Dataset Information

Seasonal Occurrence and Carbapenem Susceptibility of Bovine Acinetobacter baumannii in Germany.

ABSTRACT: Acinetobacter baumannii is one of the leading causes of nosocomial infections in humans. To investigate its prevalence, distribution of sequence types (STs), and antimicrobial resistance in cattle, we sampled 422 cattle, including 280 dairy cows, 59 beef cattle, and 83 calves over a 14-month period. Metadata, such as the previous use of antimicrobial agents and feeding, were collected to identify putative determining factors. Bacterial isolates were identified via MALDI-TOF/MS and PCR, antimicrobial susceptibility was evaluated via VITEK2 and antibiotic gradient tests, resistance genes were identified by PCR. Overall, 15.6% of the cattle harbored A. baumannii, predominantly in the nose (60.3% of the A. baumannii isolates). It was more frequent in dairy cows (21.1%) than in beef cattle (6.8%) and calves (2.4%). A seasonal occurrence was shown with a peak between May and August. The rate of occurrence of A. baumannii was correlated with a history of use of 3rd generation cephalosporins in the last 6 months prior to sampling Multilocus sequence typing (Pasteur scheme) revealed 83 STs among 126 unique isolates. Nine of the bovine STs have previously been implicated in human infections. Besides known intrinsic resistance of the species, the isolates did not show additional resistance to the antimicrobial substances tested, including carbapenems. Our data suggest that cattle are not a reservoir for nosocomial A. baumannii but carry a highly diverse population of this species. Nevertheless, some STs seem to be able to colonize both cattle and humans.

SUBMITTER: Klotz P

PROVIDER: S-EPMC6395434 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Seasonal Occurrence and Carbapenem Susceptibility of Bovine <i>Acinetobacter baumannii</i> in Germany.

Klotz Peter P Higgins Paul G PG Schaubmar Andreas R AR Failing Klaus K Leidner Ursula U Seifert Harald H Scheufen Sandra S Semmler Torsten T Ewers Christa C

Frontiers in microbiology 20190222

<i>Acinetobacter baumannii</i> is one of the leading causes of nosocomial infections in humans. To investigate its prevalence, distribution of sequence types (STs), and antimicrobial resistance in cattle, we sampled 422 cattle, including 280 dairy cows, 59 beef cattle, and 83 calves over a 14-month period. Metadata, such as the previous use of antimicrobial agents and feeding, were collected to identify putative determining factors. Bacterial isolates were identified via MALDI-TOF/MS and PCR, an ...[more]

PMID: 30853949

Similar Datasets

Project description:BackgroundWith an increase in the use of colistin methansulfonate (CMS) to treat carbapenem-resistant Acinetobacter baumannii infections, colistin resistance is emerging.MethodsPatients with infection or colonization due to colistin-resistant A. baumannii were identified at a hospital system in Pennsylvania. Clinical data were collected from electronic medical records. Susceptibility testing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) were performed. To investigate the mechanism of colistin resistance, lipid A was subjected to matrix-assisted laser desorption/ionization mass spectrometry.ResultsTwenty patients with colistin-resistant A. baumannii were identified. Ventilator-associated pneumonia was the most common type of infection. Nineteen patients had received intravenous and/or inhaled CMS for treatment of carbapenem-resistant, colistin-susceptible A. baumannii infection prior to identification of colistin-resistant isolates. The 30-day all-cause mortality rate was 30%. The treatment regimen for colistin-resistant A. baumannii infection associated with the lowest mortality rate was a combination of CMS, a carbapenem, and ampicillin-sulbactam. The colistin-susceptible and -resistant isolates from the same patients were highly related by PFGE, but isolates from different patients were not, suggesting evolution of resistance during CMS therapy. By MLST, all isolates belonged to the international clone II, the lineage that is epidemic worldwide. Phosphoethanolamine modification of lipid A was present in all colistin-resistant A. baumannii isolates.ConclusionsColistin-resistant A. baumannii occurred almost exclusively among patients who had received CMS for treatment of carbapenem-resistant, colistin-susceptible A. baumannii infection. Lipid A modification by the addition of phosphoethanolamine accounted for colistin resistance. Susceptibility testing for colistin should be considered for A. baumannii identified from CMS-experienced patients.

Project description:Purpose:Acinetobacter baumannii is an important pathogen in the nosocomial infections worldwide. Combining with carbapenemases, efflux pumps and outer membrane proteins (OMPs) have been thought to affect the development of carbapenem resistance in A. baumannii. This study aimed to investigate the contributions of different efflux pumps and OMPs in developing carbapenem resistance in a clinical isolate of A. baumannii and reveal the possible mechanism of overproduction of main efflux pumps. Patients and methods:In this study, an imipenem-susceptible clinical isolate was identified as A. baumannii and named SZE. Several common carbapenemases were detected by polymerase chain reaction (PCR). Imipenem-selected mutants were selected from SZE by serial subcultivations on Mueller-Hinton agar, and the minimum inhibitory concentration (MIC) was detected. Gene expressions of four families of efflux pumps, five OMPs, and blaOXA-51 were determined by reverse transcription quantitative PCR, and comparisons were made between SZE strain and the imipenem-selected mutants. The adeRS system in SZE and its mutant was sequenced and aligned. Results:Under consecutive imipenem-selected stress, the MIC to imipenem increased gradually from 0.125 ?g/mL to 8 ?g/mL. The effect of resistance inducement was almost neutralized when treated with an efflux pump inhibitor. The expression of efflux pumps, adeB, adeG, and adeJ, was increased by 6.9-, 4.0-, and 2.1-fold in mutants, respectively, compared to SZE. A single mutation (G to A) at position 58 was detected in the regulatory adeRS system and possibly upregulated the adeB expression, and then affected the carbapenem resistance in A. baumannii strains. Conclusion:In conclusion, under consecutive imipenem-selected stress in vitro, A. baumannii strain evolved the ability to reduce susceptibility to a variety of antimicrobials by overproduction of efflux pumps. Especially, the resistance-nodulation-cell division super family and a nucleotide mutant in adeRS regulating system caused the overexpression of adeABC.

Dataset Information

Seasonal Occurrence and Carbapenem Susceptibility of Bovine Acinetobacter baumannii in Germany.

Publications

Seasonal Occurrence and Carbapenem Susceptibility of Bovine <i>Acinetobacter baumannii</i> in Germany.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets