Biofilm-Formation in Clonally Unrelated Multidrug-Resistant Acinetobacter baumannii Isolates
Authors: Alamri, Aisha M.; Alsultan, Afnan A.; Ansari, Mohammad A.; Alnimr, Amani M.
This study analyzed the genotype, antibiotic resistance, and biofilm formation ofAcinetobacter baumanniistrains and assessed the correlation between biofilm formation, antibiotic resistance, and biofilm-related risk factors. A total of 207 non-replicate multi-drug-resistantA. baumanniistrains were prospectively isolated. Phenotypic identification and antimicrobial susceptibility testing were carried out. Isolate biofilm formation ability was evaluated using the tissue culture plate (TCP), Congo red agar, and tube methods. Clonal relatedness between the strains was assessed by enterobacterial repetitive intergenic consensus-PCR genotyping. Of the 207 isolates, 52.5% originated from an intensive care unit setting, and pan resistance was observed against ceftazidime and cefepime, with elevated resistance (99-94%) to piperacillin/tazobactam, imipenem, levofloxacin, and ciprofloxacin. alongside high susceptibility to tigecycline (97.8%). The Tissue culture plate, Tube method, and Congo red agar methods revealed that 53.6%, 20.8%, and 2.7% of the strains were strong biofilm producers, respectively, while a significant correlation was observed between biofilm formation and device-originating respiratory isolates (p= 0.0009) and between biofilm formation in colonized vs. true infection isolates (p= 0.0001). No correlation was detected between antibiotic resistance and biofilm formation capacity, and the majority of isolates were clonally unrelated. These findings highlight the urgent need for implementing strict infection control measures in clinical settings.
Diabetes and multidrug-resistance gene mutation: tuberculosis in Zunyi, Southwest China
ANNALS OF PALLIATIVE MEDICINE
Authors: Lin, Mu; Liao, Jiangrong; Gong, Yadong; Han, Xiaojing; Chen, Yunhua; Tang, Zhu; Ma, Qingqing
Background: The aim of this study was to clarify the characteristics of gene mutation related to multi drug-resistance (MDR) of tuberculosis (TB) and diabetes in Zunyi. Methods: A total 763 patients with TB, were screened for TB-DNA, TB-RNA, and acid-fast staining (all were positive). They were divided into the tuberculosis (TB) group and the diabetes mellitus-tuberculosis (DM-TB) group. We compared and analyzed the MDR gene rpoB, KatG, and inhA characteristics of gene mutations in the two groups by polymerase chain reaction (PCR)-reverse dot hybridization, and collected relevant clinical data to explore its correlation with the occurrence of multidrug resistance. Results: Multidrug resistance occurred in 32 of the 525 patients in the TB group, and extensive drug resistance occurred in 15 of the 207 patients in the DM-TB group. In the DM-TB group, the mutation rates of ropBS53 1L and ropB531 (both 53.33%) were lower than those of the TB group (both 59.38%) in rifampicin resistance mutations. Most of the mutations were at the KatG3 15N site, conferring isoniazid resistance. Conclusions: The mutation sites of multidrug-resistant patients in Zunyi are mainly ropB531 and ropBS53 1L mutations, which are prone to co-occurrence; patients with MDR-TB alone are prone to mutations at the KatG3 I5N site, while patients with diabetes and MDR-TB arc more likely to have inhA-15M site mutations.