Distribution and Molecular Characterization of Acinetobacter baumannii International Clone II Lineage in Japan

ABSTRACTMultidrug-resistant (MDR)Acinetobacterspp. have been globally disseminated in association with the successful clonal lineageAcinetobacter baumanniiinternational clone II (IC II). Because the prevalence of MDRAcinetobacterspp. in Japan remains very low, we characterized allAcinetobacterspp. (n= 866) from 76 hospitals between October 2012 and March 2013 to describe the entire molecular epidemiology ofAcinetobacterspp. The most prevalent species wasA. baumannii(n= 645; 74.5%), withA. baumanniiIC II (n= 245) accounting for 28.3% of the total. Meropenem-resistant isolates accounted for 2.0% (n= 17) and carried ISAba1-blaOXA-23-like(n= 10),blaIMP(n= 4), or ISAba1-blaOXA-51-like(n= 3). Multilocus sequence typing of 110 representativeA. baumanniiisolates revealed the considerable prevalence of domestic sequence types (STs).A. baumanniiIC II isolates were divided into the domestic sequence type 469 (ST469) (n= 18) and the globally disseminated STs ST208 (n= 14) and ST219 (n= 4). ST469 isolates were susceptible to more antimicrobial agents, while ST208 and ST219 overproduced the intrinsic AmpC β-lactamase.A. baumanniiIC II and someA. baumanniinon-IC II STs (e.g., ST149 and ST246) were associated with fluoroquinolone resistance. This study revealed that carbapenem-susceptibleA. baumanniiIC II was moderately disseminated in Japan. The low prevalence of acquired carbapenemase genes and presence of domestic STs could contribute to the low prevalence of MDRA. baumannii. A similar epidemiology might have appeared before the global dissemination of MDR epidemic lineages. In addition, fluoroquinolone resistance associated withA. baumanniiIC II may provide insight into the significance ofA. baumanniiepidemic clones.

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Functional Characterization of AbaQ, a Novel Efflux Pump Mediating Quinolone Resistance inAcinetobacter baumannii

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00906-18 ◽

2018 ◽

Vol 62 (9) ◽

Cited By ~ 8

Author(s):

María Pérez-Varela ◽

Jordi Corral ◽

Jesús Aranda ◽

Jordi Barbé

Keyword(s):

Acinetobacter Baumannii ◽

Antimicrobial Agents ◽

Efflux Pump ◽

Functional Characterization ◽

Multidrug Resistant ◽

Quinolone Resistance ◽

Nosocomial Pathogen ◽

Content Type ◽

Mfs Transporter

ABSTRACTAcinetobacter baumanniihas emerged as an important multidrug-resistant nosocomial pathogen. In previous work, we identified a putative MFS transporter, AU097_RS17040, involved in the pathogenicity ofA. baumannii(M. Pérez-Varela, J. Corral, J. A. Vallejo, S. Rumbo-Feal, G. Bou, J. Aranda, and J. Barbé, Infect Immun 85:e00327-17, 2017,https://doi.org/10.1128/IAI.00327-17). In this study, we analyzed the susceptibility to diverse antimicrobial agents ofA. baumanniicells defective in this transporter, referred to as AbaQ. Our results showed that AbaQ is mainly involved in the extrusion of quinolone-type drugs inA. baumannii.

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Characterization of RelA in Acinetobacter baumannii

Journal of Bacteriology ◽

10.1128/jb.00045-20 ◽

2020 ◽

Vol 202 (12) ◽

Cited By ~ 3

Author(s):

María Pérez-Varela ◽

Aimee R. P. Tierney ◽

Ju-Sim Kim ◽

Andrés Vázquez-Torres ◽

Philip Rather

Keyword(s):

