Species and drug susceptibility profiles of staphylococci isolated from healthy children in Eastern Uganda.

Staphylococci are a key component of the human microbiota, and they mainly colonize the skin and anterior nares. However, they can cause infection in hospitalized patients and healthy individuals in the community. Although majority of the Staphylococcus aureus strains are coagulase-positive, some do not produce coagulase, and the isolation of coagulase-positive non-S. aureus isolates in humans is increasingly being reported. Therefore, sound knowledge of the species and characteristics of staphylococci in a given setting is important, especially isolates from children and immunocompromised individuals. The spectrum of Staphylococcus species colonizing children in Uganda is poorly understood; here, we aimed to determine the species and characteristics of staphylococci isolated from children in Eastern Uganda. Seven hundred and sixty four healthy children less than 5 years residing in Iganga and Mayuge districts in Eastern Uganda were enrolled. A total of 513 staphylococci belonging to 13 species were isolated from 485 children (63.5%, 485/764), with S. aureus being the dominant species (37.6%, 193/513) followed by S. epidermidis (25.5%, 131/513), S. haemolyticus (2.3%, 12/513), S. hominis (0.8%, 4/513) and S. haemolyticus/lugdunensis (0.58%, 3/513). Twenty four (4.95%, 24/485) children were co-colonized by two or more Staphylococcus species. With the exception of penicillin, antimicrobial resistance (AMR) rates were low; all isolates were susceptible to vancomycin, teicoplanin, linezolid and daptomycin. The prevalence of methicillin resistance was 23.8% (122/513) and it was highest in S. haemolyticus (66.7%, 8/12) followed by S. aureus (28.5%, 55/193) and S. epidermidis (23.7%, 31/131). The prevalence of multidrug resistance was 20.3% (104/513), and 59% (72/122) of methicillin resistant staphylococci were multidrug resistant. Four methicillin susceptible S. aureus isolates and a methicillin resistant S. scuiri isolate were mupirocin resistant (high-level). The most frequent AMR genes were mecA, vanA, ant(4')-Ia, and aac(6')-Ie- aph(2'')-Ia, pointing to presence of AMR drivers in the community

Source-tracking ESBL-producing bacteria at the maternity ward of Mulago hospital, Uganda.

IntroductionEscherichia coli, Klebsiella pneumoniae and Enterobacter (EKE) are the leading cause of mortality and morbidity in neonates in Africa. The management of EKE infections remains challenging given the global emergence of carbapenem resistance in Gram-negative bacteria. This study aimed to investigate the source of EKE organisms for neonates in the maternity environment of a national referral hospital in Uganda, by examining the phenotypic and molecular characteristics of isolates from mothers, neonates, and maternity ward.MethodsFrom August 2015 to August 2016, we conducted a cross-sectional study of pregnant women admitted for elective surgical delivery at Mulago hospital in Kampala, Uganda; we sampled (nose, armpit, groin) 137 pregnant women and their newborns (n = 137), as well as health workers (n = 67) and inanimate objects (n = 70 -beds, ventilator tubes, sinks, toilets, door-handles) in the maternity ward. Samples (swabs) were cultured for growth of EKE bacteria and isolates phenotypically/molecularly investigated for antibiotic sensitivity, as well as β-lactamase and carbapenemase activity. To infer relationships among the EKE isolates, spatial cluster analysis of phenotypic and genotypic susceptibility characteristics was done using the Ridom server.ResultsGram-negative bacteria were isolated from 21 mothers (15%), 15 neonates (11%), 2 health workers (3%), and 13 inanimate objects (19%); a total of 131 Gram-negative isolates were identified of which 104 were EKE bacteria i.e., 23 (22%) E. coli, 50 (48%) K. pneumoniae, and 31 (30%) Enterobacter. Carbapenems were the most effective antibiotics as 89% (93/104) of the isolates were susceptible to meropenem; however, multidrug resistance was prevalent i.e., 61% (63/104). Furthermore, carbapenemase production and carbapenemase gene prevalence were low; 10% (10/104) and 6% (6/104), respectively. Extended spectrum β-lactamase (ESBL) production occurred in 37 (36%) isolates though 61 (59%) carried ESBL-encoding genes, mainly blaCTX-M (93%, 57/61) implying that blaCTX-M is the ideal gene for tracking ESBL-mediated resistance at Mulago. Additionally, spatial cluster analysis revealed isolates from mothers, new-borns, health workers, and environment with similar phenotypic/genotypic characteristics, suggesting transmission of multidrug-resistant EKE to new-borns.ConclusionOur study shows evidence of transmission of drug resistant EKE bacteria in the maternity ward of Mulago hospital, and the dynamics in the ward are more likely to be responsible for transmission but not individual mother characteristics. The high prevalence of drug resistance genes highlights the need for more effective infection prevention/control measures and antimicrobial stewardship programs to reduce spread of drug-resistant bacteria in the hospital, and improve patient outcomes

