scholarly journals Correlation of the expression of acrB and the regulatory genes marA, soxS and ramA with antimicrobial resistance in clinical isolates of Klebsiella pneumoniae endemic to New York City

2009 ◽  
Vol 64 (2) ◽  
pp. 278-283 ◽  
Author(s):  
S. Bratu ◽  
D. Landman ◽  
A. George ◽  
J. Salvani ◽  
J. Quale
2018 ◽  
Vol 24 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Nyla Manning ◽  
Gregory Balabanian ◽  
Michael Rose ◽  
David Landman ◽  
John Quale

2006 ◽  
Vol 50 (10) ◽  
pp. 3396-3406 ◽  
Author(s):  
Frank M. Kaczmarek ◽  
Fadia Dib-Hajj ◽  
Wenchi Shang ◽  
Thomas D. Gootz

ABSTRACT Clinical isolates of Klebsiella pneumoniae resistant to carbapenems and essentially all other antibiotics (multidrug resistant) are being isolated from some hospitals in New York City with increasing frequency. A highly related pair of K. pneumoniae strains isolated on the same day from one patient in a hospital in New York City were studied for antibiotic resistance. One (KP-2) was resistant to imipenem, meropenem, and sulopenem (MICs of 16 to 32 μg/ml) while the other (KP-1) was susceptible (MIC of 0.5 μg/ml); both contained the bla ACT-1, bla SHV-1, and bla TEM-1 β-lactamases. bla ACT-1 in both strains was encoded on a large ∼150-kb plasmid. Both isolates contained an identical class 1 integron encoding resistance to aminoglycosides and chloramphenicol. They each had identical insertions in ompK35 and ompK36, resulting in disruption of these key porin genes. The carbapenem-resistant and -susceptible isolates were extensively studied for differences in the structural and regulatory genes for the operons acrRAB, marORAB, romA-ramA, soxRS, micF, micC, phoE, phoBR, rpoS, and hfq. No changes were detected between the isolates except for a significant down-regulation of ompK37, phoB, and phoE in KP-2 as deduced from reverse transcription-PCR analysis of mRNA and polyacrylamide gel electrophoresis separation of outer membrane proteins. Backcross analysis was conducted using the wild-type phoE gene cloned into the vector pGEM under regulation of its native promoter as well as the lacZ promoter following transformation into the resistant KP-2 isolate. The wild-type gene reversed carbapenem resistance only when under control of the heterologous lacZ promoter. In the background of ompK35-ompK36 gene disruption, the up-regulation of phoE in KP-1 apparently compensated for porin loss and conferred carbapenem susceptibility. Down-regulation of phoE in KP-2 may represent the normal state of this gene, or it may have been selected from KP-1 in vivo under antibiotic pressure, generating the carbapenem-resistant clone. This is the first study in the Enterobacteriaceae where expression of the phosphate-regulated PhoE porin has been associated with resistance to antimicrobials. Our results with this pair of Klebsiella clinical isolates highlight the complex and evolving nature of multiple drug resistance in this species.


2008 ◽  
Vol 52 (9) ◽  
pp. 2999-3005 ◽  
Author(s):  
Simona Bratu ◽  
David Landman ◽  
Don Antonio Martin ◽  
Claudiu Georgescu ◽  
John Quale