Acinetobacter Baumannii ◽

Galleria Mellonella ◽

Multidrug Resistant ◽

Cell Physiology ◽

Content Type ◽

Content Model ◽

Transposon Insertion ◽

Downstream Effectors

ABSTRACT In response to nutrient depletion, the RelA and SpoT proteins generate the signaling molecule (p)ppGpp, which then controls a number of downstream effectors to modulate cell physiology. In Acinetobacter baumannii strain AB5075, a relA ortholog (ABUW_3302) was identified by a transposon insertion that conferred an unusual colony phenotype. An in-frame deletion in relA (ΔrelA) failed to produce detectable levels of ppGpp when amino acid starvation was induced with serine hydroxamate. The ΔrelA mutant was blocked from switching from the virulent opaque colony variant (VIR-O) to the avirulent translucent colony variant (AV-T), but the rate of AV-T to VIR-O switching was unchanged. In addition, the ΔrelA mutation resulted in a pronounced hypermotile phenotype on 0.35% agar plates. This hypermotility was dependent on the activation of a LysR regulator ABUW_1132, which was required for expression of AbaR, a LuxR family quorum-sensing regulator. In the ΔrelA mutant, ABUW_1132 was also required for the increased expression of an operon composed of the ABUW_3766-ABUW_3773 genes required for production of the surfactant-like lipopeptide acinetin 505. Additional phenotypes identified in the ΔrelA mutant included (i) cell elongation at high density, (ii) reduced formation of persister cells tolerant to colistin and rifampin, and (iii) decreased virulence in a Galleria mellonella model. IMPORTANCE Acinetobacter baumannii is a pathogen of worldwide importance. Due to the increasing prevalence of antibiotic resistance, these infections are becoming increasingly difficult to treat. New therapies are required to combat multidrug-resistant isolates. The role of RelA in A. baumannii is largely unknown. This study demonstrates that like in other bacteria, RelA controls a variety of functions, including virulence. Strategies to inhibit the activity of RelA and the resulting production of ppGpp could inhibit virulence and may represent a new therapeutic approach.

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Homeostasis of Glutathione Is Associated with Polyamine-Mediated β-Lactam Susceptibility in Acinetobacter baumannii ATCC 19606

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00692-13 ◽

2013 ◽

Vol 57 (11) ◽

pp. 5457-5461 ◽

Cited By ~ 5

Author(s):

Dong H. Kwon ◽

Saboor Hekmaty ◽

Gomattie Seecoomar

Keyword(s):

Acinetobacter Baumannii ◽

Redox State ◽

Antimicrobial Agents ◽

Multidrug Resistant ◽

Transport Systems ◽

Toxic Substances ◽

Cellular Redox ◽

Content Type ◽

Intracellular Glutathione ◽

Cellular Redox State

ABSTRACTGlutathione is a tripeptide (l-γ-glutamyl–l-cysteinyl–glycine) thiol compound existing in many bacteria and maintains a proper cellular redox state, thus protecting cells against toxic substances such as reactive oxygen species. Polyamines (spermine and spermidine) are low-molecular-weight aliphatic polycations ubiquitously presenting in all living cells and modulate many cellular functions. We previously reported that exogenous polyamines significantly enhanced β-lactam susceptibility of β-lactam-associated multidrug-resistantAcinetobacter baumannii. In this study, three genes differentially associated with the polyamine effects on β-lactam susceptibility were identified by transposon mutagenesis ofA. baumanniiATCC 19606. All three genes encoded components of membrane transport systems. Inactivation of one of the genes encoding a putative glutathione transport ATP-binding protein increased the accumulation of intracellular glutathione (∼150 to ∼200%) and significantly decreased the polyamine effects on β-lactam susceptibility inA. baumanniiATCC 19606. When the cells were grown with polyamines, the levels of intracellular glutathione inA. baumanniiATCC 19606 significantly decreased from ∼0.5 to ∼0.2 nmol, while the levels of extracellular glutathione were correspondingly increased. However, the levels of total glutathione (intra- plus extracellular) were unchanged when the cells were grown with or without polyamines. Overall, these results suggest that exogenous polyamines induce glutathione export, resulting in decreased levels of intracellular glutathione, which may produce an improper cellular redox state that is associated with the polyamine-mediated β-lactam susceptibility ofA. baumannii. This finding may provide a clue for development of new antimicrobial agents and/or novel strategies to treat multidrug-resistantA. baumannii.

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Globally Expanding Carbapenemase Finally Appears in Spain: Nosocomial Outbreak of Acinetobacter baumannii Producing Plasmid-Encoded OXA-23 in Barcelona, Spain

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01486-13 ◽

2013 ◽

Vol 57 (10) ◽

pp. 5155-5157 ◽

Cited By ~ 25

Author(s):

Noraida Mosqueda ◽

Paula Espinal ◽

Clara Cosgaya ◽

Sergio Viota ◽

Virginia Plasensia ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Molecular Characterization ◽

Multidrug Resistant ◽

Sequence Type ◽

Clinical Isolates ◽

Nosocomial Outbreak ◽

Content Type ◽

Hospital Outbreak

ABSTRACTResistance ofAcinetobacter baumanniiclinical isolates to carbapenems is on the rise worldwide mainly in association with the production of OXA-23. Until recently, however, OXA-23 was absent in Spain. In this work, we report the molecular characterization of a hospital outbreak of OXA-23-producingA. baumanniiin Barcelona caused by a multidrug-resistant (MDR) clone belonging to international clone IC-II/sequence type ST85 between October 2010 and May 2011.blaOXA-23was carried in a plasmid of 90 kb and located within the composite transposon Tn2006.