Prevalence and Antimicrobial Susceptibility Patterns of Bacteria from Milkmen and Cows with Clinical Mastitis in and around Kampala, Uganda

<div><p>Background</p><p>Identification of pathogens associated with bovine mastitis is helpful in treatment and management decisions. However, such data from sub-Saharan Africa is scarce. Here we describe the distribution and antimicrobial susceptibility patterns of bacteria from cows with clinical mastitis in Kampala, Uganda. Due to high concern of zoonotic infections, isolates from milkmen are also described.</p><p>Methodology/Principal Findings</p><p>Ninety seven milk samples from cows with clinical mastitis and 31 nasal swabs from milkmen were collected (one sample per cow/human). Fifty eight (60%) Gram-positive isolates namely Staphylococci (21), Enterococci (16), Streptococci (13), Lactococci (5), Micrococci (2) and Arcanobacteria (1) were detected in cows; only one grew <i>Staphylococcus aureus</i>. Furthermore, 24 (25%) coliforms namely <i>Escherichia coli</i> (12), <i>Klebsiella oxytoca</i> (5), <i>Proteus vulgaris</i> (2), <i>Serratia</i> (2), <i>Citrobacter</i> (1), <i>Cedecea</i> (1) and <i>Leclercia</i> (1) were identified. From humans, 24 Gram-positive bacteria grew, of which 11 were Staphylococci (35%) including four <i>Staphylococcus aureus</i>. Upon susceptibility testing, methicillin-resistant coagulase-negative staphylococci (CoNS) were prevalent; 57%, 12/21 in cows and 64%, 7/11 in humans. However, methicillin-resistant <i>Staphylococcus aureus</i> was not detected. Furthermore, methicillin and vancomycin resistant CoNS were detected in cows (<i>Staphylococcus hominis</i>, <i>Staphylococcus lugdunensis</i>) and humans (<i>Staphylococcus scuiri</i>). Also, vancomycin and daptomycin resistant Enterococci (<i>Enterococcus faecalis</i> and <i>Enterococcus faecium,</i> respectively) were detected in cows. Coliforms were less resistant with three pan-susceptible isolates. However, multidrug resistant <i>Klebsiella</i>, <i>Proteus</i>, <i>Serratia, Cedecea</i>, and <i>Citrobacter</i> were detected. Lastly, similar species grew from human and bovine samples but on genotyping, the isolates were found to be different. Interestingly, human and bovine <i>Staphylococcus aureus</i> were genetically similar (spa-CC435, spa-type t645 corresponding to ST121) but with different susceptibility patterns.</p><p>Conclusions/Significance</p><p>CoNS, Enterococci, Streptococci, and <i>Escherichia coli</i> are the predominant pathogens associated with clinical bovine-mastitis in Kampala, Uganda. Multidrug resistant bacteria are also prevalent. While similar species occurred in humans and cows, transmission was not detected.</p></div

Distinct patterns among staphylococci (panel A), enterococci (panel B) and streptococci (panel C) following RAPD genotyping.

<p>One isolate per lane.</p

Antimicrobial resistance among staphylococci from cows (panel A) and milkmen (panel B).

<p>Details in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063413#pone.0063413.s001" target="_blank">Tables S1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0063413#pone.0063413.s002" target="_blank">S2</a>.</p

Antimicrobial resistance patterns among coliforms (n = 24).

<p>AMP, Ampicillin; AMO; Amoxicillin-Clavulanate; SXT, trimethopprim-sulfamethoxazole; COL, Colistin; IMP, imipenem; CEF, Cefoxitine; CFT, Cefotaxim; CEP, Cephalothin; CFU, Cefuroxime; CFP, Cefepime; AZT, Aztreonam; ERY, Erythromycin; NTR, Nitrofurantoin; PIP, Piperacillin-Tazobactum; ERT, Ertapenem.</p><p>In boldface type are isolates found to be multi-drug resistant (MDR).</p