Study On The Resistance And The Plamid-mediated Quinolone Resistance Mechanism Among Clinical Isolates Of Klebsiella Pneumoniae

BackgroundKlebsiella pneumoniae is the common pathogen of nosocomial infection, the detectionrate was the three of the Grand negative bacteria. It can infect the nonparasitic part ofthe human body, inducing the infection, such as peritonitis, cholecystitis, cystitis anddiarrhea. If not selected the antibiotics timely and reasonable can leading to the patientdead, when infecting with resistant strains. Thus, in order to better guide clinical therapy,monitor the resistance of Klebsiella pneumonia closely was necessary.ObjectiveIn order to guide clinical therapy, we investigated the antimicrobial agents resistance ofclinical Klebsiella pneumoniae Isolates and study the sensitivity of Klebsiellapneumoniae clinical isolats from the First Affiliated Hospital of Anhui MedicalUniversity against13antimicrobial agents. Found out the Distribution among ESBLsand non-ESBLs producer Klebsiella pneumoniae.Methods50clinical isolates of Klebsiella pneumoniae were collected from the First AffiliatedHospital of Anhui Medical University, in Anhui province, China. According to thestandard procedure described by the Clinical and Laboratory Standards Institute CLSI 2010(S20), the susceptibility test to50clinical Klebsiella pneumoniae isolates against13antimicrobial agents was performed by means of Agar Dilution Method.ESBLs-producing isolates were confirmed by phenotypic confirmatory test (the diskdiffusion method).ResultsAccording to the antimicrobial susceptibility results，ESBLs were detected in64.0%(32/50) of K. pneumoniae in this study. The resistance rates of K. pneumoniae forPiperacillin (88%), Cefepime (60%), Cefuroxime (84%), Ceftazidime (74%),Cefuroxime (90%), Cefazolin(94%), Aztreonam(72%), Ciprofloxacin (64%),Levofloxacin (70%), Gatifloxacin (64%), Gentamicin (76%), Amikacin (32%),Chloramphenicol (64%).ConclusionsThe resistance rates of clinical Klebsiella pneumoniae isolates were high against13antimicrobial agents. The Resistant strains were more common among ESBLsproducing strains than non-ESBLs. More attention should be paid to survey and detectthe resistant strains, prevent the prevalence of those strains. BackgroundKlebsiella pneumoniae belongs to the Gram-negative bacilli, often colonize atrespiratory and intestinal. It course respiratory tract infections, urinary tract infectionand abdominal infection. In recent years, quinolones are broadly used in clinicalinfection coursed by Klebsiella pneumoniae. Therefore, with the wider use in clinicalapplication, quinolone resistance has also been widespread concerned.The mechanismof quinolones resistance was considered to be mediated by the chromosome in the1990s, such as targets change, the efflux pump. Since the first plasmid-mediatedquinolone resistance (PMQR) determinants qnr was reported in1998, other majorgroups of determinants have been identified. These PMQR genes can convey in thesame and even different species of bacteria by horizontal transmission. Consequently,the sensitive bacteria become resistant.ObjectiveWe investigated the prevalence of PMQR determinants among K. pneumoniae isolatesfrom the First Affiliated Hospital of Anhui Medical University, in Anhui province,China.MethodsAll the isolates were screened for the genes PMQR by PCR. Positive PCR productswere confirmed by direct sequencing. Sequences were compared with sequencesdeposited in GenBank. ResultsResults showed that qnrB4, qnrS1, aac(6’)-Ib-cr was identified in6.0%(3/50),12%(6/50),16%(8/50) of the K. pneumoniae isolates, respectively. Among thesePMQR-positive isolates, qnrS1and qnrA being detected in combination in4%(2/50)isolates. In19PMQR positive strains,18stains were resistance to ciprofloxacin. TheERIC-PCR revealed that most of these strains were not clonal related. Clone spread wasfound in some islotes.ConclusionsPMQR was identified in38%(19/50) of the50K. pneumoniae isolates. In19PMQRpositive strains,94.7%(18/19) of the strains were resistance to ciprofloxacin. It showedthat PMQR gene and ciprofloxacin resistance is closely related. In PMQR positivestrains,13ESBLs positive strains were resistance to ciprofloxacin. Multidrug resistantmay exist. Otherwise, in19positive strains, most of them were not clonal related. Clonespread was found in some islotes.