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Molecular and Clinical Characterization of Multidrug-Resistant and Hypervirulent Klebsiella pneumoniae Strains from Liver Abscess in Taiwan

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00174-20 ◽

2020 ◽

Vol 64 (5) ◽

Cited By ~ 6

Author(s):

Yi-Tsung Lin ◽

Yi-Hsiang Cheng ◽

Chien Chuang ◽

Sheng-Hua Chou ◽

Wan-Hsin Liu ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Klebsiella Pneumoniae ◽

Liver Abscess ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Virulence Plasmid ◽

Content Type ◽

Sequence Types

ABSTRACT Hypervirulent Klebsiella pneumoniae strains are the major cause of liver abscesses throughout East Asia, and these strains are usually antibiotic susceptible. Recently, multidrug-resistant and hypervirulent (MDR-HV) K. pneumoniae strains have emerged due to hypervirulent strains acquiring antimicrobial resistance determinants or the transfer of a virulence plasmid into a classic MDR strain. In this study, we characterized the clinical and microbiological properties of K. pneumoniae liver abscess (KPLA) caused by MDR-HV strains in Taiwan. Patients with community onset KPLA were retrospectively identified at Taipei Veterans General Hospital during January 2013 to May 2018. Antimicrobial resistance mechanisms, capsular types, and sequence types were determined. MDR-HV strains and their parental antimicrobial-susceptible strains further underwent whole-genome sequencing (WGS) and in vivo mice lethality tests. Thirteen MDR-HV strains were identified from a total of 218 KPLA episodes. MDR-HV strains resulted in similar outcomes to antimicrobial-susceptible strains. All MDR-HV strains were traditional hypervirulent clones carrying virulence capsular types. The major resistance mechanisms were the overexpression of efflux pumps and/or the acquisition of ESBL or AmpC β-lactamase genes. WGS revealed that two hypervirulent strains had evolved to an MDR phenotype due to mutation in the ramR gene and the acquisition of an SHV-12-bearing plasmid, respectively. Both these MDR-HV strains retained high virulence compared to their parental strains. The spread of MDR-HV K. pneumoniae strains in the community raises significant public concerns, and measures should be taken to prevent the further acquisition of carbapenemase and other resistance genes among these strains in order to avoid the occurrence of untreatable KPLA.

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Complete Genome Sequence of Multidrug-Resistant Acinetobacter baumannii Strain 1656-2, Which Forms Sturdy Biofilm

Journal of Bacteriology ◽

10.1128/jb.06109-11 ◽

2011 ◽

Vol 193 (22) ◽

pp. 6393-6394 ◽

Cited By ~ 37

Author(s):

Jin Yeol Park ◽

Shukho Kim ◽

Sung-Min Kim ◽

Sun Ho Cha ◽

Si-Kyu Lim ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Genome Sequence ◽

Complete Genome Sequence ◽

Biofilm Formation ◽

Complete Genome ◽

Multidrug Resistant ◽

Negative Bacterium ◽

Content Type ◽

Multiple Drugs ◽

Insight Into

Acinetobacter baumanniiis a Gram-negative bacterium causing nosocomial infections worldwide. To gain quick insight into the molecular basis of biofilm formation inA. baumannii, we determined the complete genome sequence ofA. baumanniistrain 1656-2, which forms sturdy biofilm and is resistant to multiple drugs.

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Genomic and Molecular Characterization of Clinical Isolates of Enterobacteriaceae Harboring mcr-1 in Colombia, 2002 to 2016

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00841-17 ◽

2017 ◽

Vol 61 (12) ◽

Cited By ~ 28

Author(s):

Sandra Yamile Saavedra ◽

Lorena Diaz ◽

Magdalena Wiesner ◽

Adriana Correa ◽

Stefany Alejandra Arévalo ◽

...

Keyword(s):

Antimicrobial Agents ◽

Clinical Isolates ◽

Gram Negative ◽

Content Type ◽

E Coli ◽

Carbapenem Resistant ◽

Serovar Typhimurium ◽

Chromosome Conjugation ◽

Sequence Types

ABSTRACT Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Enterobacteriaceae. Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of mcr-1 in Enterobacteriaceae and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all mcr-1-positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of mcr-1 was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored mcr-1, including 8 Escherichia coli, 3 Salmonella enterica serovar Typhimurium, and 1 Klebsiella pneumoniae isolate. E. coli isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups. S. Typhimurium and K. pneumoniae isolates belonged to ST34 and ST307, respectively. The mcr-1 gene was plasmid borne in all isolates but two E. coli isolates which harbored it on the chromosome. Conjugation of mcr-1 was successful in 8 of 10 isolates (8.2 × 10−5 to 2.07 × 10−1 cell per recipient). Plasmid sequences showed that the mcr-1 plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that mcr-1 is circulating in clinical isolates of colistin-resistant Enterobacteriaceae in Colombia and is mainly harbored in transferable plasmids.

