MOLECULAR CHARACTERIZATION OF GENES ENCODING ACQUIRED CARBAPENEMASE OF CARBAPENEMRESISTANT ACINETOBACTER BAUMANNII ISOLATES

2017 ◽  
pp. 52-57
Author(s):  
Nu Xuan Thanh Le ◽  
Thi Anh Ngoc Le ◽  
Thi Nam Lien Nguyen ◽  
Viet Quynh Tram Ngo ◽  
Santona Antonella ◽  
...  

Background: Today carbapenem-resistant A. baumannii isolates are rising in several parts of the world including Vietnam, they are recognized to be among the most difficult resistant bacteria to treat and control. Carbapenem resistance is most commonly caused by the production of OXA-type carbapenemases and metallo-β-lactamases (MBLs). Objectives: Determine the rate and detect the genes encoding acquired carbapenemase of carbapenem-resistant A. baumannii isolates. Materials and methods: Study design is cross-sectional descriptive study. Carbapenem-resistant A. baumannii isolates in 90 A. baumannii (ACB) complex isolates were collected from Hue Central Hospital (HCH) and Hue University Hospital (HUP). Susceptibility to carbapenem of A. baumannii strains were performed by MicroScan method. Multiplex PCRs were performed to detect the genes encoding acquired carbapenemase. Results: Carbapenem resistance rates in A. baumannii were 88.5% and 87.5% in HCH and HHUMP, respectively. All of genes blaOXA-51, blaOXA-23, blaOXA-58, blaIMP, blaNDM as well as coexistence of two genes (blaIMP, blaNDM) or three genes ((blaOXA-51, blaOXA-23, blaOXA-58) or (blaIMP, blaNDM, blaOXA-58)) were detected in carbapenem resistant A. baumannii isolates. Conclusions: Carbapenem resistance rate in A. baumannii was relatively high. The emergence of carbapenem resistance in A. baumannii is associated with the production of OXA-type carbapenemases and metallo-β-lactamases (MBLs). Key words: Acinetobacter baumannii; carbapenem resistance; carbapenemase

2021 ◽  
Vol 71 (11) ◽  
pp. 2576-2581
Author(s):  
Saima Ishtiaq ◽  
Sidrah Saleem ◽  
Abdul Waheed ◽  
Arslan Ahmed Alvi

Objective: To evaluate carbapenem resistance and to detect blaOXA-23 and blaOXA-51 genes in carbapenem-resistant acinetobacter baumanii isolates recovered from patients having pneumonia secondry to ventilation. Methods: The cross-sectional study was conducted from July 2017 to June 2018 at the Department of Microbiology, University of Health Sciences, Lahore, Pakistan, and comprised endotracheal aspirates / tracheobroncheal lavage samples from patients irrespective of age and gender who developed pneumonia after being on the ventilator for 48 hrs at the Combined Military Hospital, and Jinnah Hospital, Lahore.  The samples were inoculated on MacConkey and blood agar and aerobically incubated at a temperature of 370C for 18-24 hours. The isolated organisms were further assessed by standard morphological, cultural and biochemical profile. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method. Carbapenem-resistant acinetobacter baumannii were checked for carbapenemase production using Modified Hodge Test. Conventional polymerase chain reaction and agarose gel electrophoreses were performed to detect blaOXA-23 and blaOXA-51 genes. Data was analysed using SPSS 17. Results: Out of 157 samples, 92(58.6%) yielded growth of bacteria, and, among them, 39(42.4%) were identified as acinetobacter baumannii. All (100%) acinetobacter baumannii cases showed resistance to carbapenem, were producing carbapenemase enzyme, and were positive for blaOXA-51 gene. The blaOXA-23 gene was amplified in 38(97.4%) isolates. Conclusion: BlaOXA-23 gene appeared to be the major cause of carbapenem resistance. Continuous...


