Biofilm development and resistance to antibiotics in Klebsiella pneumoniae isolated from clinical specimens in Samawwa city, Iraq

Abstract

Biofilm formation is a critical factor for K. pneumoniae's ability to cause disease, as it shields the
bacteria from the immune response of serum and phagocytosis. K. pneumoniae commonly employs biofilm
formation as a survival strategy. A global issue of bacteria developing resistance to multiple drugs causes
numerous deaths each year. To address the rising prevalence of drug-resistant bacteria, various legislative
actions have been implemented to restrict or eliminate the use of antibiotics. Klebsiella pneumoniae, a
bacteria commonly associated with healthcare-related infections, exhibits high levels of antibiotic resistance
and is known for its ability to form biofilms. This research aimed to isolate and identify K. pneumoniae
strains obtained from clinical samples in Samawwa city , Iraq, and also determining their antibiotic
resistance patterns and capacity for biofilm production. The isolation of K. pneumoniae was carried out on
inpatients in Samawwa between September and December 2022. The identification process involved
analyzing colony morphology on selective media (Hichrom agar and ESBL agar), microscopic examination,
and biochemical testing. Antibiotic susceptibility testing and biofilm-producing capacity assessment were
conducted using the Kirby-Bauer disk diffusion method and microtiter plate assays which is known as a 96-
well plate, is a quantitative method used with a microplate reader to determine the production of biofilm,
respectively .A total of 85(40%) K. pneumoniae isolates were isolated from 215 total clinical samples during
the study. The majority of the samples were gathered from male and female patients spanning an age range
of 3 to 90 years. These samples were primarily acquired from urine specimens.(67%). The majority of K.
pneumoniae strains exhibited high levels of antibiotic resistance, except for meropenem, imipenem, and
norfloxacin, which showed better inhibition .18%; 7% and 7.5% of resistance, respectively. In addition, 24
isolates were tested for capacity to biofilm production, 17 (63%) isolates were biofilm producers, with 10
(41%) isolates as moderate, and 6 (38%) isolates as weak biofilm producers.