Abstract
Background: Multidrug resistance among different pathogens is increasing immensely day by day. To control these problems, we need
new potent antimicrobial agents in repository of antibiotics.
Objectives: This study aimed at investigation of antibiotics resistance pattern of pathogenic Klebsiella strains isolated from clinical
samples in Lahore region Pakistan and study inhibition of resistant strains by natural extracts obtained from actinomycetes isolated from
different ecological niches in Pakistan.
Materials and Methods: The isolated Klebsiella strains were identified by morphological, biochemical and physiological characterization
along with 16S rRNA gene sequencing. Antibiotics susceptibility was determined by standard Kirby Bauer disc diffusion assay. The biological
and chemical screening was performed for detection of active secondary metabolites produced by actinomycetes against resistant
Klebsiella strains. Biological screenings include antimicrobial activity by agar diffusion assay and brine shrimp microwell cytotoxicity
assay. In chemical screening, the crude extracts of actinomycetes strains were analysed by TLC and HPLC-UV techniques.
Results: The isolated Klebsiella strains showed resistance against most of the antibiotics as follows; ceftriaxone > cephalexin > cefpirome
> cefoxitin = cefepime > levofloxacin > ciprofloxacin = ceftrazidime = fusidum > cefoperazone > ampicillin sulbactam. The actinomycetes
strain A19, A20, A2, A10, A6 and A8 exhibited remarkable activity against resistant Klebsiella strains. The strains A19 and 20 showed excellent
inhibitory effects on all isolated multidrug resistant Klebsiella strains.
Conclusions: The clinical Klebsiella strains isolated from Lahore region, Pakistan exhibited resistance to most commonly used antibiotics,
which can be a serious threat to public health. The study reported some potential actinomycetes strains, which exhibit promising activity
against multidrug resistant Klebsiella strains.