2006 ◽  
Vol 27 (7) ◽  
pp. 759-761 ◽  
Author(s):  
Anton Y. Peleg ◽  
Clare Franklin ◽  
Jan M. Bell ◽  
Denis W. Spelman

We describe the first emergence of carbapenem-resistantAcinetobacter baumanniiin Australia. NinetyA. baumanniiisolates recovered from cultures of blood specimens from 69 patients were analyzed. Overall, 58 isolates (64%) were resistant to meropenem. The χ2test for linear trend revealed that emergence of carbapenem resistance was statistically significant during the 32-month study period. Selected isolates were of the same clonal type, and no genes encoding carbapenemases were identified.


2021 ◽  
Vol 10 (14) ◽  
pp. 1039-1041
Author(s):  
Swathi Gurajala ◽  
Sandeep Kumar Tipparthi ◽  
Rajkumar H.R.V.

Bacteria develop antimicrobial drug resistance through several mechanisms, the common one being the production of enzymes. As the number of antibiotics discovered is in notable numbers in the past few years, it is important to preserve high-end antibiotics for the treatment of multidrug-resistant organisms (MDROs) infections, by appropriate use of antibiotics. A study was conducted to record prevalence, phenotypic and genotypic characters of MDROs in our hospital, with reference to carbapenem resistance. 200 multidrug-resistant clinical isolates were collected in 6 months. Carbapenem-resistant organisms were detected phenotypically confirmed for the production of carbapenemases by modified Hodge test (MHT) and genotypic detection was done by a multiplex polymerase chain reaction (PCR) assay for the five most predominant carbapenemases (bla NDM-1, bla OXA-48 , bla VIM, bla IMP, bla KPC). The isolates consisted of E. coli (53 %) followed by K. pneumoniae (30 %), P. aeruginosa (13 %), and acinetobacter spp (4 %). Among these, 40 (20 %) isolates were carbapenem-resistant. Of these 40, 27 (67.5 %) showed an increase in zone size by the MHT, suggestive of metallo-beta-lactamase (MBL) mediated carbapenem resistance and about 32 (80 %) isolates were found to contain at least one carbapenemase gene. bla NDM-1 accounted for 37.5 % (12 / 32) of the isolates and was the most predominant one followed by bla OXA-48 [28 % (9 / 32)]. 22 % (7 / 32) of the isolates had one or more carbapenemase genes. Identifying the mechanisms of resistance of pathogens is important to implement strict infection prevention and control measures in the hospital to prevent the transmission of the resistant pathogens. KEY WORDS Multidrug-Resistant Bacteria, Bla NDM-1 Gene, Bla OXA-48 Gene, Carbapenem Resistance, Carbapenem Resistant Organisms.


Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Vitus Silago ◽  
Eveline C. Mruma ◽  
Betrand Msemwa ◽  
Conjester I. Mtemisika ◽  
Shukurani Phillip ◽  
...  

Data on colonization and hospital contamination of carbapenem-resistant Gram-negative bacteria (CR-GNB) are limited in low- and middle-income countries. We designed this study to determine the prevalence and co-existence of carbapenemase genes among CR-GNB isolated from clinical, colonization, and hospital environmental samples at a tertiary hospital in Mwanza, Tanzania. The modified Hodge test (MHT), the combined disk test (CDT), and the double-disk synergy test (DDST) were used for the phenotypic detection of carbapenemases. A multiplex PCR assay was used to detect blaIMP and blaKPC, and a singleplex PCR assay was used to detect blaOXA-48. Data were analyzed by STATA version 13.0. Overall, 68.8% (44/64) of the CR-GNB had at least one phenotype by phenotypic methods, whereby 60.9% (39/64) were both CDT and DDST positive and 31.3% (20/64) were MHT positive. A total of 23/64 (35.9%) had at least one of the genes tested with the predominance of blaIMP (91.3%; 21/23). In addition, 47.7% (21/44) of the CR-GNB phenotypes had at least one gene. Around 47.8% (11/23) of the CR-GNB carried multiple genes encoding for carbapenem resistance, with the maximum co-existence of blaIMP/blaKPC/blaOXA-48 (45.5%; 5/11). The majority of carbapenem-resistant genes were detected in Acinetobacter spp. (82.6%; 19/23) and isolated from bed swabs (69.6%; 16/23). Acinetobacter spp. carrying the blaIMP gene predominantly contaminated the hospital environment. Therefore, we recommend routine decontamination of inanimate hospital surfaces, including patient beds.


