Mutations at Novel Sites in pmrA/B and lpxA/D Genes and Absence of Reduced Fitness in Colistin-Resistant Acinetobacter baumannii from a Tertiary Care Hospital, India

Sharma, Swati; Banerjee, Tuhina; Yadav, Ghanshyam; Palandurkar, Kamlesh

doi:10.1089/mdr.2020.0023

Cited by 7 publications

(9 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All the 14 isolates of K. pneumoniae from neonatal sepsis were resistant to all the tested antibiotics including carbapenems and colistin. Among the isolates from patients in other parts of the hospital, 17 of the 18 isolates from 18 cases of sepsis (3) and pneumonia (15) in the ICU were also resistant to all the tested antibiotics including carbapenems and colistin. Additionally, the remaining 7 isolates from other wards were susceptible to carbapenems and colistin with the exception of 1 isolate from MSW which was resistant to carbapenem.…”

Section: Antimicrobial Susceptibility Profile Of the Isolatesmentioning

confidence: 99%

Extensive outbreak of colistin resistant, carbapenemase (blaOXA-48, blaNDM) producing Klebsiella pneumoniae in a large tertiary care hospital, India

Sharma

Banerjee

Kumar

et al. 2022

Antimicrob Resist Infect Control

Self Cite

View full text Add to dashboard Cite

Background Extensive drug resistance in Klebsiella pneumoniae (K. pneumoniae) causing major outbreaks in large hospitals is an emerging challenge. We describe a near fatal outbreak of colistin resistant, carbapenem resistant K. pneumoniae (CRKp) producing metallo beta-lactamases (blaNDM) and blaOXA-48 in the neonatal intensive care unit (NICU) at the background of a larger outbreak involving multiple parts of the hospital and the challenges in its containment. Methods Following identification of an outbreak due to colistin resistant CRKp between April to June 2017 in the NICU, a thorough surveillance of similar cases and the hospital environment was performed to trace the source. All the isolated K. pneumoniae were tested for susceptibility to standard antibiotics by disc diffusion and microbroth dilution methods. Molecular detection of extended spectrum beta lactamases (ESBLs) and carbapenemases (classes A, B, D) genes was done. Enterobacterial repetitive intergenic consensus (ERIC) PCR and multi-locus sequence typing (MLST) was done to determine the genetic relatedness of the isolates. Characteristics of different sequence types were statistically compared (Student’s t-test). Results A total of 45 K. pneumoniae isolates were studied from NICU (14 cases of neonatal sepsis), ICU (18 cases), other wards (7 cases) along with 6 isolates from hospital environment and human colonizers. The primary case was identified in the ICU. All the K. pneumoniae from NICU and 94.4% from the ICU were colistin resistant CRKp. Majority (59.37% and 56.25%) harbored blaSHV/blaCTXM and blaOXA-48 genes, respectively. Two distinct sequence types ST5235 and ST5313 were noted with colistin resistance, distribution within the NICU and mortality as significant attributes of ST5235 (p < 0.05). The outbreak was contained with strengthening of the infection control practices and unintended short duration closure of the hospital. Conclusion Large hospital outbreaks with considerable mortality can be caused by non-dominant clones of colistin resistant CRKp harboring blaOXA-48 and blaNDM carbapenemases in endemic regions. The exact global impact of these sequence types should be further studied to prevent future fatal outbreaks.

show abstract

Section: Antimicrobial Susceptibility Profile Of the Isolatesmentioning

confidence: 99%

Extensive outbreak of colistin resistant, carbapenemase (blaOXA-48, blaNDM) producing Klebsiella pneumoniae in a large tertiary care hospital, India

Sharma

Banerjee

Kumar

et al. 2022

Antimicrob Resist Infect Control

Self Cite

View full text Add to dashboard Cite

show abstract

“…None of the isolates showed the presence of mcr genes. Among the 25 colistin resistant A. baumannii isolates, 9 had a mutation in the pmrA/B and lpxA/D genes as the major mechanism of resistance, as previously characterized ( 3 ). The resistance mechanisms in the other 16 resistant isolates have not been investigated.…”

Section: Resultsmentioning

confidence: 74%

“… P. aeruginosa ATCC 27853 and A. baumannii ATCC 19606 were used as standard controls. All of the colistin resistant isolates were tested for the presence of mcr-1 , mcr-2 , mcr-3 , mcr-4 , and mcr-5 genes ( 3 ).…”

Section: Methodsmentioning

confidence: 99%

“…In this context, the colistin broth disk elution (CBDE) method, which is easier to perform, has been approved for many multidrug resistant organisms (e.g., Enterobacterales, Pseudomonas aeruginosa ) but not for A. baumannii ( 2 ). The 2,000-bed tertiary care hospital that participated in this study has already been challenged by outbreaks and the endemicity of CRAB in its intensive care units against a background of considerable empirical colistin use ( 3 , 4 ). During the conduct of the study, analyses of colistin susceptibility against A. baumannii were not performed routinely by the diagnostic laboratory.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation Report of the Colistin Broth Disk Elution Method with Acinetobacter baumannii Isolates from a Low-Resource Setting

et al. 2022

View full text Add to dashboard Cite

The relatively cumbersome broth microdilution (BMD) method for routine colistin susceptibility testing has not been adopted, especially in low-resource settings, often leading to the underreporting of colistin susceptibility and the promotion of the empirical use of colistin. In this regard, the much-preferred colistin broth disk elution (CBDE) method has not yet been approved for A. baumannii .

