GENOTYPIC DETECTION OF OXA 23 IN CARBAPENEM RESISTANT ACINETOBACTER BAUMANNII
Karim Abdelfattah Mahmoud Montasser;
Abstract
Acinetobacter spp. have emerged as one of the most important pathogens involved in health care associated infections in recent decades, characterized by their ability to accumulate different mechanisms of antimicrobial resistance, often showing a multidrug-resistant phenotype.
It is necessary to distinguish between Acinetobacter baumannii group and Acinetobacter outside the Acinetobacter baumannii group since the latter organisms rarely have infection control implications. In addition, these organisms are usually susceptible to a range of antimicrobials, and infections caused by these organisms are most often benign.
Acinetobacter baumanii is rapidly becoming a focus of significant attention, as it is the most frequent among Acientobacter species, responsible for ventilator-associated pneumonia and bloodstream infection which tend to be the most severe. Acinetobacter can also cause, skin and wound infections, urinary tract infection.
Carbapenems are considered important antimicrobial agents for treating infections due to multidrug-resistant Acinetobacter spp. However, reports of resistance to these drugs have emerged, with increasing frequency, among Acinetobacter spp. clinical isolates.
Modified Hodge test is a simple test which can be performed in the routine lab for detection of carbapenemases in isolates showing intermediate or sensitive zone diameter on disc diffusion. Methods for gene identification are polymerase chain reaction and DNA probing.
PCR has beeen successfully utilized for the detection of single or multiple carbapenemase genes directly from clinical samples. Obvious
Summary
advantages include a greater speed of detection and potentially a higher sensitivity than that offered by culture. Disadvantages include a higher cost for processing samples and the need for specialized equipment and/or expertise.
In this study, 172 isolates of Acinetobacter spp. isolated from clinical specimens submitted to Microbiology Central Laboratory of Ain Shams University Hospitals, were collected after antibiotic susceptibility testing was done. All isolates were imipenem-resistant. The isolates were subjected to API 20 NE identification system and modified Hodge test (MHT) for detection of carbapenemase producing strains.
According to the results of API 20 NE identification, 124 of the isolates were A. baumannii (72%) and 48 were A. loweffii (28%). Out of the 124 A. baumanni isolates.
According to the type of specimen, 68(39.5%) out of 172
Acinetobacter species were collected from sputum, classified into 44 (35.5%) out of 124 Acinetobacter baumannii isolates, and 24 (50%) out of 48 Acinetobacter Loweffii isolates. 50 (40%) out of 124 A. baumannii isolates were positive for MHT (carbapenemase producing), while 74 (60%) were negative (non carbapenemase producing). It was also detected that out of the 50 positive modified Hodge test Acinetobacter baumanii isolates with carbapenems resistance, 32 (64%) isolates were expressing OXA 23 gene.
Fluoroquinolones have remained active against sporadic Acinetobacter spp. strains but resistance is now widespread among epidemic Acinetobacter spp. strains, rendering these antimicrobial drugs no longer useful. Aminoglycosides, in particular tobramycin and amikacin, often
It is necessary to distinguish between Acinetobacter baumannii group and Acinetobacter outside the Acinetobacter baumannii group since the latter organisms rarely have infection control implications. In addition, these organisms are usually susceptible to a range of antimicrobials, and infections caused by these organisms are most often benign.
Acinetobacter baumanii is rapidly becoming a focus of significant attention, as it is the most frequent among Acientobacter species, responsible for ventilator-associated pneumonia and bloodstream infection which tend to be the most severe. Acinetobacter can also cause, skin and wound infections, urinary tract infection.
Carbapenems are considered important antimicrobial agents for treating infections due to multidrug-resistant Acinetobacter spp. However, reports of resistance to these drugs have emerged, with increasing frequency, among Acinetobacter spp. clinical isolates.
Modified Hodge test is a simple test which can be performed in the routine lab for detection of carbapenemases in isolates showing intermediate or sensitive zone diameter on disc diffusion. Methods for gene identification are polymerase chain reaction and DNA probing.
PCR has beeen successfully utilized for the detection of single or multiple carbapenemase genes directly from clinical samples. Obvious
Summary
advantages include a greater speed of detection and potentially a higher sensitivity than that offered by culture. Disadvantages include a higher cost for processing samples and the need for specialized equipment and/or expertise.
In this study, 172 isolates of Acinetobacter spp. isolated from clinical specimens submitted to Microbiology Central Laboratory of Ain Shams University Hospitals, were collected after antibiotic susceptibility testing was done. All isolates were imipenem-resistant. The isolates were subjected to API 20 NE identification system and modified Hodge test (MHT) for detection of carbapenemase producing strains.
According to the results of API 20 NE identification, 124 of the isolates were A. baumannii (72%) and 48 were A. loweffii (28%). Out of the 124 A. baumanni isolates.
According to the type of specimen, 68(39.5%) out of 172
Acinetobacter species were collected from sputum, classified into 44 (35.5%) out of 124 Acinetobacter baumannii isolates, and 24 (50%) out of 48 Acinetobacter Loweffii isolates. 50 (40%) out of 124 A. baumannii isolates were positive for MHT (carbapenemase producing), while 74 (60%) were negative (non carbapenemase producing). It was also detected that out of the 50 positive modified Hodge test Acinetobacter baumanii isolates with carbapenems resistance, 32 (64%) isolates were expressing OXA 23 gene.
Fluoroquinolones have remained active against sporadic Acinetobacter spp. strains but resistance is now widespread among epidemic Acinetobacter spp. strains, rendering these antimicrobial drugs no longer useful. Aminoglycosides, in particular tobramycin and amikacin, often
Other data
| Title | GENOTYPIC DETECTION OF OXA 23 IN CARBAPENEM RESISTANT ACINETOBACTER BAUMANNII | Other Titles | الكشف الوراثى لجين الأوكسا 23 فى بكتريا الأسنتوباكتر بومنباى المقاومة للكاربابينيم | Authors | Karim Abdelfattah Mahmoud Montasser | Issue Date | 2014 |
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