Suscetibilidade à azitromicina de isolados bacterianos de processos infecciosos em cães e gatos

Abstract

O presente estudo avaliou o perfil de suscetibilidade à azitromicina de patógenos bacterianos prevalentes em diferentes sítios infecciosos de animais de companhia. Adicionalmente, foram estudados o perfil de atividade in vitro de azitromicina contra esses patógenos e sua concentração inibitória mínima (CIM). Testes como a difusão em disco e a microdiluição em caldo detectaram resistência respectivamente em 48,6% e 55% dos isolados de Staphylococcus spp. e em 55,3% e 72,7% dos bastonetes Gram-negativos. A CIM50 para S. aureus foi 4,0mg/mL, para S. intermedius foi de 1,0mg/mL, para Staphylococcus spp. coagulase-negativas foi de e"512mg/mL e para bastonetes Gram-negativos foi de 256mg/mL. Quinze por cento (9/60) dos isolados oxacilina-resistente e multidroga-resistentes, mecA-positivos, de Staphylococcus spp. apresentaram também resistência à azitromicina. A disseminação de bactérias multidroga-resistentes aponta para a necessidade da avaliação da atividade antimicrobiana para selecionar o fármaco mais indicado e, assim, minimizar falhas terapêuticas na conduta clínica veterinária.

Multidrug-Resistant Bacterial Pathogens Assessment in Canine Ophthalmic Infections

“…In this study, of the 18 samples of Staphylococcus spp. 38.89% (7/18) were positive for detection of mecA gene in the PCR reaction, a value higher than found by Pereira et al (2009), 15%.…”

Antibiotic Resistance in Staphylococcus Species of Animal Origin

“…Pereira et al (2009) also evaluated the genetic markers of Staphylococcus spp azithromycin resistance by PCR technique and detected a 39% prevalence of erm genes, being ermC gene the most detected, showing a prevalence of 24% among all Staphylococcus isolates, followed by 12% ermA and 3% of ermB. No isolates were positive to mefA gene, what may support the theory about methylase ribossomal modification as the principal resistance mechanism associated to macrolide resistance among staphylococci.…”

“…Coagulase-negative staphylococci (CNS), which were traditionally considered to be minor infectious pathogens, have become more common (Huxley et al, 2002 (Lilenbaum et al, 2000;Pereira et al, 2009;Pyöräla et al, 2009;Soares et al, 2008).…”

“…Empirical antimicrobial chemotherapy without previous accomplishment of bacterial identification and antimicrobial susceptibility assays contributes to increase of antimicrobial resistance prevalence in pet animal reservoirs (Guardabassi et al, 2004;Morgan et al;. Pereira et al (2009) evaluated azithromycin resistance among 100 staphylococci isolates from pet animals infections. It was detected a percentual of resistant isolates of 54% to Staphylococcus intermedius, 67% of S. aureus, 38% of S. hyicus, 67% of coagulase-negative Staphylococcus spp through disc diffusion test.…”

“…Azithromycin have a remarkable application due to its superior pharmacokinetics properties and broad spectrum activity, including Gram-positive and negative bacteria species, intracellular pathogens and protozoan parasites . Pereira et al (2009) evaluated the resistance to azithromycin of 225 clinical samples from different infectious sites of pet animals in order to establish the benefits of introducing this drug in veterinary therapy in Brazil since it has already been used for human therapy. Azithromycin resistance can be caused by several mechanisms, such as target modification mediated by a 23S rRNA methylase, presence of efflux pumps and drug inactivation (Lim et al, 2002).…”