2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia
| Format: | General Document |
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| collectionurl | https://intelek.unisza.edu.my/intelek/pages/search.php?search=!collection3 |
| copyright | Copyright©PWB2025 |
| country | Malaysia |
| date | 2018-02-04 |
| format | General Document |
| id | 15482 |
| institution | UniSZA |
| internalnotes | Sila masukkan subject wajib Dissertations, Academic. Terima kasih... |
| originalfilename | ISOLATION AND CHARACTERISATION OF ACINETOBACTER SPECIES CLINICAL ISOLATES FROM TERENGGANU, MALAYSIA (MASTER_2018).pdf |
| person | Farahiyah Mohd Rani |
| recordtype | oai_dc |
| resourceurl | https://intelek.unisza.edu.my/intelek/pages/view.php?ref=15482 |
| sourcemedia | Server storage Scanned document |
| spelling | 15482 https://intelek.unisza.edu.my/intelek/pages/view.php?ref=15482 https://intelek.unisza.edu.my/intelek/pages/search.php?search=!collection3 General Document Malaysia Library Staff (Top Management) Library Staff (Management) Library Staff (Support) Terengganu Faculty of Medicine English application/pdf 20 1.7 Server storage Scanned document Universiti Sultan Zainal Abidin UniSZA Private Access Universiti Sultan Zainal Abidin PDFium ISOLATION AND CHARACTERISATION OF ACINETOBACTER SPECIES CLINICAL ISOLATES FROM TERENGGANU, MALAYSIA (MASTER_2018).pdf 2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia Copyright©PWB2025 Farahiyah Mohd Rani 2018-02-04 Acinetobacter—Isolation & Purification Acinetobacter spp. have become one of the top nosocomial pathogens of concern causing a wide spectrum of infections including bloodstream, urinary and respiratory tract. Increasing prevalence of multidrug resistance (MDR-resistance to three or more antimicrobial group) has become a very serious health concern among Acinetobacter spp., particularly carbapenem resistance.Acinetobacter spp. is difficult to identify to the species level using standard biochemical and phenotypic tests. Hence, there is a lack of data regarding the prevalence of drug resistance among A. baumannii (which is the main Acinetobacter species causing serious infections) and non-baumannii Acinetobacter species in Malaysia. This study aims to characterize Acinetobacter spp. isolates from Terengganu, Malaysia, particularly their drug resistance profiles and carriage of resistance genes. One hundred and fifty-three Acinetobacter spp. isolates were collected from the microbiology laboratory of Hospital Sultanah Nur Zahirah (HSNZ) in Kuala Terengganu throughout 2015. All isolates were initially differentiated into A. baumannii and non-baumannii Acinetobacter spp. by amplification of 16S ribosomal DNA restriction analysis (ARDRA) with five different restriction enzymes (HhaI, AluI, MboI, RsaI, and MspI). Identification of the non baumannii acinetobacters at the species level was performed by sequencing of ribosomal polymerase beta subunit (rpoB) and16S ribosomal ribonucleic acid (16S rRNA) genes. Antibiotic susceptibility tests were performed with 16 antimicrobial agents by the disc diffusion method. The minimum inhibitory concentration for imipenem, meropenem, and tigecycline were determined using E-strips. The isolates were also screened for the presence of six main carbapenem-resistance genes (intrinsic blaOXA-51, acquired blaOXA-23, blaOXA-24, blaOXA-58, blaVIM, and blaIMP) by polymerase chain reaction (PCR). The upstream of ISAba1 towards blaOXA-51 and blaOXA-23 genes were also investigated by PCR detection. ARDRA revealed that 83.7% (n=128) of the isolates were Acinetobacter baumannii while the rest were grouped as non-baumannii genospecies. The rate of MDR among all Acinetobacter spp. isolates was 56.2% (n=86) with a vast majority (98%; n=85) being A. baumannii. Overall, the isolates showed moderate resistance rates (between 60%-70%) to amikacin, gentamicin, imipenem, meropenem, doripenem, ciprofloxacin, piperacillin tazobactam, ticarcillin-clavulanate, cefotaxime, cefuroxime, ceftazidime, cefepime, ampicillin-sulbactam, and tetracycline. All isolates were susceptible to polymyxin B, colistin, and tigecycline, considered the drugs of last resort for carbapenem-resistant Acinetobacter infections. Carbapenem resistance rates were higher among A. baumannii (68.8%) as compared to non-baumannii Acinetobacter isolates (8.0%). Screening for carbapenemase-encoding genes by PCR revealed that 98% of the isolates harboured the blaOXA-51 gene, 56.2% harboured blaOXA-23, 4.6% with blaOXA 24, and 2% carried blaOXA-58 gene. A. baumannii isolates harbouring ISAbaI-blaOXA-23 (70.5%) were significantly associated with resistance towards carbapenems (p<0.001), due likely to the ISAbaI element providing an external promoter for the increased expression of the blaOXA-23 gene. The acquired blaOXA-23 gene was largely responsible for carbapenem resistance in the clinical A. baumannii isolates from HSNZ and warrants continuous surveillance to prevent its further dissemination. The existence of a small number of non-baumannii Acinetobacter clinical isolates should be closely monitored and antimicrobial drug usage in the hospital carefully controlled to prevent the development and spread of MDR strains of both A. baumannii and other distinctive non-baumannii Acinetobacter genospecies. Dissertations, Academic Sila masukkan subject wajib Dissertations, Academic. Terima kasih... Acinetobacter Species Clinical Bacterial Isolates Bacterial Characterization Thesis |