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Characterization of Carbapenem-Resistant Acinetobacter baumannii Strains Isolated from Hospitalized Patients in Palestine

International Journal of Microbiology ◽

10.1155/2017/8012104 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 10

Author(s):

Regeen Handal ◽

Lulu Qunibi ◽

Ibrahim Sahouri ◽

Maha Juhari ◽

Rula Dawodi ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Virulence Gene ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Drug Resistant ◽

Single Patient ◽

Carbapenem Resistant ◽

Control And Prevention ◽

Sequence Types

The American Centers for Disease Control and Prevention (CDC) recognizes Acinetobacter baumannii as a source of global outbreaks and epidemics especially due to its increasing resistance to commercially available antibiotics. In this study, 69 single patient multidrug resistant isolates collected from all over Palestine, except Gaza, were studied. All the isolates were resistant to all the β–lactam antibiotics including the carbapenems. Of the 69 isolates, 82.6% were positive for blaOXA-23, 14.5% were positive for blaOXA-24, and 3% were positive for blaOXA-58. None were positive for blaOXA-143 and blaOXA-235. In addition, 5.8% and 0% were positive for blaNDM and blaKPC, respectively. Of the 69 isolates, none were positive for the aminoglycoside aphA6 gene while 93% were positive for the aphA1 gene. The acetyltransferases aacC1 and aacA4 genes tested positive in 22% and 13% of the isolates, respectively. The ompA biofilm-producing virulence gene was detected in all isolates. Finally, Multilocus Sequence Typing (MLST) of 13 isolates revealed that more than one strain of A. baumannii was circulating in Palestinian hospitals as results revealed that 7 isolates were of ST208, 2 isolates ST218, 1 isolate ST231, 1 isolate ST348, and 2 new Sequence Types. The detection of these drug resistant pathogens is a reminder of the importance of active surveillance for resistant bacteria in order to prevent their spread in hospital settings.

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First Whole-Genome Sequences of Two Multidrug-Resistant Acinetobacter baumannii Strains Isolated from a Moroccan Hospital Floor

Genome Announcements ◽

10.1128/genomea.00298-17 ◽

2017 ◽

Vol 5 (18) ◽

Cited By ~ 2

Author(s):

Tarek Alouane ◽

Jean Uwingabiye ◽

Abdelhay Lemnouer ◽

Lamiaa Lahlou ◽

Meriem Laamarti ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Multidrug Resistant ◽

Whole Genome Shotgun ◽

Whole Genome ◽

Genome Sequences ◽

Content Type

ABSTRACT This report describes the whole-genome shotgun sequences of two multidrug-resistant Acinetobacter baumannii strains, ABE8_07 and ABE12_M, isolated from a Moroccan hospital floor. These two genome sequences will initiate the study and characterization of the Acinetobacter baumannii genome in Morocco.

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Changing Antimicrobial Resistance Profiles among Neisseria gonorrhoeae Isolates in Italy, 2003 to 2012

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00103-14 ◽

2014 ◽

Vol 58 (10) ◽

pp. 5871-5876 ◽

Cited By ~ 13

Author(s):

Anna Carannante ◽

Giovanna Renna ◽

Ivano Dal Conte ◽

Valeria Ghisetti ◽

Alberto Matteelli ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Neisseria Gonorrhoeae ◽

Antimicrobial Agents ◽

Multidrug Resistant ◽

Resistance Rate ◽

Health Concern ◽

Content Type ◽

Resistance Patterns ◽

Sex With Men ◽

Sequence Types

ABSTRACTThe emergence ofNeisseria gonorrhoeaeisolates displaying resistance to antimicrobial agents is a major public health concern and a serious issue related to the occurrence of further untreatable gonorrhea infections. A retrospective analysis on 1,430N. gonorrhoeaeisolates, collected from 2003 through 2012, for antimicrobial susceptibility by Etest and molecular characterization byNeisseria gonorrhoeaemultiantigen sequence typing (NG-MAST) was carried out in Italy. Azithromycin-resistant gonococci decreased from 14% in 2007 to 2.2% in 2012. Similarly, isolates with high MICs to cefixime (>0.125 mg/liter) decreased from 11% in 2008 to 3.3% in 2012. The ciprofloxacin resistance rate remains quite stable, following an increasing trend up to 64% in 2012. The percentage of penicillinase-producingN. gonorrhoeae(PPNG) significantly declined from 77% in 2003 to 7% in 2012. A total of 81 multidrug-resistant (MDR) gonococci were identified, showing 11 different antimicrobial resistance patterns. These were isolated from men who have sex with men (MSM) and from heterosexual patients. Two sequence types (STs), ST661 and ST1407, were the most common. Genogroup 1407, which included cefixime-, ciprofloxacin-, and azithromycin-resistant isolates, was found. In conclusion, a change in the antimicrobial resistance profiles among gonococci was identified in Italy together with a percentage of MDR isolates.

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