scholarly journals Genetic characterization of Shigella spp. isolated from diarrhoeal and asymptomatic children

2014 ◽  
Vol 63 (7) ◽  
pp. 903-910 ◽  
Author(s):  
Santanu Ghosh ◽  
Gururaja P. Pazhani ◽  
Swapan Kumar Niyogi ◽  
James P. Nataro ◽  
Thandavarayan Ramamurthy
Keyword(s):  
Virulence Genes ◽  
Multidrug Resistant ◽  
Class 1 Integron ◽  
Genetic Characteristics ◽  
Asymptomatic Children ◽  
Class 1 ◽  
Shigella Spp ◽  
Encoding Gene ◽  
Encoding Genes

Phenotypic and genetic characteristics of Shigella spp. isolated from diarrhoeal and asymptomatic children aged up to 5 years were analysed in this study. In total, 91 and 17 isolates were identified from diarrhoeal (case) and asymptomatic (control) children, respectively. All the isolates were tested for antimicrobial resistance, the presence of integrons, plasmid-mediated quinolone resistance (PMQR), virulence-associated genes and Shigella pathogenicity island (SH-PAI). The majority of the Shigella spp. from cases (68.1 %) and controls (82.3 %) were found to be resistant to fluoroquinolones. Integron carriage was detected more in cases (76.9 %) than in controls (35.5 %). Atypical class 1 integron was detected exclusively in Shigella flexneri from cases but not from the controls. PMQR genes such as aac(6′)-Ib-cr and qnrS1 were detected in 82.4  and 14.3 % of the isolates from cases and in 53 and 17.6 % in controls, respectively. Shigella isolates from cases as well as from controls were positive for the invasive plasmid antigen H-encoding gene ipaH. The other virulence genes such as virF, sat, setA, setB, sen and ial were detected in Shigella isolates in 80.2, 49.4, 27.4, 27.4, 80.2 and 79.1 % of cases and in 64.7, 52.9, 17.6, 17.6, 64.7 and 64.7 % of controls, respectively. The entire SH-PAI was detected in S. flexneri serotype 2a from cases and controls. In an isolate from a control child, the SH-PAI was truncated. Integrons, PMQR and virulence-encoding genes were detected more frequently in cases than in controls. In diarrhoea endemic areas, asymptomatic carriers may play a crucial role in the transmission of multidrug-resistant Shigella spp. with all the putative virulence genes.

scholarly journals Characterization of the New Metallo-β-Lactamase VIM-13 and Its Integron-Borne Gene from a Pseudomonas aeruginosa Clinical Isolate in Spain

2008 ◽  
Vol 52 (10) ◽  
pp. 3589-3596 ◽  
Author(s):  
Carlos Juan ◽  
Alejandro Beceiro ◽  
Olivia Gutiérrez ◽  
Sebastián Albertí ◽  
Margalida Garau ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pcr Amplification ◽  
Class 1 Integron ◽  
Negative Results ◽  
New Variant ◽  
Class B ◽  
Class 1 ◽  
Encoding Gene ◽  
Good Agreement

ABSTRACT During a survey conducted to evaluate the incidence of class B carbapenemase (metallo-β-lactamase [MBL])-producing Pseudomonas aeruginosa strains from hospitals in Majorca, Spain, five clinical isolates showed a positive Etest MBL screening test result. In one of them, strain PA-SL2, the presence of a new bla VIM derivative (bla VIM-13) was detected by PCR amplification with bla VIM-1-specific primers followed by sequencing. The bla VIM-13-producing isolate showed resistance to all β-lactams (except aztreonam), gentamicin, tobramycin, and ciprofloxacin. VIM-13 exhibited 93% and 88% amino acid sequence identities with VIM-1 and VIM-2, respectively. bla VIM-13 was cloned in parallel with bla VIM-1, and the resistance profile conferred was analyzed both in Escherichia coli and in P. aeruginosa backgrounds. Compared to VIM-1, VIM-13 conferred slightly higher levels of resistance to piperacillin and lower levels of resistance to ceftazidime and cefepime. VIM-13 and VIM-1 were purified in parallel as well, and their kinetic parameters were compared. The k cat/K m ratios for the antibiotics mentioned above were in good agreement with the MIC data. Furthermore, EDTA inhibited the activity of VIM-13 approximately 25 times less than it inhibited the activity of VIM-1. VIM-13 was harbored in a class 1 integron, along with a new variant (Ala108Thr) of the aminoglycoside-modifying enzyme encoding gene aacA4, which confers resistance to gentamicin and tobramycin. Finally, the VIM-13 integron was apparently located in the chromosome, since transformation and conjugation experiments consistently yielded negative results and the bla VIM-13 probe hybridized only with the genomic DNA.