ABSTRACT Acinetobacter baumannii strains resistant to all β-lactams, aminoglycosides, and fluoroquinolones have emerged in many medical centers. Potential mechanisms contributing to antimicrobial resistance were investigated in 40 clinical isolates endemic to New York City. The isolates were examined for the presence of various β-lactamases, aminoglycoside-modifying enzymes, and mutations in gyrA and parC. Expression of the genes encoding the β-lactamase AmpC, the efflux systems AdeABC and AbeM, and the OmpA-like porin was also examined by real-time reverse transcription-PCR. No VIM, IMP, KPC, OXA-23-type, OXA-24-type, or OXA-58 β-lactamases were detected, although several isolates had acquired bla SHV-5. Most cephalosporin-resistant isolates had increased levels of expression of ampC and/or had acquired bla SHV-5; however, isolates without these features still had reduced susceptibility to cefepime that was mediated by the AdeABC efflux system. Although most isolates with ISAba1 upstream of the bla OXA-51-like carbapenemase gene were resistant to meropenem, several remained susceptible to imipenem. The presence of aminoglycoside-modifying enzymes and gyrase mutations accounted for aminoglycoside and fluoroquinolone resistance, respectively. The increased expression of adeABC was not an important contributor to aminoglycoside or fluoroquinolone resistance but did correlate with reduced susceptibility to tigecycline. The expression of abeM and ompA and phenotypic changes in OmpA did not correlate with antimicrobial resistance. A. baumannii has become a well-equipped nosocomial pathogen; defining the relative contribution of these and other mechanisms of antimicrobial resistance will require further investigation.


2010 ◽  
Vol 16 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Melissa R. Wong ◽  
Vasudha Reddy ◽  
Heather Hanson ◽  
Kristen M. Johnson ◽  
Benjamin Tsoi ◽  
...  

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. e00624-18 ◽  
Author(s):  
Simon H. Williams ◽  
Xiaoyu Che ◽  
Ashley Paulick ◽  
Cheng Guo ◽  
Bohyun Lee ◽  
...  

ABSTRACTHouse mice (Mus musculus) thrive in large urban centers worldwide. Nonetheless, little is known about the role that they may play in contributing to environmental contamination with potentially pathogenic bacteria. Here, we describe the fecal microbiome of house mice with emphasis on detection of pathogenic bacteria and antimicrobial resistance genes by molecular methods. Four hundred sixteen mice were collected from predominantly residential buildings in seven sites across New York City over a period of 13 months. 16S rRNA sequencing identifiedBacteroidetesas dominant and revealed high levels ofProteobacteria. A targeted PCR screen of 11 bacteria, as indicated by 16S rRNA analyses, found that mice are carriers of several gastrointestinal disease-causing agents, includingShigella,Salmonella,Clostridium difficile, and diarrheagenicEscherichia coli. Furthermore, genes mediating antimicrobial resistance to fluoroquinolones (qnrB) and β-lactam drugs (blaSHVandblaACT/MIR) were widely distributed. Culture and molecular strain typing ofC. difficilerevealed that mice harbor ribotypes associated with human disease, and screening of kidney samples demonstrated genetic evidence of pathogenicLeptospiraspecies. In concert, these findings support the need for further research into the role of house mice as potential reservoirs for human pathogens and antimicrobial resistance in the built environment.IMPORTANCEMice are commensal pests often found in close proximity to humans, especially in urban centers. We surveyed mice from seven sites across New York City and found multiple pathogenic bacteria associated with febrile and gastrointestinal disease as well as an array of antimicrobial resistance genes.


2016 ◽  
Vol 3 (suppl_1) ◽  
Author(s):  
Sharon Vuppula ◽  
Sharon Vuppula ◽  
Carla Lee ◽  
Carla Lee ◽  
Henry Pollack

2013 ◽  
Vol 57 (3) ◽  
pp. 1542-1545 ◽  
Author(s):  
Liang Chen ◽  
Kalyan D. Chavda ◽  
Roberto G. Melano ◽  
Michael R. Jacobs ◽  
Michael H. Levi ◽  
...  

ABSTRACTWe report the nucleotide sequence of a novelblaKPC-2-harboring IncFIIK1plasmid, pBK32179, isolated from a carbapenem-resistantKlebsiella pneumoniaeST258 strain from a New York City patient. pBK32179 is 165 kb long, consists of a large backbone of pKPN3-like plasmid, and carries an 18.5-kbblaKPC-2-containing element that is highly similar to plasmid pKpQIL. pBK32179-like plasmids were identified in 8.3% of strains in a collection of 96K. pneumoniaeisolates from hospitals in the New York City area.


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