Prevalence of methicillin-resistant <i>Staphylococcus aureus</i> and extended spectrum β–lactamase producers among bacteria isolated from infected wounds in a tertiary hospital in Ibadan City

Abstract

Wound colonization by microorganisms is most frequently polymicrobial and incidences of high level resistance among bacterial isolates from wounds have been reported. Methicillin-resistant Staphylococcus aureus (MRSA) and extendedspectrum beta-lactamase (ESBL) producing Gram-negative bacteria both constitute serious challenge to physician in their choice of antibiotic treatment of infections caused by these bacteria. This study determined the antibiotic susceptibility profiles and prevalence of MRSA and ESBL producers among wound bacterial isolates from a tertiary hospital in Ibadan City. Forty (40) clinical bacterial isolates from five wound sources were collected from the Microbiology unit of the University College Hospital (UCH), Ibadan and were authenticated with standard bacteriological techniques. Antibiotic susceptibility test was done by disc-diffusion method using 19 antibiotics belonging to 12 classes. MRSA strains were detected by their resistance to cefoxitin and/or oxacillin antibiotics. Presumptive ESBL production was by double-disc synergy test using 30 µg cefotaxime and ceftazidime around 20/10 µg amoxicillin-clavulanic acid discs. ESBL confirmation was by minimum inhibitory concentration (MIC) using agar-dilution method. The authenticated isolates include Proteus spp (47.5%), Staphylococcus aureus (27.5%), Pseudomonas aeruginosa (12.5%), Klebsiella spp (7.5%), Acinetobacter baumanii (2.5%) and E. coli (2.5%). Distribution of the isolates collected according to wound sources includes: acute soft tissue wounds (35%), leg ulcer (32.5%), surgical wounds (17.5%), burn wounds (12.5%) and diabetic foot ulcer (2.5%). Distributions according to patients' gender are: male (65%), female (35%), and according to age-groups are: 0-19 years (22.5%), 20-39 years (35%), 40-59 years (32.5%) and ≥ 60 years (10%). All (100%) the isolates were multidrug resistant (MDR) being resistant to ≥ 3 classes of antibiotics. Percentages of isolates resistance to each of the antibiotic include: piperacillin, piperacillin-tozobactam and amoxicillin-clavulanic acid were 100%, ceftazidime, cefuroxime, cefixime, aztreonam, sulphamethoxazole-trimethoprim, erythromycin, chloramphenicol and doxycyclin were > 70%, cefoxitin (62.5%), Nitrofurantion (52.5%), ciprofloxacin (45%), ofloxacin (35%), perfloxacin (37.5%), gentamicin (32.5%) and imipenem (2.5%). Of the 11 Staphylococcus aureus collected, 54.5% were detected to be MRSA strains while ESBL production was detected in 55.2% of the Gram negative isolates. This study revealed 100% MDR phenotype constituting high level of MRSA strains (54.5%) and ESBL producers (55.2%) among Gram-positive and Gram-negative bacterial wound isolates respectively. Hence, this calls for caution in the use of extended spectrum antibiotics in treating patients with infected wounds.

Bacterial profiles, antibiotic susceptibility patterns, and associated factors of symptomatic urinary tract infections among symptomatic university students at Haramaya University, Eastern Ethiopia: Cross-sectional study

“…[3] However, the current study MDR result is lower than the study done in Ethiopia and Nigeria (81%-100%). [38][39][40] In contrast, the result of this study was higher than other documented results in Ethiopia (59.8%). [41] The high prevalence of MDR in the present study could also be due to various factors.…”

Detection of antibiotic resistance genes among multiple drug resistant Pseudomonas aeruginosa strains isolated from clinical sources in selected health institutions in Kwara State.

“…Pseudomonas aeruginosa is commonly implicated as a cause of health care acquired infections with high mortality rates (19). High rate of microbial resistance to the cephalosporins among the P. aeruginosa isolates was observed in this study.…”

Co-Production of Extended-Spectrum Beta-Lactamases and Metallo Beta-Lactamases Among Multi-Drug Resistant Gram-Negative Bacteria Isolates Collected From Tertiary Hospitals in Oyo State, Nigeria

“…While it has been well established that the narrow and some of the broad-spectrum classes of these group of antibiotics are now mostly ineffective clinically due to the emergence of the conventional beta-lactamases (i.e. the class of enzymes that inactivates the narrow spectrum antibiotics), the extended-spectrum beta-lactam antibiotics, such as the third generation cephalosporins (cefotaxime, ceftazidime, ceftriaxone) and the monobactams (aztreonam), developed to overcome the resistance conferred by the conventional beta-lactamases are gradually becoming less effective against most bacterial pathogens due to the advent of superior beta-lactamases known as extended-spectrum betalactamases (ESBLs) that hydrolyses the beta-lactam ring structure of the antibiotics (Alabi et al, 2016). The carbapenems, which were beta-lactam antibiotics of last resort commonly used in the treatment of the extended-spectrum beta-lactamase (ESBL) producing bacteria pathogens are also gradually becoming ineffective against some of these pathogens due to the development of a more superior betalactamases generally named carbapenemases part of which are the metallo beta-lactamases (MBLs) (Gaude and Hattiholli, 2013;Worthington and Melander, 2013;Levashov, 2014, Balsalobre et al, 2019, Mirza et al, 2019.…”