scholarly journals Identification and Characterization of Class 1 Integron Resistance Gene Cassettes among Salmonella Strains Isolated from Imported Seafood

2008 ◽  
Vol 75 (4) ◽  
pp. 1192-1196 ◽  
Author(s):  
Ashraf A. Khan ◽  
Elizabeth Ponce ◽  
M. S. Nawaz ◽  
Chorng-Ming Cheng ◽  
Junaid A. Khan ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Southern Hybridization ◽  
Multidrug Resistant ◽  
The Philippines ◽  
Streptomycin Resistance ◽  
Class 1 Integron ◽  
Class 1 ◽  
Identification And Characterization ◽  
Multiple Antibiotics

ABSTRACT A total of 210 Salmonella isolates, representing 64 different serovars, were isolated from imported seafood samples, and 55/210 isolates were found to be resistant to at least one antibiotic. Class 1 integrons from three multidrug-resistant Salmonella enterica strains (Salmonella enterica serovars Newport [strain 62], Typhimurium var. Copenhagen [strain 629], and Lansing [strain 803], originating from Hong Kong, the Philippines, and Taiwan, respectively) were characterized. Southern hybridization of plasmids isolated from these strains, using a class 1 integron probe, showed that trimethoprim-sulfamethoxazole and streptomycin resistance genes were located on a megaplasmid in strain 629. Our study indicates that imported seafood could be a reservoir for Salmonella isolates resistant to multiple antibiotics.

scholarly journals Characterization of multidrug-resistant and extended-spectrum β-lactamase-producing Klebsiella pneumoniae strains from Malaysian hospitals

2009 ◽  
Vol 58 (11) ◽  
pp. 1463-1469 ◽  
Author(s):  
King Ting Lim ◽  
Chew Chieng Yeo ◽  
Rohani Md Yasin ◽  
Ganeswrie Balan ◽  
Kwai Lin Thong
Keyword(s):  
Klebsiella Pneumoniae ◽  
Dna Fingerprinting ◽  
Antibiotic Resistance Gene ◽  
Multidrug Resistant ◽  
Pcr Detection ◽  
Management Problem ◽  
Class 1 Integron ◽  
Extended Spectrum ◽  
Class 1 ◽  
Encoding Genes

The emergence of multidrug-resistant (MDR) and extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae poses a serious antibiotic management problem as resistance genes are easily transferred from one organism to another. Fifty-one strains of K. pneumoniae isolated from sporadic cases in various hospitals throughout Malaysia were analysed by antimicrobial susceptibility testing, PCR detection of ESBL-encoding genes and DNA fingerprinting. Although 27 of the 51 K. pneumoniae strains were MDR (i.e. resistant to three or more classes of antibiotics), the majority of the strains (98 %) were sensitive to imipenem. PCR detection using ESBL gene-specific primers showed that 46 of the K. pneumoniae strains harboured bla SHV, 19 harboured bla CTX-M, 5 harboured bla OXA-1 and 4 harboured bla TEM-1. Class 1 integron-encoded intI1 integrase was detected in 21 of the 51 K. pneumoniae strains and amplification of the integron 5′CS region showed the presence of several known antibiotic resistance gene cassettes of various sizes. Results of conjugation and transformation experiments indicated that some of the ESBL-encoding genes (i.e. bla SHV, bla CTX-M and bla TEM-1) were transmissible and were likely plasmid-encoded. DNA fingerprinting using PFGE and PCR-based methods indicated that the 51 K. pneumoniae strains were genetically diverse and heterogeneous.

scholarly journals Molecular and Biochemical Characterization of CTX-M-131, a Natural Asp240Gly Variant Derived from CTX-M-2, Produced by a Providencia rettgeri Clinical Strain in São Paulo, Brazil