2020 ◽  
Vol 67 (3) ◽  
pp. 182-186
Author(s):  
Susan Khanjani ◽  
Hadi Sedigh Ebrahim-Saraie ◽  
Mohammad Shenagari ◽  
Ali Ashraf ◽  
Ali Mojtahedi ◽  
...  

AbstractThis study was aimed to evaluate occurrence of antibiotic resistance and the presence of resistance determinants among clinical isolates of Acinetobacter baumannii. This cross-sectional study from January to September 2018 was performed on 59 A. baumannii strains isolated from clinical samples in the north of Iran. Isolates were identified by standard microbiologic tests and molecular method. Antimicrobial susceptibility testing was carried out by disk diffusion and broth microdilution methods. The presence of carbapenem resistance genes was detected by PCR method. All isolates were resistant to cefepime, meropenem, imipenem and ceftazidime. The lowest resistance rate was observed against doxycycline with 33.9%. Minimum inhibitory concentration (MIC) results showed that all carbapenem-resistant A. baumannii (CRAB) isolates were susceptible to colistin with MIC50 and MIC90 values of 1/2 µg/mL. Among 59 CRAB, blaOXA-23-like was the most prevalent gene (86.4%) followed by blaOXA-24-like (69.5%). Meanwhile, none of the clinical isolates harbored blaOXA-58-like gene. We found a high prevalence of CRAB strains harboring OXA-type carbapenemases in the north of Iran. Our results suggests that the presence of OXA-type genes was not directly correlated with the increase of imipenem MIC level, but can be clinically important as they contribute to the selection of CRAB strains.


2008 ◽  
Vol 57 (12) ◽  
pp. 1529-1532 ◽  
Author(s):  
Deniz Gur ◽  
Volken Korten ◽  
Serhat Unal ◽  
Lalitagauri M. Deshpande ◽  
Mariana Castanheira

A significant increase in carbapenem-resistance rates among Acinetobacter baumannii isolates collected in two Turkish medical centres was detected in the 2000–2006 period (20–60 %) by the SENTRY Antimicrobial Surveillance Program. Carbapenem-resistant strains from 2006 were evaluated for the presence of encoding genes and epidemic clonality. OXA-58-like and OXA-23-like carbapenemase-producing strains were detected in both medical institutions. Seventeen out of 18 strains from Ankara were positive for bla OXA-58 primers and belonged to the same clone, whilst 26 isolates (25 from Istanbul and one from Ankara) harboured bla OXA-23-like genes and showed identical or similar PFGE patterns. Isolates producing OXA-23-like carbapenemases were more resistant than OXA-58-like carbapenemase producers to non-carbapenem antimicrobial agents. Carbapenem resistance in these institutions was observed to be largely driven by the dissemination of clones producing OXA-type carbapenemases.


2020 ◽  
Vol 41 (S1) ◽  
pp. s398-s398
Author(s):  
Tuan Huynh ◽  
Vasquez Amber ◽  
Lan Pham ◽  
Loan Luong ◽  
Tuan Le ◽  
...  

