A retrospective study of antibiotic resistance patterns of bacterial pathogens isolated from patients in two Lebanese hospitals for two consecutive years (2018 and 2019)

Background: Misuse of antibiotics is the leading factor promoting emergence of bacterial resistance, a situation that has become a serious public health challenge. Among the leading bacteria that have developed resistance to antibiotics are Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, which have caused infections in patients, resulting in considerable mortality. The objective of this retrospective study was to assess antibiotic resistance rates of bacterial pathogens isolated from clinical specimens in two Lebanese hospitals between the years 2018 and 2019. Methodology: Bacteria isolated from routine clinical specimens collected from hospitalized patients in two hospitals, Haroun and Bekaa, in Lebanon for 2018 and 2019, were analyzed. Bacteria isolation and identification were carried out at the laboratory of each hospital using conventional microbiological methods. Antimicrobial susceptibility testings (AST) of each bacterial isolate to antibiotics were performed by the disc diffusion test and interpreted using EUCAST, CLSI or WHO/AST guidelines. Comparisons of the mean resistance rates of each isolate to individual antibiotics by year of isolation were done using the Z-test and p< 0.05 was considered statistically significant. Results: There were a total of 1698 bacteria isolates recovered from hospitalized patients in the two hospitals for 2018 and 2019, of which 87.5% were Gram-negative and 12.5% were Gram-positive bacteria. The most frequent among the Gram-negative isolates was E. coli (66.1%) followed by P. aeruginosa (13.3%), K. pneumoniae (7.7%), Proteus mirabilis (6.7%) and Enterobacter spp (6.3%), while coagulase positive staphylococci CoPS (68.4%) and E. faecalis (31.6%) were the two Gram positive isolates. Of the Gram-negative isolates over the two-year period, 72.2% of E. coli and 76.3% of K. pneumoniae were resistant to ceftazidime, 93% of P. mirabilis to colistin, and 98% of Enterobacter to cefoxitin, but low resistance rates were demonstrated by E. coli to imipenem (1%), K. pneumoniae to tigecycline and amikacin (0.9%), P. mirabilis to imipinem (2%), and Enterobacter to amikacin, ertapenem and tigecycline (3%). Resistance of P. aeruginosa varied between 2% to colistin and 24% to levofloxacin. For the Gram-positive bacteria, 79.1% of E. faecalis were resistant to erythromycin while 70% of CoPS were resistant to cefoxitin, but no isolate was resistant (0%) to linezolid, and only 1% to teicoplanin. Except for Enterobacter spp that showed significant increase in resistance rates (by 250%) to piperacillin/tazobactam in 2019 over 2018, resistance rates of other Gram-negative isolates significantly decreased in 2019 compared to 2018 (p<0.05). For the Gram-positive isolates, resistance rates to many antibiotics tested significantly increased (by a factor of 36.5 - 2569%) in 2019 compared to 2018 among E. faecalis isolates in contrast to the rates for CoPS which significantly decreased by 16.7 - 65.7%, except for penicillin G which increased by a factor of 123%. Conclusion: Overuse and misuse of antibiotics, which is possible because of the easy access of the populace to these drugs, is a leading factor contributing to the high antibiotic resistance rates in this study. There is need to promote awareness of antimicrobial resistance in Lebanon among students especially in non-health related majors and enactment of govermental policy that will limit access to antibiotics. Keywords: antibiotic resistance; changing pattern; hospitalized patients; retrospective   French title: Une etude retrospective des profils de resistance aux antibiotiques de pathogenes bacteriens isoles de patients dans deux hopitaux libanais pendant deux annees consecutives (2018 et 2019) Contexte: La mauvaise utilisation des antibiotiques est le principal