In vitro efficacy of fosfomycin against clinical strains

Abstract

Objectives: Fosfomycin is an alternative drug for treatment of uncomplicated urinary tract infections. This study aimed to investigate in vitro activity of fosfomycin against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase negative staphylococci (MRCoNS), vancomycin-resistant Enterococcus faecium (VR E. faecium), Escherichia coli, Klebsiella pneumoniae, and Enterobacter isolates. Methods: Clinical isolates of MRSA, MRCoNS, E. coli, K. pneumoniae and Enterobacter spp. and VRE isolates which were isolated from rectal swaps were identified with Vitek 2 Compact (Biomeriux, France) and BD Phoenix (BD USA) automated systems. The Kirby-Bauer disc diffusion method was used to determine the susceptibility to fosfomycin. Results: All the MRSA (n=40), MRCoNS (n=40), and VR E. faecium (n=62) isolates were susceptible to fosfomycin. The fosfomycin susceptibility rates for E. coli, K. pneumoniae, and Enterobacter spp. were 97.5% (39 of 40), 97.3% (36 of 37), and 86.9% (20 of 23), respectively. One (2.7%) isolate of K. pneumoniae and three (13.1%) isolates of Enterobacter spp. showed intermediate susceptibility to fosfomycin. Resistance to fosfomycin was detected in only one (2.5%) isolate of E. coli. Conclusion: Based on the results of our study, fosfomycin is highly active against a collection of several gram-positive and gram-negative bacteria, including multidrug resistant isolates, and is an alternative drug in the treatment option.

Keywords

• Fosfomycin, gram-positive bacteria, gram-negative bacteria, antimicrobial agent

In vitro efficacy of fosfomycin against clinical strains

Öz

Amaç: Fosfomisin komplike olmayan üriner sistem enfeksiyonlarının tedavisinde alternative bir ilaçtır. Bu çalışmanın amacı fosfomisinin in vitro etkinliğini, metisiline dirençli Staphylococcus aureus (MRSA), metisiline dirençli koagülaz negatif stafilokoklar (MRKNS), vankomisine dirençli Enterococcus faecium (VR- E. faecium), Escherichia coli, Klebsiella pneumoniae ve Enterobacter izolatlarında araştırmaktır. Yöntemler: MRSA, MRKNS, E. coli, K. pneumoniae ve Enterobacter spp. klinik örnekleri ve rektal sürüntüden izole edilen VRE izolatlarının tanımlanması Vitek2 Compact (Biomeriux, Fransa) ve Phoenix (BD, ABD) otomatize sisteminlerinde yapıldı. Fosfomisin duyarlılığı belirlenmesinde Kirby-Bauer disk difüzyon yöntemi kullanıldı. Bulgular: Tüm MRSA (n=40), MRKNS (n=40) ve VR- E. faecium (n=62) suşları fosfomisine duyarlı olarak saptandı. E. coli, K. pneumoniae ve Enterobacter spp. için fosfomisin duyarlılık oranları sırasıyla; % 97,5 (40’da 39), % 97,3 (37’de 36), % 86,9 (23’te 20) olarak bulundu. Bir K. pneumoniae izolatı (% 2,7) ve üç Enterobacter spp. izolatı (% 13,1) fosfomisine ortaduyarlı olarak saptandı. Fosfomisine karşı direnç sadece bir E. coli izolatında (% 2,5) saptandı.Sonuçlar: Fosfomisin çoklu ilaç direncine sahip izolatlar dahil birçok Gram pozitif ve Gram negatif bakteriye karşı invitro yüksek etkinliğe sahiptir ve alternatif bir tedavi seçeneği olarak kullanılabilir

Anahtar Kelimeler

• Fosfomisin, gram pozitif bakteri, gram negatif bakteri, antimikrobiyal ajan

Kaynakça

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