Antibiotic Susceptibility, Biofilm Production, and Detection of mecA Gene among Staphylococcus aureus Isolates from Different Clinical Specimens

Abstract

The increasing incidence of methicillin-resistant and biofilm-forming S. aureus isolates in hospital settings is a gruesome concern today. The main objectives of this study were to determine the burden of S. aureus in clinical samples, assess their antibiotic susceptibility pattern and detect biofilm formation and mecA gene in them. A total of 1968 different clinical specimens were processed to isolate S. aureus following standard microbiological procedures. Antibiotic susceptibility test of the isolates was performed by Kirby–Bauer disc-diffusion method following CLSI guidelines. Biofilm was detected through tissue culture plate method. Methicillin-resistant S. aureus (MRSA) isolates were screened using cefoxitin (30 µg) discs and mecA gene was amplified by conventional polymerase chain reaction (PCR). Of 177 bacterial growth, the prevalence of S. aureus was 15.3% (n = 27). MRSA were 55.6% (15/27) and 44% (12/27) exhibited multidrug resistance (MDR). There was no significant association between methicillin resistance and MDR (p > 0.05). Both MRSA and MSSA were least sensitive to penicillin (100%, 75%) followed by erythromycin (86.6%, 66.6%). Most of the MRSA (93.4%) were susceptible to tetracycline. All S. aureus isolates were biofilm producers—19 (70%) were weak and only one (4%) was a strong biofilm producer. The strong biofilm-producing MSSA was resistant to most of the antibiotics except cefoxitin and clindamycin. None of the MSSA possessed mecA gene while 8 (53.3%) MRSA had it. More than half of S. aureus isolated were MRSA. High incidence of multidrug resistance along with capacity to form biofilm among clinical isolates of S.aureus is a matter of apprehension and prompt adoption of biosafety measures is suggested to curb their dissemination in the hospital environments.

Biofilm Formation of Staphylococcus aureus from Pets, Livestock, and Wild Animals: Relationship with Clonal Lineages and Antimicrobial Resistance

“…Gaire et al, reported that most isolates susceptible to ciprofloxacin, gentamycin, clindamycin and cefoxitin were weak biofilm producers. In contrast, in the same study, it was reported that most isolates resistant to penicillin and erythromycin produced weak biofilms [ 66 ]. In contrast to our results, Sun et al, showed that isolates resistant to tetracycline were stronger biofilm producers than susceptible isolates [ 67 ].…”

Antibiogram and detection of mecA gene among MRSA at Specialist Hospital Sokoto

“…Multidrug resistant S.aureus was found to be present in 85.5% of the cases. This is in contrast to the 44% stated by [24]. Antibiotic usage is driving the evolution of resistance [25].…”

“…As a result, the greater prevalence of MDR could be attributable to antibiotic overuse and abuse, which is frequent in Sokoto, Nigeria. Many phenotypic methods to detect MRSA have been developed but they are slow and vary in sensitivity and specificity [27] [24] (Gaire et al 2021) in which 36.5% and 53% were mecA positive respectively. Our result is lower compared to a report by [30] Hadyeh et al 2019, [31] McTavish et al 2019 who reported 95% mecA positive.…”

Studies Regarding the Antibacterial Effect of Plant Extracts Obtained from Epilobium parviflorum Schreb

“…They were sown in Mueller-Hinton and Columbia culture medium (Bio-Merieux, Craponne, France). The bacterial suspension used corresponded to a concentration of 10 7 colonies per training unit/mL micro-test, which correspond to a turbidity of the 0.5 Mac Farland tube (Figures 5 and 6) [30]. The Kirby-Bauer test for antibiotic susceptibility, known as the disc diffusion test, is a standard that has been used for years.…”