9%, 84,1%, 4,9%, respectively. Non-B. fragilis isolates were more resistant than B. fragilis strains. In total 57,3% of the isolates were the ermF gene positive, which was responsible for clindamycin resistance, B. thetaiotaomicron had the highest rate of resistance gene (70,6%). The tet gene positivity ranged from 18,8% to 66,7% among species. tetQ gene positivity was higher than other tet genes. 92,7% of the isolates were resistant to at least one antibiotic, 94% had at least one resistance gene.Conclusion: This study provided data on antimicrobial resistance of our BFG isolates to clindamycin, tetracycline and tigecycline and the related resistance genes. However, it could also be a starting point for the further investigation of the antibiotic resistance mechanisms of the Bacteroides species, as well as, resistance transfer among BFG isolates and to other bacteria.