Background: Carbapenem-resistant gram-negative bacteria are an urgent threat to healthcare safety around the world. In Vietnam, Although surveillance and control of multidrug-resistant organisms is a national priority, information on the burden of these resistant pathogens is still scarce. At University Medical Center Ho Chi Minh City, Vietnam, we aimed to better understand carbapenem-resistance through 2 phases: (1) assess proportion of carbapenem-resistant gram-negative organisms that are carbapanemase-producing (CP-CRO) and (2) assess transmission burden of carbapenemase-producing carbapenem-resistant Enterobacterieacea (CP-CRE) in the general intensive care unit (ICU). Methods: In the first phase, all gram-negative clinical isolates collected between November 2018 and April 2019 were tested for carbapenem-resistance using the disc-diffusion method and were defined as meropenem resistant using the Clinical and Laboratory Standards Institute 2018 break point (M100-Performance Standards for Antimicrobial Susceptibility Testing, 28th Edition). Carbapenem-resistant bacteria were tested for phenotypic carbapenemase-production using the Becton Dickinson Phoenix CPO Detect assay. In the second phase, we instituted CP-CRE rectal screening using CHROMagar mSuperCARBA media for all ICU patients from July through September 2019. Patients were screened on admission, and negative patients were rescreened every 2 days until discharge, death, or CRE-positive screening or culture. Admission prevalence and incidence of CP-CRE transmission was calculated among CP-CRE infected or colonized patients. Results: From November 2018 through April 2019, 599 gram-negative clinical isolates from 543 patient samples were identified. Of these, 108 were carbapenem-resistant; 107 (99%) of carbapenem-resistant isolates were carbapenemase-producing by phenotypic method. Most CP-CRO were Acinetobacter baumannii (45 of 107, 42%) or Klebsiella pneumoniae (39 of 107, 36%). During ICU CP-CRE colonization screening, the July positivity rate on admission was 40% (32 of 81), the August positivity rate on admission was 30% (21 of 71), and the September positivity rate on admission was 40% (30 of 75). Of those with negative admission screen, the proportion of new CP-CRE colonization in July was 45% (22 of 49), the proportion of new CP-CRE colonization in August was 64% (32 of 50), and the proportion of new CP-CRE colonization in September was 44% (20 of 45). Across all 3 months of screening, the proportions of CP-CRE that were Klebsiella, Citrobacter, or Enterobacter were 68% (118 of 174) and the proportion of CP-CRE that were Eschericia coli was 37% (56 of 174). The average number of days to turn from negative to positive screening result was 4.1. Conclusions: Our analysis demonstrates that nearly all carbapenem-resistant organisms at our hospital are carbapenemase producing. In the ICU, we identified a high burden of CP-CRE, attributable to high presence on admission and new acquisition in the ICU. An intervention package based on CDC-recommended enhanced infection control measures is being implemented to decrease CP-CRE transmission in the ICU.Funding: NoneDisclosures: None


Author(s):  
Abolfazl Vahhabi ◽  
Alka Hasani ◽  
Mohammad Ahangarzadeh Rezaee ◽  
Behzad Baradaran ◽  
Akbar Hasani ◽  
...  

Background and Objectives: Carbapenem treatment for Acinetobacter baumannii infections presently faces threats owing to the production of several types of carbapenemase enzymes, prevalence of which varies among different countries. We explored the current trend of antibiotic resistance in A. baumannii clinical isolates from North West Iran, sought the mechanism of carbapenem resistance and addressed the sequence type groups in carbapenem resistant A. baumannii (CRAB). Materials and Methods: A. baumannii (n=112) isolates were recovered from various clinical specimens of patients admitted in internal, surgery, burn, infectious diseases and various ICUs wards. Genetically confirmed A. baumannii isolates were screened for carbapenem resistance by the Kirby-Bauer and E-test and the presence of bla PCR. Sequence groups were identified by multiplex PCR. Results: Multidrug-resistance (MDR) was a characteristic feature of all A. baumannii isolates. Frequency of oxacillinase genes in combination including blaOXA-51-like/blaOXA-23-like, blaOXA-51-like OXA-24/40-like and blaOXA-51-like/blaOXA-23-like/blaOXA-24/40-like was 82.1%, 36.6% and 25.8% respectively. Blending of oxacillinase and MBL genes was evident in eight bla positive and 7 blaOXA-24-like positive isolates thereby depicting synchronous etiology of carbapenem resistance. Amongst CRAB isolates, 97.3% contained ISAba1 element and 50.9% belonged to the European clone II. Conclusion: Synchronicity among blaOXA-like with bla and ISAba1 gene was a hallmark of this investigation. Though origin or route of transmission was not elucidated in this study but co-existence among OXA and MBL producing genes is a therapeutic concern demanding strict surveillance strategies and control programs to halt the dissemination of these isolates in the hospital setting.


