Study of biofilm formation and antibiotic resistance pattern of gram-negative Bacilli among the clinical isolates at BPKIHS, Dharan

Abstract

ObjectivesGram-negative bacilli are the common causative agents for community-acquired, nosocomial and opportunistic infections. The recent upsurge of biofilm, as well as beta-lactamases producing strains, have synergistically led to the extensive dissemination of multi-drug resistant gram-negative bacilli. This study was carried out with an intention to detect the biofilm formation by gram-negative bacilli and determine their antibiogram along with the detection of extended-spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) production.ResultsAmong 314 isolates, Escherichia coli (38%) were the predominant isolates followed by Acinetobacter spp. (20%), Klebsiella spp. (16%), and Pseudomonas spp. (12%). Overall, 197 (62.73%) of isolates were biofilm positive. 84 (26.75%) and 51 (16.24%) were confirmed as ESBL and MBL producers respectively. The association between MBL production and biofilm formation was statistically significant (χ2 = 10.20, P value= 0.002) whereas it was insignificant between ESBL and biofilm production (χ2 = 0.006, P-value= 0.937). Most of the biofilm and MBL producing strains were multi-drug resistant.

Association of biofilm production in ESBL and MBL producing clinical isolates of Pseudomonas aeruginosa

“…In the present study, it was found that there is an association between ESBL production and biofilm formation (Statistically significant, p= 0.002). It was similar to another study [26] but the contrast study done by Dumaru et al [12]. No statistically significant association could be established between MBL production and biofilm production (Statistically insignificant, p=0.19) which was in agreement with another study [20].…”

“…In the present study, among a total of 82 isolates of P. aeruginosa, 22(26.3%) were biofilm-producer and this finding is comparable with other studies which show (27.05%) [20], (32.3%) [21] and (33%) [22], but in contrast with others who showed higher rate of biofilm production (73.68%) [12] and (83.33%) [23]. This variation in the rate of isolation also may be due to sample size, type of specimen studied because medical devices were frequently colonized by biofilm-forming organisms and the various methods used for biofilm identification like Congo red agar method or Tissue culture plate which were showing a higher rate of detection.…”

“…The difference was statistically significant (p < 0.05). It is similar to findings from other studies for most of the antibiotics tested [12,21,22]. So Meropenem, colistin, and polymyxin-B remain the treatment of choice for biofilm-producing isolates.…”

“…Studies show that infection by drug-resistant P. aeruginosa leads to increased length of hospital stay, morbidity, and mortality, and chronic infection [18]. The biofilm formation along with beta-lactamase production further complicates the scenario [12]. Production of an extracellular matrix is the hallmarks of a mature biofilm that acts as a barrier for any antibiotics and increases resistance to these antibiotics [19].…”

“…In the present day, antibiotic resistance is an emerging problem and especially higher antibiotics like carbapenem are under the threat due to the widespread presence of carbapenemase (mainly Metallo Beta-lactamase). The biofilm formation and beta-lactamases (like ESBL and MBL) production synergistically contribute to the wide distribution of multidrug resistant strains [12]. So the present study was conducted to identify, biofilmproducing isolates of P. aeruginosa along with their antibiotic resistance pattern and ESBL and MBL production.…”