Molecular Detection of blaIMP Genes in Metallo-Beta-Lactamase Producing Clinical Gram-Negative Isolates.

BACKGROUND: The use of carbapenem antibiotics in the treatment of serious Gram-negative bacterial infections is under threat due to the emergence of the blaIMP gene amongst the bacterial pathogens. METHODS: The present descriptive cross-sectional study aimed to determine the occurrence of the blaIMP gene and minimum inhibitory concentrations (MICs) of the bacterial pathogens. The carbapenem-resistant isolates were screened out for the detection of MBLs by using the modified Hodge test and disk potentiation method. MBL producing strains were tested for the presence of the blaIMP gene by using PCR technique. The MICs of the blaIMP gene positive bacterial isolates were detected on the Vitek 2 system (bioMerieux). RESULTS: The primary source of MBLs and blaIPM gene carrying bacterial pathogens was blood (38.5%). We isolated 104 bacterial isolates in the initial screening of carbapenem resistance. Metallo-beta-lactamases (MBLs) were detected in 76 (73%) of the isolates which predominantly included 27 (26%) Klebsiella pneumoniae, 20 (19.2%) Acinetobacter baumannii, 16 (15.4%) Pseudomonas aeruginosa, and 11 (10.6%) E. coli while the other Gram-nega-tive MBL producing bacteria were few in number. The blaIPM gene was detected in 1 (1.3%) case of Acinetobacter baumannii and 1 (1.3%) case of Stenotrophomonas maltophilia. These strains were found to be multi-drug resistant with high MICs (≥ 8 to ≥ 256 µg/mL) against the majority of the drugs. CONCLUSIONS: The emergence of the blaIPM gene is a matter of serious concern as it left us with limited treatment options of minocycline, tigecycline, and levofloxacin. The horizontal transfer of blaIPM gene in other Gram-negative isolates can lead the epidemics of multidrug resistance.

Molecular insights of Carbapenem resistance Klebsiella pneumoniae isolates with focus on multidrug resistance from clinical samples.

BACKGROUND: Carbapenem are the last-line antibiotic, defence against Gram-negative extended spectrum ß-lactamases producers (ESBLs). Carbapenem resistance Enterobacteriaceae especially Carbapenem resistant-Klebsiella pneumoniae (CR-KP) is recognized as one of the well-known public health problem, which is increasingly being reported around the world. The present study was focused to analyse the prevalence and characterization of antibiotic resistance K. pneumoniae in centre region of Tamil Nadu, India. METHODOLOGY: Totally 145 suspected K. pneumoniae isolates [Urine, Pus, Sputum, Blood and Biopsy] obtained from hospitals of Central South India. The isolates were subjected to biochemical and molecular identification technique, following with antibiotic resistance pattern by standard antibiotic sensitivity test. Multidrug resistance (MDR) with ß-lactamase producing Carbapenem resistant K. pneumoniae (CR-KP) strains were screened by classical sensitivity method and also drug resistance encoded gene. Also, molecular typing of the MDR strains were characterized by Pulsed-Field Gel Electrophoresis (PFGE). Further, the outer membrane protein (OmpK35 and 36) related Carbapenem resistance were characterized. RESULTS: Totally, 61% of isolates were confirmed as K. pneumoniae, 75 % of isolates were MDR including 58% carbapenem and 97% ESBL antibiotics and grouped into 17 distinct resistant patterns. The MDR KP isolates shows positive for blaCTXM-1 (92 %) gene followed by blaSHV (43 %), blaTEM (36 %), blaNDM-1 (26 %), blaGES (20 %) and blaIMP-1 (8 %). Moreover, 62 % CR-KP isolates loses OmpK36 and 33% isolates loses OmpK35. CONCLUSIONS: Loss of OmpK36 were highly an influence the cefoxitin and carbapenem resistance. Sixteen different PFGE patterns have been observed among the 18 MDR isolates. Eventually, ESBL as well as CR-KP were diverse in genetic makeup and often associated with hyper virulence hvKP should be of serious concern.

Anti-biofilm activity of plant derived extracts against infectious pathogen-Pseudomonas aeruginosa PAO1.

BACKGROUND: Biofilm forming ability of Pseudomonas aeruginosa make them vulnerable, because it makes them recalcitrant against various antibiotics. Quorum sensing (QS) is cell density based signaling that helps in bacterial cell-cell communication, which regulated various virulence factors such as pigment and biofilm formation that contribute in the establishment of chronic infections. The interruption of QS is one of the effective approach to control various virulence factors. Present study was intended with the aim to authenticate antibiofilm potential in different solvents based extracts of selected medicinal plant species viz. Berginia ciliata, Clematis grata and Clematis viticella traditionally used by the inhabitants of Himalayan region of Pakistan to treat various pathogenic diseases. P. aeruginosa PAO1, an opportunistic pathogen and involves in various life-threatening infections specifically in immune deficient patients was used as a model pathogen. METHODS: Plants were extracted in various organic (ethanol, methanol, acetone, ethyl acetate, hexane, chloroform) as well as in aqueous solvents and their ability to inhibit biofilm was measured. Biofilm of PAO1 was grown in Jensen's medium while growing at 30°C and crystal violet assay was performed to assess the biofilm inhibiting activity of plant extracts. RESULTS: Solvents play a vital role in extraction of plant components and it was found that the plants in various solvents exhibit different activity against the PAO1 biofilm. Comparatively, 1% methanolic extract of B. ciliata (rhizome with skin), showed more than 80% inhibition of biofilm formation without effecting on the growth of the bacterium. Significant correlation between flavonoids content and antibiofilm activity in methanolic extract revealed the contribution of secondary metabolites in P. aeruginosa (PAO1) biofilm inhibition. CONCLUSION: Our study revealed that plants under investigation more specifically B. ciliata could be a potential candidate for drug discovery to treat P. aeruginosa PAO1, induced infectious diseases especially for its biofilm treatment.