Molecular Epidemiology of Clinical Carbapenem-Resistant Acinetobacter baumannii-calcoaceticus complex Isolates in Tertiary Care Hospitals in Java and Sulawesi Islands, Indonesia

Carbapenem-resistant Acinetobacter baumannii (A. baumannii)-calcoaceticus complex (CRAb-cc) is an important pathogen causing nosocomial infections worldwide; however, molecular epidemiology of the A. baumannii-calcoaceticus complex in Indonesian hospitals is scarce. This study aimed to determine the clonal relatedness of CRAb-cc in two tertiary care hospitals in Malang and Manado in Indonesia. The CRAb-cc isolates from routine clinical cultures in two tertiary care hospitals in Malang and Manado were identified using the Vitek2^® system (bioMérieux, Lyon, France). Multi-locus variable-number tandem-repeat analysis (MLVA) typing, multi-locus sequence typing (MLST), clonal complex (CC), and phylogenetic tree analysis were conducted for a subset of isolates. Seventy-three CRAb-cc isolates were collected. The CRAb-cc isolates were frequently found among lower-respiratory-tract specimens. We detected the MLVA type (MT) 1, MT3, and MT4 CRAB-cc isolates belonging to the sequence type (ST) 642, and CC1 was the predominant clone in this study. In conclusion, we identified the clonal relatedness of A. baumannii-calcoaceticus complex isolates in two tertiary care hospitals in Malang and Manado in Indonesia. Further study is required to investigate the clinical importance and distribution of ST642 in Indonesian hospitals for developing prevention and control measures.

Distribution of Carbapenemase Genes among Carbapenem-Non-Susceptible Acinetobacter baumanii Blood Isolates in Indonesia: A Multicenter Study

Carbapenem non-susceptible Acinetobacter baumannii (CNSAB) is an important pathogen that causes nosocomial bacteremia among critically ill patients worldwide. The magnitude of antibiotic resistance of A. baumanii in Indonesia is expected to be significant; however, the data available are limited. The aim of this study was to analyze the genetic profiles of CNSAB isolates from patients with bacteremia in Indonesia. CNSAB isolates from blood cultures of bacteremia patients in 12 hospitals in Indonesia were included. The blood cultures were conducted using the BacT/Alert or BACTEC automated system. The CNSAB were identified with either Vitek 2 system or Phoenix platform followed by a confirmation test using a multiplex polymerase chain reaction (PCR) assay, targeting the specific gyrB gene. The carbapenemase genes were detected by multiplex PCR. In total, 110 CNSAB isolates were collected and were mostly resistant to nearly all antibiotic classes. The majority of CNSAB isolates were susceptible to tigecycline and trimethoprim-sulfamethoxazole (TMP-SMX), 45.5% and 38.2%, respectively. The bla_OXA-51-like gene was identified in all CNSAB isolates. Out of the total, 83.6% of CNSAB isolates had bla_OXA-23-like gene, 37.3% bla_OXA-24-like gene, 4.5% bla_NDM-1 gene, 0.9% bla_IMP-1 gene, and 0.9% bla_VIM gene. No bla_OXA-48-like gene was identified. The bla_OXA-23-like gene was the predominant gene in all except two hospitals. The presence of the bla_OXA-24-like gene was associated with resistance to tigecycline, amikacin, TMP-SMX and cefoperazone-sulbactam, while bla_OXA-23-like gene was associated with resistance to TMP-SMX and cefoperazone-sulbactam. In conclusion, the bla_OXA-23-like gene was the predominant gene among CNSAB isolates throughout Indonesia. A continuous national surveillance system needs to be established to further monitor the genetic profiles of CNSAB in Indonesia.