2015 ◽  
Vol 59 (3) ◽  
pp. 1815-1817 ◽  
Author(s):  
Milena Dropa ◽  
Barbara Ghiglione ◽  
Maria Helena Matté ◽  
Livia Carminato Balsalobre ◽  
Nilton Lincopan ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Clinical Strain ◽  
Class 1 Integron ◽  
Providencia Rettgeri ◽  
Content Type ◽  
Steady State Kinetic ◽  
Class 1 ◽  
Encoding Genes ◽  
State Kinetic

ABSTRACTCTX-M-131 is a natural Asp240Gly variant from the CTX-M-2 group detected in aProvidencia rettgericlinical strain from Brazil. Molecular analysis showed thatblaCTX-M-131was inserted in a complex class 1 integron harbored by a 112-kb plasmid, which has not been previously described as a platform for CTX-M-encoding genes with the Asp240Gly mutation. Steady-state kinetic parameters showed that the enzyme has a typical cefotaximase catalytic profile and an enhanced activity against ceftazidime.

scholarly journals Antimicrobial Susceptibility and Characterization of Salmonella Isolates from Processed Bison Carcasses

2006 ◽  
Vol 72 (4) ◽  
pp. 3046-3049 ◽  
Author(s):  
Qiongzhen Li ◽  
Jerod A. Skyberg ◽  
Mohamed K. Fakhr ◽  
Julie S. Sherwood ◽  
Lisa K. Nolan ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Gel Electrophoresis ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Cross Contamination ◽  
Class 1 Integron ◽  
Pulsed Field ◽  
Class 1

ABSTRACT Seventeen Salmonella enterica serovar Hadar isolates recovered from bison were found to possess a range of virulence genes and resistance to tetracycline, gentamicin, sulfamethoxazole, and streptomycin simultaneously. A 1-kb class 1 integron containing the aadA1 gene was identified in all isolates. Pulsed-field gel electrophoresis found that all isolates were closely related, indicating the possibility of cross-contamination during processing.

scholarly journals AAC(6′)-Iaf, a Novel Aminoglycoside 6′-N-Acetyltransferase from Multidrug-Resistant Pseudomonas aeruginosa Clinical Isolates

2009 ◽  
Vol 53 (6) ◽  
pp. 2327-2334 ◽  
Author(s):  
Tomoe Kitao ◽  
Tohru Miyoshi-Akiyama ◽  
Teruo Kirikae
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Decubitus Ulcer ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Upstream Region ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Class 1 ◽  
Layer Chromatography

ABSTRACT We report here the characterization of a novel aminoglycoside resistance gene, aac(6′)-Iaf, present in two multidrug-resistant (MDR) Pseudomonas aeruginosa clinical isolates. These isolates, IMCJ798 and IMCJ799, were independently obtained from two patients, one with a urinary tract infection and the other with a decubitus ulcer, in a hospital located in the western part of Japan. Although the antibiotic resistance profiles of IMCJ798 and IMCJ799 were similar to that of MDR P. aeruginosa IMCJ2.S1, which caused outbreaks in the eastern part of Japan, the pulsed-field gel electrophoresis patterns for these isolates were different from that for IMCJ2.S1. Both IMCJ798 and IMCJ799 were found to contain a novel chromosomal class 1 integron, In123, which included aac(6′)-Iaf as the first cassette gene. The encoded protein, AAC(6′)-Iaf, was found to consist of 183 amino acids, with 91 and 87% identity to AAC(6′)-Iq and AAC(6′)-Im, respectively. IMCJ798, IMCJ799, and Escherichia coli transformants carrying a plasmid containing the aac(6′)-Iaf gene and its upstream region were highly resistant to amikacin, dibekacin, and kanamycin but not to gentamicin. The production of AAC(6′)-Iaf in these strains was confirmed by Western blot analysis. Thin-layer chromatography indicated that AAC(6′)-Iaf is a functional acetyltransferase that specifically modifies the amino groups at the 6′ positions of aminoglycosides. Collectively, these findings indicate that AAC(6′)-Iaf contributes to aminoglycoside resistance.

scholarly journals Genetic characterization of multidrug resistance in Shigella spp. from Japan

2006 ◽  
Vol 55 (12) ◽  
pp. 1685-1691 ◽  
Author(s):  
Ashraf M. Ahmed ◽  
Kimi Furuta ◽  
Kei Shimomura ◽  
Yoshio Kasama ◽  
Tadashi Shimamoto
Keyword(s):  
Shigella Flexneri ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Shigella Sonnei ◽  
Sequencing Analysis ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Class 1 ◽  
Shigella Spp

