Browsing by Author "Rasslan, Fatma"

Now showing 1 - 2 of 2

Co-Existence of Carbapenemase-Encoding Genes in Acinetobacter baumannii from Cancer Patients
(ADIS, 11/12/2020) Wasfi, Reham; Rasslan, Fatma; Hassan, Safaa S.; Ashour, Hossam M.; Abd El-Rahman, Ola A.
Introduction: Acinetobacter baumannii is an opportunistic pathogen, which can acquire new resistance genes. Infections by carbapenem-re- sistant A. baumannii (CRAB) in cancer patients cause high mortality. Methods: CRAB isolates from cancer patients were screened for carbapenemase-encoding genes that belong to Ambler classes (A), (B), and (D), followed by genotypic characterization by enterobacterial-repetitive-Intergenic- consensus–polymerase chain reaction (ERIC–PCR) and multilocus-sequence-typing (MLST). Results: A total of 94.1% of CRAB isolates co- harbored more than one carbapenemase-en- coding gene. The genes blaNDM, blaOXA-23-like, and blaKPC showed the highest prevalence, with rates of 23 (67.7%), 19 (55.9%), and 17 (50%), respectively. ERIC-PCR revealed 19 patterns (grouped into 9 clusters). MLST analysis identi- fied different sequence types (STs) (ST-268, ST- 195, ST-1114, and ST-1632) that belong to the highly resistant easily spreadable International clone II (IC II). Genotype diversity indicated the dissemination of carbapenem-hydrolyzing, b-lactamase-encoding genes among genetically unrelated isolates. We observed a high preva- lence of metallo-b-lactamase (MBL)-encoding genes (including the highly-resistant blaNDM gene that is capable of horizontal gene transfer) and of isolates harboring multiple carbapene- mase-encoding genes from different classes. Conclusion: The findings are alarming and call for measures to prevent and control the spread of MBL-encoding genes among bacteria causing infections in cancer patients and other immunocompromised patient populations.
The RND Efflux Pump Gene Expression in the Biofilm Formation of Acinetobacter baumannii
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-02) Abd El-Rahman, Ola A; Rasslan, Fatma; Hassan, Safaa S; Ashour, Hossam M; Wasfi, Reham
Multidrug resistant (MDR) Acinetobacter baumannii is a critical opportunistic pathogen in healthcare-associated infections (HAI). This is attributed to several factors, including its ability to develop biofilms that can enhance antimicrobial resistance (AMR) in addition to creating an environment for horizontal transfer of antibiotic resistance genes. The role of the efflux pump in biofilm formation is important for studies on alternative treatments for biofilms. One of the significant efflux pump families is the RND efflux pump family, which is common in Gram negative bacteria. The aim is to study the role of the RND efflux pump in biofilm formation by A. baumannii. The biofilm formation potential of thirty-four MDR A. baumannii isolates was evaluated by crystal violet assays. The effect of efflux pump inhibition and activation was studied using the efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and the RND efflux pump substrate levofloxacin (at sub-MIC), respectively. The isolates were genotypically grouped by enterobacterial repetitive intergenic consensus (ERIC) typing and the expression of adeABC, adeFGH, and adeIJK efflux pump genes was measured by qPCR. Overall, 85.2% (29/34) of isolates were biofilm producers (the phenotype was variable including strong and weak producers). Efflux pump inhibition by CCCP reduced the biofilm formation significantly (p < 0.05) in 20.5% (7/34) of some isolates, whereas sub-MICs of the substrate levofloxacin increased biofilm formation in 17.6% (6/34) of other isolates. Overexpression of the three RND efflux pump genes was detected in five out of eleven selected isolates for qPCR with remarkable overexpression in the adeJ gene. No correlation was detected between the biofilm phenotype pattern and the RND efflux pump gene expression in biofilm cells relative to planktonic cells. In conclusion, the role of the RND efflux pumps AdeABC, AdeFGH, and AdeIJK in biofilm formation does not appear to be pivotal and the expression differs according to the genetic background of each strain. Thus, these pumps may not be a promising target for biofilm inhibition.