2014 ◽  
Vol 8 (01) ◽  
pp. 044-049 ◽  
Author(s):  
Murat Dizbay ◽  
Ozlem Guzel Tunccan ◽  
Omer Karasahin ◽  
Firdevs Aktas

Introduction:Risk factors for nosocomial carbapenem-resistant Klebsiella spp. (CRK) infections were analyzed in this study.Methodology:The incidence, clinical characteristics, risk factors, antimicrobial susceptibility, and outcomes of CRK infections during a seven-year period (2004-2010) were retrospectively analyzed.Results:A total of 720 patients were included in the study. Carbapenem resistance among Klebsiella spp. were significantly increased between 2003 and 2007 (p<0.001). CRK strains were mostly isolated from ICUs (p<0.001). Use of imipenem and cefoperazone-sulbactam within prior three months, stay in ICU, receiving immunspressive therapy, receiving H2 receptor antagonists, tracheostomy, mechanical ventilation, hemodialysis, urinary catheter were found to be significant risk factors for carbapenem resistance Klebsiella spp. infections. In a multivariate analysis, prior use of imipenem (OR 3.35; CI 1.675-6.726, p<0.001), stay in ICU (OR 3.36; 95% CI 1.193-9.508; p=0.022), receiving H2 receptor antagonist (OR 4.49; 95% CI 1.011-19.951; p=0.048) were independently associated with carbapenem resistance. Respiratory tract infections were the most seen nosocomial infection. Attack mortality rate was significantly higher in patients infected with CRK strains (p<0.001). CRK strains showed significantly higher resistance rates to other antibiotics.Conclusions:In conclusion, the emergence and rapid spread of CRK strains in our hospital is worrisome. The patients in ICU are most important risk group for the acquisition of CRK strains. High resistant rates to other antibiotics except than colistin and tigecycline limits therapeutic options, and increases mortality rates.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Patrick Chhatwal ◽  
Ella Ebadi ◽  
Frank Schwab ◽  
Stefan Ziesing ◽  
Ralf-Peter Vonberg ◽  
...  

Abstract Background Carbapenem resistant (CR) Klebsiella pneumoniae (Kp) and Acinetobacter baumannii (Ab) are emerging multidrug resistant bacteria with very limited treatment options in case of infection. Both are well-known causes of nosocomial infections and outbreaks in healthcare facilities. Methods A retrospective study was conducted to investigate the epidemiology of inpatients with CR Kp and CR Ab in a 1500-bed German university hospital from 2015 to 2019. We present our infection control concept including a weekly microbiologic screening for patients who shared the ward with a CR Kp or CR Ab index patient. Results Within 5 years, 141 CR Kp and 60 CR Ab cases were hospitalized corresponding to 118 unique patients (74 patients with CR Kp, 39 patients with CR Ab and 5 patients with both CR Ab and CR Kp). The mean incidence was 0.045 (CR Kp) and 0.019 (CR Ab) per 100 inpatient cases, respectively. Nosocomial acquisition occurred in 53 cases (37.6%) of the CR Kp group and in 12 cases (20.0%) of the CR Ab group. Clinical infection occurred in 24 cases (17.0%) of the CR Kp group and in 21 cases (35.0%) of the CR Ab group. 14 cases (9.9%) of the CR Kp group and 29 cases (48.3%) of the CR Ab group had a history of a hospital stay abroad within 12 months prior to admission to our hospital. The weekly microbiologic screening revealed 4 CR Kp cases caused by nosocomial transmission that would have been missed without repetitive screening. Conclusions CR Kp and CR Ab cases occurred infrequently. A history of a hospital stay abroad, particularly in the CR Ab group, warrants pre-emptive infection control measures. The weekly microbiologic screening needs further evaluation in terms of its efficiency.


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