In 2014, the WHO [22] had expressed the need to establish a global surveillance system for antimicrobial resistance, then launched in October 2015, the Global Antimicrobial Surveillance System (GLASS), in close collaboration with various existing networks based on experience from other WHO surveillance programs. This study aimed to contribute to such a need. The results identified 12 bacterial strains were in the samples taken from 758 cultures, mainly the EC strain. The profiles found here are comparable to those reported in other studies in Africa, the USA, and Europe [24], as illustrated below. Some isolates might even be XDR bacteria, but we did not separate them because the data did not come from a controlled study. The GLASS report [22] revealed that the most common MDR bacteria were Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pneumoniae, followed by Salmonella spp. The 29.4% median rate of MDR strains found in Bukavu ranges between 23% in the USA and 37% in India. In the USA, a study [24] conducted in community hospitals revealed 23% of MDR pathogens, of which the three most common were SA(28%), EC(24%), and coagulase-negative staphylococci (10%); the infecting organism varied according to the place of acquisition. In Rwanda, the prevalence of MDR strains was 28% based on three primary data [26]. Studies in India found 37.1% MDR bacteria, 13.8% XDR and 0% PDR [2, 25]. Despite the differences in the prevalence levels reported worldwide, the results support the alert on the increase in MDR bacteria around the world.
Aggregation of results by the hospital showed that more cases were from GHP (53.8%), followed by HBP (30.9%) and CSL (15.2%). The significant difference (p = 0.001) is only related to the size of each hospital. The profile also indicated that most isolates were from sexually transmitted UTIs (61.8%) followed by skin infections (23.8%). The majority of people carrying MDR strains were adults (60%), as expected since children are less prone to UTIs. The high percentage of women (51%) is due to anatomical causes (proximity to the vaginal and anal openings), poor hygiene habits, sexual intercourse, and pregnancy [17, 23].
The susceptibility profiles of the strains varied according to the classes of antibiotics. Regarding resistance to the beta-lactam category, the case of ampicillin and amoxicillin is striking. The test shows that these drugs are less effective against almost all strains. Many bacteria are also resistant to cephalosporins in this study. However, our previous research had shown that they are currently still widely prescribed and also used as self-medication in Bukavu [17, 18]. A review article [16] reports that MDR (penicillin + two other classes) is 25% in Africa, 20% in Latin America, 12% in Eastern Europe, 18% in Western Europe, and 26 % in the USA. Data from bacterial resistance surveillance networks show that the distribution of 3rd generation cephalosporin-resistant Enterobacteriaceae species has increased significantly [22, 27]. According to the authors, this resistance mainly concerns the production of extended-spectrum beta-lactamase (ESBL) and, to a lesser extent, plasma cephalosporinases (AmpC). For instance, the resistance of KP to third-generation cephalosporin is critical on a large scale in all WHO regions of the Americas, the Western Pacific, the Eastern Mediterranean, and the European Region [22]. Community-based infection with resistant E.coli producing extended-spectrum beta-lactamases is ubiquitous in Asia, the Middle East, South America, and parts of Europe [28].
Regarding aminoglycosides (AGs), gentamicin was more effective against EC (60%), resistant to PA, KP, and Salmonella. However, it is used mainly in combination with amoxicillin and azithromycin [18]. In the study by Bala et al. [29], no MDR isolate of gentamicin appeared. These in vitro results suggest that gentamicin may be an effective treatment option for MDR strains. In Bukavu hospitals, gentamicin is used mainly in combination with amoxicillin and azithromycin [18]. Parenteral administration of AGs, which limits their use as self-medication, partly explains their preserved efficacy. By far, the most common mechanism of resistance to AGs is the inactivation of these antibiotics by enzymes modifying their structure [30, 31].
This study showed high resistance of many infections to second-generation quinolones. Only 25% of the 76 EC strains were susceptible to ciprofloxacin, which backs what some studies reported in Asia and Africa [16, 22, 32–34]. EC ST131 is a clone of MDR disseminated worldwide that presents resistance to fluoroquinolones in addition to the production of ESBL CTX-M. EC ST131 strains tend to induce pyogenic liver abscesses and sometimes metastatic infections, including meningitis. The median resistance of SE Typhi to nalidixic acid is between 15.4–43.2% for pathogens isolated from patients with severe illness [28, 35–37].
Finally, the percentage of strains susceptible to meropenem was 41% for EC, 66.7% for SP, and less than 25% for the others, consistent with other studies. However, most clinicians consider carbapenems to be the class of choice for severe infections caused by ESBL-producing Enterobacteriaceae [34, 35]. Carbapenems-resistance of PA is the most typical and frequent example of resistance induced by developing cell membrane impermeability [38]. Furthermore, the enzymatic inactivation of carbapenems is the most common resistance mechanism in A. Baumannii [32]. Carbapenem-resistant Enterobacteriaceae (CRE) represents an immediate threat to public health that requires urgent and aggressive action. Community-wide infections are likely to lead to a dramatic increase in the practical use of carbapenems [39, 40]. A review article reported that the median prevalence of resistance to chloramphenicol in Enterobacteriaceae, isolated from patients with febrile illness, ranged from 31.0–94.2%.