Frequency and antibiotic susceptibility of gram-positive bacteria in Makkah hospitals

Gram-positive bacteria are important nosocomial pathogens. The objective of this study was to estimate the frequencies and resistance rates of gram-positive pathogens isolated from hospitals in Makkah, Saudi Arabia.

Prospective study at three Makkah hospitals from May 2008 to April 2009.

Clinical isolates were collected and demographic and laboratory data were recorded. Standard microbiological methods were used to identify the organisms and test for antimicrobial susceptibility. The results were interpreted according to the Clinical Laboratory Standards Institute (CLSI) guidelines.

Clinical isolates were collected from 1087 patients. Gram-positive pathogens infected all age groups, but had no gender predominance. Staphylococcus aureus was the most common cause of wound infection and accounted for more than half of the clinical isolates (688 cases). Coagulase-negative staphylococcus (CONS) was a common isolate from blood cultures. Wounds were the most common site of infection (37.6%). Enterococcus spp. and Streptococcus agalactiae were the second most common bacteria (26%). The resistance rates of S aureus and CONS isolates were 39.4% and 82.4% for oxacillin, respectively. Among the streptococci, the resistance rates of Streptococcus pneumoniae were 21.1% and 16.7% for ampicillin and erythromycin, respectively.

S aureus infections were found to be very common in the Makkah hospitals. Infection prevention, control measures and continuous monitoring for antibiotic susceptibility are necessary to reduce these and other nosocomial infections.