Identification of strain harboring both aac(6')-Ib and aac(6')-Ib-cr variant simultaneously in Escherichia coli and Klebsiella pneumoniae

Kim, Yun Tae; Jang, Ji Hyun; Kim, Hyun-Chul; Kim, Hyog Yeong; Lee, Kyoung Ryul; Park, Kyung Sun; Lee, Hee Joo; Kim, Young Jin

doi:10.5483/bmbrep.2011.44.4.262

Cited by 13 publications

(10 citation statements)

References 18 publications

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“…The gene aac (6′)-Ib-cr, a variant gene of the aminoglycoside acetyltransferase, was also present in most of strains that presented fluoroquinolone and/or aminoglycoside resistance. This finding is consistent with others studies that have shown that aac (6′)-Ib-cr may be associated with antibacterial resistance against fluoroquinolone and aminoglycoside ( Kim et al, 2009 , 2011 ) antibiotics.…”

Section: Discussionsupporting

confidence: 93%

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

et al. 2020

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Serratia marcescens has emerged as an important opportunistic pathogen responsible for nosocomial and severe infections. Here, we determined phenotypic and molecular characteristics of 54 S. marcescens isolates obtained from patient samples from intensive-care-unit (ICU) and neonatal intensive-care-unit (NIUC) of a Brazilian tertiary hospital. All isolates were resistant to beta-lactam group antibiotics, and 92.6% (50/54) were not susceptible to tigecycline. Furthermore, 96.3% showed intrinsic resistance to polymyxin E (colistin), a last-resort antibiotic for the treatment of infections caused by MDR (multidrug-resistant) Gram-negative bacteria. In contrast, high susceptibility to other antibiotics such as fluoroquinolones (81.5%), and to aminoglycosides (as gentamicin 81.5%, and amikacin 85.2%) was found. Of all isolates, 24.1% were classified as MDR. The presence of resistance and virulence genes were examined by PCR and sequencing. All isolates carried KPC-carbapenemase (bla KPC) and extended spectrum beta-lactamase bla TEM genes, 14.8% carried bla OXA−1 , and 16.7% carried bla CTX−M−1group genes, suggesting that bacterial resistance to β-lactam antibiotics found may be associated with these genes. The genes SdeB/HasF and SdeY/HasF that are associated with efflux pump mediated drug extrusion to fluoroquinolones and tigecycline, respectively, were found in 88.9%. The aac(6)-Ib-cr variant gene that can simultaneously induce resistance to aminoglycoside and fluoroquinolone was present in 24.1% of the isolates. Notably, the virulence genes to (i) pore-forming toxin (ShlA); (ii) phospholipase with hemolytic and cytolytic activities (PhlA); (iii) flagellar transcriptional regulator (FlhD); and (iv) positive regulator of prodigiosin and serratamolide production (PigP) were present in 98.2%. The genetic relationship among the isolates determined by ERIC-PCR demonstrated that the vast majority of isolates were grouped in a single cluster with 86.4% genetic similarity. In addition, many isolates showed 100% genetic similarity to each other, suggesting that the S. marcescens that circulate in this ICU are closely related. Our results suggest that the antimicrobial resistance to many drugs

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Section: Discussionsupporting

confidence: 93%

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

et al. 2020

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“…In the study by Kim et al, performed in South Korea, 55.3% of the isolates (n = 85) were carrying the aac(6')-Ib-cr gene, which is consistent with the findings of the present study (35). In other studies performed by Goudarzi in Iran (city of Tehran) and Yang in Korea, the prevalence of aac(6')-Ib-cr gene is reported as 68.8% and 77.5%, respectively, which is higher than the prevalence reported in the present study (13,31).…”

Section: Discussionsupporting

confidence: 92%

Frequency of qnr and aac(6’)Ib-cr Genes Among ESBL-Producing Klebsiella pneumoniae Strains Isolated from Burn Patients in Kermanshah, Iran