facteur favorisant l'emergence de la resistance bacterienne, une situation qui est devenue un serieux defi de sante publique. Parmi les principales bacteries qui ont developpe une resistance aux antibiotiques figurent Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae et Pseudomonas aeruginosa, qui ont provoque des infections chez les patients, entrainant une mortalite considerable. L'objectif de cette etude retrospective est d'evaluer les taux de resistance aux antibiotiques des pathogenes bacteriens isoles a partir d'echantillons cliniques dans deux hopitaux Libanais entre les annees 2018 et 2019. Methodologie: Les isolats bacteriens preleves sur des patients hospitalises dans deux hopitaux, Haroun et Bekaa, au Liban pour 2018 et 2019, ont ete analyses. L'isolement et l'identification des bacteries ont ete realises au laboratoire de chaque hopital en utilisant des methodes microbiologiques conventionnelles. Les tests de sensibilite aux antimicrobiens (AST) de chaque isolat bacterien aux antibiotiques ont ete realises par le test de diffusion sur disque et interpretes selon les directives EUCAST, CLSI ou WHO/AST. Des comparaisons des taux moyens de resistance de chaque isolat a des antibiotiques individuels par annee d'isolement ont ete effectuees a l'aide du test Z et p<0,05 a ete considere comme statistiquement significatif. Resultats: Il y a eu un total de 1698 isolats de bacteries recuperes de patients hospitalises dans les deux hopitaux durant 2018 et 2019, dont 87,5% etaient a Gram negatif et 12,5% etaient des bacteries a Gram positif. Les isolats a Gram negatif les plus frequents etaient E. coli (66,1%), suivis de P. aeruginosa (13,3%), K. pneumoniae (7,7%), Proteus mirabilis (6,7%) et Enterobacter spp (6,3%), tandis que les staphylocoques a coagulase positive CoPS (68,4%) et E. faecalis (31,6%) etaient les deux isolats Gram positifs. Parmi les isolats a Gram negatif sur la periode de deux ans, 72,2% d'E. coli et 76,3% de K. pneumoniae etaient resistants a la ceftazidime, 93% de P. mirabilis a la colistine et 98% d'Enterobacter a la cefoxitine, mais faible les taux de resistance ont ete demontres par E. coli a l'imipenem (1%), K. pneumoniae a la tigecycline et a l'amikacine (0,9%), P. mirabilis a l'imipinem (2%) et Enterobacter a l'amikacine, a l'ertapenem et a la tigecycline (3%). La resistance de P. aeruginosa variait entre 2% a la colistine et 24% a la levofloxacine. Pour les bacteries Gram positif, 79,1% des E. faecalis etaient resistantes a l'erythromycine tandis que 70% des CoPS etaient resistantes au cefoxitin, mais aucun isolat n'etait resistant (0%) au linezolide et seulement 1% a la teicoplanine. A l'exception d'Enterobacter spp qui ont montre une augmentation significative des taux de resistance (de 250%) a la  piperacilline/tazobactam en 2019 par rapport a 2018, les taux de resistance des autres isolats a Gram negatif ont considerablement  diminue en 2019 par rapport a 2018 (p<0,05). Pour les isolats Gram-positifs, les taux de resistance a de nombreux antibiotiques testes ont augmente de maniere significative (d'un facteur de 36,5 a 2569%) en 2019 par rapport a 2018 parmi les isolats d'E. faecalis contrairement aux taux de CoPS qui ont significativement diminue de 16,7 a 65,7%, a l'exception de la penicilline G qui a augmente d'un facteur de 123%. Conclusion: la surutilisation et la mauvaise utilisation des antibiotiques, ce qui est possible en raison de l'acces facile de la population a ces medicaments, est l'un des principaux facteurs contribuant aux taux eleves de resistance aux antibiotiques dans cette etude. Il est necessaire de promouvoir la sensibilisation a la resistance aux antimicrobiens au Liban parmi les etudiants, en particulier dans les specialisations non liees a la sante, et la promulgation d'une politique gouvernementale qui limitera l'acces non controle aux antibiotiques. Mots cles: resistance aux antibiotiques; changement de modele; patients hospitalises; retrospective