Methicillin and Inducible Clindamycin-resistant Staphylococcus aureus Isolates from Clinical Samples in Abia State

Abstract

Staphylococcus aureus is a major bacterial pathogen that causes different community and hospital-acquired infections. S. aureus resistant to methicillin has become a big and expanding problem of concern in many developing countries. Clindamycin has also been discovered to be a preferred therapeutic alternative for the treatment of both methicillin susceptible and resistant staphylococcal infections. This study examined the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) in clinical samples of patients in Abia state, Nigeria using standard recommended procedures. A total of 750 clinical specimens of blood and urine samples, wound, ear, nasal, high vaginal and ear swabs were collected from three major health facilities in Abia state, Nigeria. Each sample was cultured for bacterial isolates and examined for colonial and cellular morphology while biochemical identification was performed. Antimicrobial susceptibility test was performed on Mueller-Hinton agar (MHA) by disc diffusion method and MRSA screening was done using cefoxitin disc. A total of 265 (35.3%) S. aureus isolates were recovered, out of which 126(47.5%) were from males and 139(52.5%) were from females, however there was no association between the prevalence and gender (p-value = 0.05) and also prevalence and age (p-value = 0.52). Of the 265 S. aureus isolates recovered, 164(61.9%) were MRSA. All 100% of the MRSA were susceptible to vancomycin, 120(73.2%) to clindamycin, 92(56.1%) to gentamycin. All 100% were resistant to ceftazidine, 157(95.7%) to cloxacillin, 146(89.0%) to augmentin, 136(82.9%) to ceftriaxone and 103(61.6%) to erythromycin. The MRSA strains showed much higher resistance rate than their MSSA counterparts to all tested antibiotic except clindamycin. 64(39.0%) of the MRSA were resistant to 4 classes of antibiotics indicating multi drug resistance (MDR). The overall prevalence of inducible clindamycin resistance among methicillin resistant isolates was 29(17.7%). This implies that 17.7% could have been misidentified as clindamycin susceptible by Kirby-Bauer disk diffusion method. In conclusion prevalence of MRSA was high and it is important to routinely carry out the D-test for detection of inducible clindamycin resistance if clindamycin is considered as a treatment option.

Inducible Clindamycin-Resistant Staphylococcus aureus Strains in Africa: A Systematic Review

“…Despite a 33.3% record of inducible clindamycin resistance in 2013, there has been a progressive drop in the prevalence of inducible clindamycin resistance since 2007 [ 17 ]. A similar 10.0% prevalence was observed in Egypt during 2017 and 2018 [ 23 , 27 ]. Generally, there were heterogeneous distribution and prevalence rate of inducible clindamycin resistance among S. aureus isolates in Africa according to the reviewed studies ( Figure 3 ).…”

“…Despite the lack of complete information on the resistance genes, investigations have shown that many S. aureus isolates coproduced resistance genes such as erm (A, B, C, E) genes, msrA genes, mphC genes, and lnuA genes. Among the recovered erm genes in Egypt, the ermC gene was a highly detected resistance gene, at 70.0% [ 23 ], followed by the ermA gene, with a 67.9% detection rate [ 21 ]. The msrA gene was also detected among S. aureus isolates, with a 70.0% high detection rate in Egypt [ 23 ].…”

“…Among the recovered erm genes in Egypt, the ermC gene was a highly detected resistance gene, at 70.0% [ 23 ], followed by the ermA gene, with a 67.9% detection rate [ 21 ]. The msrA gene was also detected among S. aureus isolates, with a 70.0% high detection rate in Egypt [ 23 ]. A study in Uganda also revealed ermC genes (32.7%) [ 17 ].…”

Phenotypic Detection of Methicillin and Inducible Clindamycin Resistant Staphylococcus Aureus: An Effort to Combat Antimicrobial Resistance and Improve Patient Safety in Gombe, Nigeria

“…The pattern of distribution of isolates among different specimens which revealed urine being the most frequent followed by swabs before seminal fluid, aspirates, and blood is a reflection of the frequency/predominance of these specimens in the laboratory requests. Similarly, several other studies have noted differences in pattern of distribution of isolates among different specimens (5,10,11,20). Variations in gender and age distribution did not also reveal any statistical significance probably due to similarities in habits/exposure with prevalence of the isolate among the different groups.…”

“…Although there were few reports on MDR Staphylococcus aureus from North Eastern Nigeria, virtually all the studies were carried about a decade ago and only on MRSA (12,13). Many other studies some of which also reported findings on inducible clindamycin resistance were from other parts of Nigeria (11). This study reported the prevalence and relationship of MRSA and inducible clindamycin resistance among clinical isolates of Staphylococcus aureus in Gombe Nigeria.…”