This study characterized the genetic basis of antimicrobial resistance of a number of Shigella spp. isolated from humans from 2000 to 2004 in Hiroshima prefecture, Japan. A total of 26 isolates of Shigella spp. were included in this study. Antimicrobial susceptibility tests revealed high levels of resistance, especially to ampicillin, streptomycin, trimethoprim, tetracycline, nalidixic acid and ciprofloxacin. PCR and DNA sequencing were used for screening and characterization of antibiotic-resistance determinants. PCR sequencing analysis revealed the presence of only one type of class 1 integron in one isolate of Shigella sonnei. This class 1 integron was 1904 bp and contained two gene cassettes: a probable esterase/lipase (estX) and aadA1, which confers resistance to streptomycin and spectinomycin. Two types of class 2 integron were identified in this study. One was the classic type (2158 bp) and carried the three conserved resistance gene cassettes of the class 2 integron, dfrA1, sat1 and aadA1, which confer resistance to trimethoprim, streptothricin and streptomycin/spectinomycin, respectively. This type was detected in both Shigella sonnei (14 isolates) and Shigella flexneri (five isolates). The other type was shorter (1313 bp) and carried only two gene cassettes, dfrA1 and sat1. This integron was detected in a single isolate of Shigella sonnei. PFGE patterns showed limited diversity within clusters of the same species. Furthermore, an extended-spectrum β-lactamase gene, bla OXA-30, which confers resistance to ampicillin, was characterized in all isolates of Shigella flexneri except the oldest strain, which was isolated in 2000. Southern blot hybridization and conjugation experiments showed that bla OXA-30 was located in the chromosome.

scholarly journals Characterization of Multidrug Resistant ESBL-ProducingEscherichia coliIsolates from Hospitals in Malaysia

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
King-Ting Lim ◽  
Rohani Yasin ◽  
Chew-Chieng Yeo ◽  
Savithri Puthucheary ◽  
Kwai-Lin Thong
Keyword(s):  
Antibiotic Resistance ◽  
Random Amplified Polymorphic Dna ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Public Hospitals ◽  
Class 1 Integron ◽  
E Coli ◽  
Antibiotic Management ◽  
Class 1

The emergence ofEscherichia colithat produce extended spectrumβ-lactamases (ESBLs) and are multidrug resistant (MDR) poses antibiotic management problems. Forty-sevenE. coliisolates from various public hospitals in Malaysia were studied. All isolates were sensitive to imipenem whereas 36 were MDR (resistant to 2 or more classes of antibiotics). PCR detection using gene-specific primers showed that 87.5% of the ESBL-producingE. coliharbored theblaTEMgene. Other ESBL-encoding genes detected wereblaOXA,blaSHV, andblaCTX-M. Integron-encoded integrases were detected in 55.3% of isolates, with class 1 integron-encodedintI1integrase being the majority. Amplification and sequence analysis of the5′CS region of the integrons showed known antibiotic resistance-encoding gene cassettes of various sizes that were inserted within the respective integrons. Conjugation and transformation experiments indicated that some of the antibiotic resistance genes were likely plasmid-encoded and transmissible. All 47 isolates were subtyped by PFGE and PCR-based fingerprinting using random amplified polymorphic DNA (RAPD), repetitive extragenic palindromes (REPs), and enterobacterial repetitive intergenic consensus (ERIC). These isolates were very diverse and heterogeneous. PFGE, ERIC, and REP-PCR methods were more discriminative than RAPD in subtyping theE. coliisolates.