Vaziri

Afsharian

Mansouri

et al. 2020

Jundishapur J Microbiol

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Background: Assessment of bacteria such as Klebsiella pneumonia has shown that Plasmid-mediated quinolone resistance (PMQR) affects antibiotics resistance (e.g., quinolones). Objectives: We studied the prevalence of qnr and aac(6’)Ib-cr genes in extended-spectrum beta-lactamase (ESBL)-producing K. pneumonia strains isolated from burn wounds of patients in the city of Kermanshah, Iran. Methods: This descriptive-analytical study was conducted on 126 K. pneumonia strains isolated collected from burn wounds. Biochemical tests were used to detect the strains. The frequency of the ESBL-producing isolates was determined by phenotypic tests of the combination disk (CD) method after determining the antibiotic susceptibility pattern of the isolates through the Kirby-Bauer disc diffusion test. The prevalence of the qnr and aac(6’)-Ib-cr genes was determined using their special primers as well as polymerase chain reaction (PCR). Results: Of the 126 K. pneumonia isolates, 52 (41.3%) were identified as ESBL-producing strains. ESBL-producing isolates showed higher resistance against antibiotics than non-ESBL-producing ones. PMQR relevance and resistance to ciprofloxacin were, respectively, determined at 80.76% and 59.6%. The most frequent gene was aac(6’)-Ib-cr (n = 70, 55.6%), followed by the qnrB (n = 44, 34.9%. Conclusions: This study showed a high prevalence of qnr genes in ESBL-producing K. pneumonia isolates and antibiotic resistance. Given the horizontal transmission of antibiotic resistance genes among bacteria by mobile genetic elements, timely identification of infections caused by ESBL-producing and antimicrobial-resistant K. pneumonia strains is of paramount importance.

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“…Since the first detection of the AAC(6′)-Ib-cr variant there have been numerous reports of its presence, and variants of it, across the world in different genetic environments suggesting an extraordinary ability to disseminate (Quiroga et al, 2007; Cattoir and Nordmann, 2009; Strahilevitz et al, 2009; Rodriguez-Martinez et al, 2011; Ruiz et al, 2012; De Toro et al, 2013). Furthermore, there have been cases where a strain was found to simultaneously include genes coding for AAC(6′)-Ib and AAC(6′)-Ib-cr (Kim et al, 2011). AAC(6′)-Ib is also found fused to the C-terminal end of AAC(3)-Ib protein within a class I integron found in a Pseudomonas aeruginosa strain (Dubois et al, 2002) and to the C-terminus of the AAC(6′)-30 also within a P. aeruginosa class I integron (Mendes et al, 2004).…”

Section: The Aac(6′)-ib Proteinmentioning

confidence: 99%

Rise and dissemination of aminoglycoside resistance: the aac(6′)-Ib paradigm

2013

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Enzymatic modification is a prevalent mechanism by which bacteria defeat the action of antibiotics. Aminoglycosides are often inactivated by aminoglycoside modifying enzymes encoded by genes present in the chromosome, plasmids, and other genetic elements. The AAC(6′)-Ib (aminoglycoside 6′-N-acetyltransferase type Ib) is an enzyme of clinical importance found in a wide variety of gram-negative pathogens. The AAC(6′)-Ib enzyme is of interest not only because of his ubiquity but also because of other characteristics, it presents significant microheterogeneity at the N-termini and the aac(6′)-Ib gene is often present in integrons, transposons, plasmids, genomic islands, and other genetic structures. Excluding the highly heterogeneous N-termini, there are 45 non-identical AAC(6′)-Ib related entries in the NCBI database, 32 of which have identical name in spite of not having identical amino acid sequence. While some variants conserved similar properties, others show dramatic differences in specificity, including the case of AAC(6′)-Ib-cr that mediates acetylation of ciprofloxacin representing a rare case where a resistance enzyme acquires the ability to utilize an antibiotic of a different class as substrate. Efforts to utilize antisense technologies to turn off expression of the gene or to identify enzymatic inhibitors to induce phenotypic conversion to susceptibility are under way.

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Identification of strain harboring both aac(6')-Ib and aac(6')-Ib-cr variant simultaneously in Escherichia coli and Klebsiella pneumoniae

Cited by 13 publications

References 18 publications

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

Frequency of qnr and aac(6’)Ib-cr Genes Among ESBL-Producing Klebsiella pneumoniae Strains Isolated from Burn Patients in Kermanshah, Iran

Rise and dissemination of aminoglycoside resistance: the aac(6′)-Ib paradigm

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