show abstract

“…We have also studied sustained outbreak of CRAB wherein, it was shown that intense carbapenem use within the ICU facilitated the persistence of the CRAB isolates in the hospital environment causing repeated outbreaks (Sharma et al, 2021a). We then studied colistin resistance in CRAB isolates wherein all the resistant isolates were reported in patients with prior carbapenem therapy (Sharma et al, 2021b). To meet the heavy empirical carbapenem use we also tried to restrict the empirical therapy by detecting biomass through a low-cost hand-held microscope (Foldscope) (Sharma et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Susceptibility profile of blaOXA-23 and metallo-β-lactamases co-harbouring isolates of carbapenem resistant Acinetobacter baumannii (CRAB) against standard drugs and combinations

Sharma

Banerjee²,

Yadav³

et al. 2023

Front. Cell. Infect. Microbiol.

Self Cite

View full text Add to dashboard Cite

BackgroundThe rapid emergence of carbapenem resistant Acinetobacter baumannii (CRAB) has resulted in an alarming situation worldwide. Realizing the dearth of literature on susceptibility of CRAB in genetic context in the developing region, this study was performed to determine the susceptibility profile against standard drugs/combinations and the association of in-vitro drug synergy with the prevalent molecular determinants.Methods and findingsA total of 356 clinical isolates of A. baumannii were studied. Confirmation of the isolates was done by amplifying recA and ITS region genes. Susceptibility against standard drugs was tested by Kirby Bauer disc diffusion. Minimum inhibitory concentration (MIC), MIC50 and MIC90 values against imipenem, meropenem, doripenem, ampicillin/sulbactam, minocycline, amikacin, polymyxin B, colistin and tigecycline was tested as per guidelines. Genes encoding enzymes classes A (blaGES, blaIMI/NMC-A, blaSME, blaKPC), B (blaIMP, blaVIM, blaNDM) and D (blaOXA-51,blaOXA-23 and blaOXA-58) were detected by multiplex polymerase chain reaction. Synergy against meropenem-sulbactam and meropenem-colistin combinations was done by checkerboard MIC method. Correlation of drug synergy and carbapenemase encoding genes was statistically analyzed.ResultsOf the total, resistance above 90% was noted against gentamicin, ciprofloxacin, levofloxacin, ceftazidime, cefepime, ceftriaxone, cotrimoxazole and piperacillin/tazobactam. By MIC, resistance rates from highest to lowest was seen against imipenem 89.04% (n=317), amikacin 80.33% (n=286), meropenem 79.49% (n=283), doripenem 77.80% (n=277), ampicillin/sulbactam 71.62% (n=255), tigecycline 55.61% (n=198), minocycline 14.04% (n=50), polymyxin B 10.11% (n=36), and colistin 2.52% (n=9). CRAB was 317 (89.04%), 81.46% (n=290) were multidrug resistant and 13.48% (n=48) were extensively drug resistant. All the CRAB isolates harboured blaOXA-51 gene (100%) and 94% (n=298) blaOXA-23 gene. The blaIMP gene was most prevalent 70.03% (n=222) followed by blaNDM, 59.62% (n=189). Majority (87.69%, 278) were co-producers of classes D and B carbapenemases, blaOXA-23 with blaIMP and blaNDM being the commonest. Synergy with meropenem-sulbactam and meropenem-colistin was 47% and 57% respectively. Reduced synergy (p= <0.0001) was noted for those harbouring blaOXA-51+blaOXA-23with blaNDM gene alone or co-producers.ConclusionPresence of blaNDM gene was a significant cause of synergy loss in meropenem-sulbactam and meropenem-colistin. In blaNDM endemic regions, tigecycline, minocycline and polymyxins could be viable options against CRAB isolates with more than one carbapenemase encoding genes.

show abstract

Mutations at Novel Sites in pmrA/B and lpxA/D Genes and Absence of Reduced Fitness in Colistin-Resistant Acinetobacter baumannii from a Tertiary Care Hospital, India

Cited by 7 publications

References 37 publications

Extensive outbreak of colistin resistant, carbapenemase (blaOXA-48, blaNDM) producing Klebsiella pneumoniae in a large tertiary care hospital, India

Extensive outbreak of colistin resistant, carbapenemase (blaOXA-48, blaNDM) producing Klebsiella pneumoniae in a large tertiary care hospital, India

Evaluation Report of the Colistin Broth Disk Elution Method with Acinetobacter baumannii Isolates from a Low-Resource Setting

Susceptibility profile of blaOXA-23 and metallo-β-lactamases co-harbouring isolates of carbapenem resistant Acinetobacter baumannii (CRAB) against standard drugs and combinations

Contact Info

Product

Resources

About