In this study, we report the frequencies of drug resistance of the key bacterial pathogens using the routine results of 5 major centers, that give a considerable representation the Syrian population.
This is the first large, geographically-comprehensive, pathogen-comprehensive study about antimicrobial resistance in Syria.
We notice an extremely high rate of antimicrobial resistance among all the species studied, for most studied antibiotics.
It is important to notice that Acinetobacter spp. Resistance rate was 100% for Amoxicillin- clavulinic acid, cefadroxil, cefotaxime, and tetracyclin. Resistance rate to the tested antibiotics was more than 70%, except for cotrimoxazole (36%) and Colistin (6%), making Colistin the most in-vitro effective for Acinetobacter spp. In Syria, followed by cotrimoxazole.
Cephalosporins have an extremely high rate of resistance, especially in G- bacteria. For example, 77% of E.coli, 73% of Klebsiella and 82% of pseudomonas are resistant for ceftriaxone, a widely used antibiotic for all kinds of infections in Syria. However, Ceftriaxone with sulbactam has lower resistance rates but these rates are still high (table1).
The effect of macrolides on G- bacteria is minimal. 87% and 100% of E.coli strains are resistant to azithromycin and erythromycin, respectively. 86% and 100% of Klebsiella spp. strains are resistant to azithromycin and erythromycin, respectively.
Fortunately, G+ bacteria still have a proportionally low resistance rate to vancomycin. Linezolid is still effective too (table 1). However, resistance rate to linezolid was 23% in streptococcus pyogens and 20% in streptococcus pneumoniae.
Unfortunately, 54% of staphylococcus aureus and 38% of streptococcus pyogens are resistant to amoxicillin with clavulanic acid.
We notice an extremely high rates of resistance to nitrofurantoin among urinary tract infection-related species. For example, 45% of E.coli, 60% of Enterobacter, 79% of Kleibsella, 100% of proteus and 79% of Pseudomonas isolates are resistant to Nitrofurantoin.
Salmonella typhi, a key pathogen in the developing countries, has a high resistance rates to the studied antibiotics, including ciprofloxacin (25%). However, piperacillin with tazobactam and cefepime have the least resistance rate: 13% for piperacillin with tazobactam and 20% for cefepime.
It is worthy to note that resistance rates to Colistin are minimal.
A quick look at table 1 reveals that most bacteria, especially E.coli spp., Enterobacter spp., Klebsiella, Pseudomonas spp. And staphylococcus aureus Have become “superbugs” in Syria.
To better understand the impact of the Syrian war on antimicrobial resistance, we should compare the current data with the pre-conflict data. For example, Al-Omar reported in that the prevalence of Staphylococcus aureus resistance to ampicillin in Misiaf (Tartous Countryside) during 2004 is 69%, and to amoxicillin–Clavulanate is 37% (7), while we found in our study that the prevalence of Staphylococcus aureus resistance to ampicillin is 92%, and to amoxicillin–Clavulanate is 54%.
Obied and Obied in 2005 found that 64% of Streptococcus pneumonia strains in Damascus isolated from CSF were resistant to penicillin, 16% to erythromycin, and 16% to tetracycline, and None resistant to ceftriaxone, cefotaxime, amoxicillin–Clavulanate (8), While we found in our study that that 64% of Streptococcus pneumonia strains were resistant to penicillin, 78% to erythromycin, and 35% to tetracycline, and 10% resistant to ceftriaxone, 15% resistant to cefotaxime and 23% amoxicillin–Clavulanate.
Hussein and Nizzam studied the antimicrobial resistance of bacteria isolated from Otitis media in children of Qamishli in North-eastern Syria, during 2008 and 2009 (9). 0% of Pseudomonas spp. and staphylococcus aureus isolates were resistant for imipenem, but in the current study 41% of Pseudomonas and 15% of Staphylococcus aureus isolates were resistant to Imipenem. In the same study 31% of Pseudomonas isolates and 20% of Klebsiella isolates were resistant to levofloxacin, while in our study 62% of Pseudomonas isolates and 63% of Kleibsella isolates were resistant to levofloxacin
Hamzeh et al. conducted a retrospective review of 260 Acinetobacter baumannii isolates from 2008 to 2011 in Aleppo (10). Resistance to specific antibiotics in the latter study was: 65% imipenem, 87% piperacillin– tazobactam,74% cotrimoxazole, 7% Colistin. In our study, Resistance of Acinetobacter spp. strains to the same antibiotics was: 83% imipenem, 82% piperacillin– tazobactam, 36% cotrimoxazole, 6% Colistin. These were just examples of the dramatic growing of the antimicrobial resistance in Syria.
The main reasons for this antimicrobial resistance trend in Syria is the irrational use of antibiotics in Syria. Antibiotics are easily available for people without prescription (11). In addition, the Syrian people do not have enough awareness of antimicrobials use (12)(13). Also, the lack of the diagnostic tests during war urged healthcare providers to treat infections arbitrarily using wide spectrum antibiotics.
During war, healthcare services are damaged, sanitation is poor, health professionals migrate, and exposure in compromised healthcare centers is dramatically increased. War further disrupts the administrative bodies that regularly tackle the drivers of AMR (6).
Although Abbara et al. (6) provided a comprehensive review of the existing evidence of antimicrobial resistance in the Syria, We found by electronic search some additional publications that address antimicrobial resistance state in Syria before and after war (9) (15) (16) (17) (18) (19) (20). We mentioned them to make future researchers aware of them. However, an extensive hand-search should be held if we wanted to do a systematic review about antimicrobial resistance in Syria, as most Syrian journals are not indexed in databases, and much research projects in the universities are not published in journals, but indexed in the university library.
This study has major limitations. some valuable information was incomplete, such as: sample type, clinical complaint, wards where the patients were hospitalized in, gender and age of the patients. therefore, we decided to analyze the variables for which we had complete information. In addition, some important bacteria are not included in our study like anaerobes, Shigella, H.pylori,…etc, because : They are usually diagnosed clinically and treated arbitrarily and they need special media and conditions that are not available in our labs, especially during war. In General, there is a lack in the literature reporting the antimicrobial resistance in Syria before and after war, especially fastidious organisms like H.pylori. Another limitation is that much antibiotics are not reported sufficiently, because of the limited availability during war. We have experienced the significant disadvantages of the use of routine results, and of the multi-centric design.