ABSTRACT
Antimicrobial Resistance (AMR) and Healthcare Associated Infections (HAIs) are major global public health challenges in our time. This study provides a broader and updated overview of AMR trends in surgical wards of Mulago National Referral Hospital (MNRH) between 2014 and 2018. Laboratory data on the antimicrobial susceptibility profiles of bacterial isolates from 428 patient samples were available. The most common samples were as follows: tracheal aspirates (36.5%), pus swabs (28.0%), and blood (20.6%). Klebsiella (21.7%), Acinetobacter (17.5%), and Staphylococcus species (12.4%) were the most common isolates. The resistance patterns for different antimicrobials were: penicillins (40-100%), cephalosporins (30-100%), ß-lactamase inhibitor combinations (70-100%), carbapenems (10-100%), polymyxin E (0-7%), aminoglycosides (50-100%), sulphonamides (80-100%), fluoroquinolones (40-70%), macrolides (40-100%), lincosamides (10-45%), phenicols (40-70%), nitrofurans (0-25%), and glycopeptide (0-20%). This study demonstrated a sustained increase in resistance among the most commonly used antibiotics in Uganda over the five-year study period. It implies ongoing hospital-based monitoring and surveillance of AMR patterns are needed to inform antibiotic prescribing, and to contribute to national and global AMR profiles. It also suggests continued emphasis on infection prevention and control practices (IPC), including antibiotic stewardship. Ultimately, laboratory capacity for timely bacteriological culture and sensitivity testing will provide a rational choice of antibiotics for HAI.
ABSTRACT
BACKGROUND: The increase in drug resistance to affordable antibiotics used to treat Gram positive bacterial infections has complicated the management of enterococcal infections. Resistance to vancomycin, one of the most powerful antibiotics, is of utmost concern as both intrinsic and acquired forms of resistance do occur in enterococci. This cross-sectional study aimed to determine the species, antibiotic susceptibility profiles and vanA/vanB gene frequencies among enterococci isolated from patients at Mulago Hospital in Kampala, Uganda. METHODS: Between November 2011 and October 2012, stool, urine, sputum and blood samples, as well as vaginal, endocervical, pus, ear and urethra swabs from 3229 patients were processed for isolation of bacteria, yielding 162 enterococci of which 115 were available for analysis (one isolate per specimen/patient). Species-level confirmation and susceptibility testing were determined with the Phoenix™ AST/ID Automated System, while vanA/vanB gene carriage was determined by PCR. RESULTS: Species-level identification revealed 72 isolates of E. faecalis, 20 E. gallinarum/casseliflavus, 5 E. faecium, 4 E. raffinosus and 2 isolates each for E. hirae and E. durans. Ten isolates could not be identified to species level. Antibiotic resistance was generally low especially to ampicillin, quinolones, nitrofurantoin, glycopeptides and linezolid, but high for erythromycin and tetracycline. Equally, vanA and vanB gene frequencies were low (i.e. 15.8 and 7.9%, respectively) and detected only in E. casseliflavus/gallinarum species that are intrinsically resistant to vancomycin. Vancomycin resistant isolates of E. faecalis and E. faecium were not detected. CONCLUSIONS: Enterococcus species are frequent in clinical specimens at Mulago Hospital but they are highly susceptible to common antibiotics especially ampicillin. While vancomycin resistant enterococcal (VRE) isolates of E. faecium and E. faecalis are rare in the hospital and frequency of multidrug resistance is low, non-faecium and non-faecalis VRE isolates (i.e. E. gallinarum/casseliflavus) are frequent, some with VanA/VanB (high-level) vancomycin resistance. Therefore, species-level identification of enterococci is necessary in resource limited settings to guide infection control and treatment of enterococcal infections.