| spellingShingle | 2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia |
| state | Terengganu |
| subject | Acinetobacter—Isolation & Purification Dissertations, Academic |
| summary | Acinetobacter spp. have become one of the top nosocomial pathogens of concern causing a wide spectrum of infections including bloodstream, urinary and respiratory tract. Increasing prevalence of multidrug resistance (MDR-resistance to three or more antimicrobial group) has become a very serious health concern among Acinetobacter spp., particularly carbapenem resistance.Acinetobacter spp. is difficult to identify to the species level using standard biochemical and phenotypic tests. Hence, there is a lack of data regarding the prevalence of drug resistance among A. baumannii (which is the main Acinetobacter species causing serious infections) and non-baumannii Acinetobacter species in Malaysia. This study aims to characterize Acinetobacter spp. isolates from Terengganu, Malaysia, particularly their drug resistance profiles and carriage of resistance genes. One hundred and fifty-three Acinetobacter spp. isolates were collected from the microbiology laboratory of Hospital Sultanah Nur Zahirah (HSNZ) in Kuala Terengganu throughout 2015. All isolates were initially differentiated into A. baumannii and non-baumannii Acinetobacter spp. by amplification of 16S ribosomal DNA restriction analysis (ARDRA) with five different restriction enzymes (HhaI, AluI, MboI, RsaI, and MspI). Identification of the non baumannii acinetobacters at the species level was performed by sequencing of ribosomal polymerase beta subunit (rpoB) and16S ribosomal ribonucleic acid (16S rRNA) genes. Antibiotic susceptibility tests were performed with 16 antimicrobial agents by the disc diffusion method. The minimum inhibitory concentration for imipenem, meropenem, and tigecycline were determined using E-strips. The isolates were also screened for the presence of six main carbapenem-resistance genes (intrinsic blaOXA-51, acquired blaOXA-23, blaOXA-24, blaOXA-58, blaVIM, and blaIMP) by polymerase chain reaction (PCR). The upstream of ISAba1 towards blaOXA-51 and blaOXA-23 genes were also investigated by PCR detection. ARDRA revealed that 83.7% (n=128) of the isolates were Acinetobacter baumannii while the rest were grouped as non-baumannii genospecies. The rate of MDR among all Acinetobacter spp. isolates was 56.2% (n=86) with a vast majority (98%; n=85) being A. baumannii. Overall, the isolates showed moderate resistance rates (between 60%-70%) to amikacin, gentamicin, imipenem, meropenem, doripenem, ciprofloxacin, piperacillin tazobactam, ticarcillin-clavulanate, cefotaxime, cefuroxime, ceftazidime, cefepime, ampicillin-sulbactam, and tetracycline. All isolates were susceptible to polymyxin B, colistin, and tigecycline, considered the drugs of last resort for carbapenem-resistant Acinetobacter infections. Carbapenem resistance rates were higher among A. baumannii (68.8%) as compared to non-baumannii Acinetobacter isolates (8.0%). Screening for carbapenemase-encoding genes by PCR revealed that 98% of the isolates harboured the blaOXA-51 gene, 56.2% harboured blaOXA-23, 4.6% with blaOXA 24, and 2% carried blaOXA-58 gene. A. baumannii isolates harbouring ISAbaI-blaOXA-23 (70.5%) were significantly associated with resistance towards carbapenems (p<0.001), due likely to the ISAbaI element providing an external promoter for the increased expression of the blaOXA-23 gene. The acquired blaOXA-23 gene was largely responsible for carbapenem resistance in the clinical A. baumannii isolates from HSNZ and warrants continuous surveillance to prevent its further dissemination. The existence of a small number of non-baumannii Acinetobacter clinical isolates should be closely monitored and antimicrobial drug usage in the hospital carefully controlled to prevent the development and spread of MDR strains of both A. baumannii and other distinctive non-baumannii Acinetobacter genospecies. |
| title | 2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia |
| title_full | 2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia |
| title_fullStr | 2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia |
| title_full_unstemmed | 2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia |
| title_short | 2018_Isolation and Characterisation of Acinetobacter Species Clinical Isolates from Terengganu, Malaysia |
| title_sort | 2018_isolation and characterisation of acinetobacter species clinical isolates from terengganu, malaysia |