Molecular characterization of theblaKPC-2gene in clinical isolates of carbapenem-resistantKlebsiella pneumoniaefrom the pediatric wards of a Chinese hospital

2012 ◽  
Vol 58 (10) ◽  
pp. 1167-1173 ◽  
Author(s):  
Yang Liu ◽  
Xiang-Yang Li ◽  
La-Gen Wan ◽  
Wei-Yan Jiang ◽  
Fang-Qu Li ◽  
...  
Keyword(s):  
16S Rrna ◽  
Antibiotic Resistance Gene ◽  
Restriction Endonuclease Analysis ◽  
Multidrug Resistant ◽  
Class 1 Integron ◽  
Integrase Gene ◽  
Klebsiella Pneumoniae Carbapenemase ◽  
Class 1 ◽  
16S Rrna Methylase

The present study was conducted to confirm the presence of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae associated with a nosocomial outbreak in a Chinese pediatric hospital. From July 2009 to January 2011, 124 nonduplicated K. pneumoniae isolates were collected from specimens from patients of pediatric units in the hospital. Twelve of the 124 isolates possessed the blaKPC-2gene and showed 7 different pulsed-field gel electrophoresis (PFGE) patterns. Meanwhile, 16S rRNA methylase, acc(6′)-Ib-cr, and several types of β-lactamases were also produced by the majority of the KPC-producing isolates. Class 1 integron-encoded intI1 integrase gene was subsequently found in all strains, and amplification, sequencing, and comparison of DNA between 5′ conserved segment and 3′ conserved segment region showed the presence of several known antibiotic resistance gene cassettes of various sizes. The conjugation and plasmid-curing experiments indicated some KPC-2-encoding genes were transmissible. In addition, conjugal cotransfer of multidrug-resistant phenotypes with KPC-positive phenotypes was observed in KPC-producing strains. Restriction endonuclease analysis and DNA hybridization with a KPC-specific probe showed that the blaKPC-2gene was carried by plasmid DNA from K. pneumoniae of PFGE pattern B. The overall results indicate that the emergence and outbreak of KPC-producing K. pneumoniae in our pediatric wards occurred in conjunction with plasmids coharboring 16S rRNA methylase and extended-spectrum β-lactamases.

scholarly journals Occurrence and molecular characterization of metallo-β-lactamases (MBLs) among Acinetobacter baumannii isolates from cancer patients

10.3823/821 ◽  
2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Husam F. Qouzah ◽  
Feras Hawari ◽  
Luay F. Abu-Qatouseh ◽  
Asem A. Shehabi
Keyword(s):  
Acinetobacter Baumannii ◽  
Cancer Patients ◽  
Molecular Characterization ◽  
Wide Spectrum ◽  
Multidrug Resistant ◽  
Class 1 Integron ◽  
Class B ◽  
Class 1 ◽  
Resistant Infection

Background: During the last decade, the prevalence of carbapenem-resistant infection associated with multidrug resistant (MDR) Acinetobacter baumanniiin patients has been continuously increasing.  This prospective study aimed to determine the occurrence and molecular characterization of metallo-β-lactamases (MBLs) and carbapenem hydrolyzing oxacillinases among A. baumannii isolates from cancer patients over a period of 6-month. Methods:Antimicrobial susceptibility profile of 70 randomly collected A. baumannii isolates was first determined using disc diffusion test, and second, the MICs of 45 representative multidrug resistant (MDR) isolates were tested to useful drugs in treatment of their infections using E-test.  PCR assays were used to detect the common four types of class D carbapenem hydrolyzing oxacillinases, two types of class A carbapenemases, four types of class B metallo-β –lactamases, and prevalence of Class 1 Integron among MDR isolates. Results: All 70 isolates were MDR, including 100% resistance to meropenom, aztreonem, piperacillin/tazobactum and 99% to carbapenem.  All isolates carried blaOXA-23 and blaOXA-51, but none carried a blaOXA-24 like or blaOXA-58. The isolates also were positive for NDM-1, NDM, VIM, GES, KPC and SPM at the rates of 29%, 20%, 29%,19%,7% and 2%, respectively.  Class 1 Integron was positive in 82% of A. baumanniiisolates. The clonal relationship of 42 MDR A. baumanniiisolates using ERIC-PCR and constructed dendrogram showed 3 major genotype clusters of genetically related isolates. These include 4 genotype groups, each composed of 2 isolates with 100 % similarity of DNA bands.  Conclusion:This study demonstrates that A. baumannii colonize frequently cancer patients in association with antibiotic treatment. The organism is mostly carrying wide spectrum of antibiotic resistance genetic factors, especially many types of ESBLs and MBLs and Class 1 Integron. This fact should be considered when therapy is selected for treatment of patients infected with MDR A. baumannii. Key words. Acinetobacter baumannii, ESBLs, MBLs, Class 1 Integron, Jordanian cancer patients.  

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