scholarly journals Elizabethkingia Infections in Humans: From Genomics to Clinics

2019 ◽  
Vol 7 (9) ◽  
pp. 295 ◽  
Author(s):  
Jiun-Nong Lin ◽  
Chung-Hsu Lai ◽  
Chih-Hui Yang ◽  
Yi-Han Huang
Keyword(s):  
Target Gene ◽  
Gene Mutations ◽  
Housekeeping Gene ◽  
Molecular Techniques ◽  
Fluoroquinolone Resistance ◽  
Emerging Pathogens ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Elizabethkingia Meningoseptica ◽  
Life Threatening

The genus Elizabethkingia has recently emerged as a cause of life-threatening infections in humans, particularly in immunocompromised patients. Several new species in the genus Elizabethkingia have been proposed in the last decade. Numerous studies have indicated that Elizabethkingia anophelis, rather than Elizabethkingia meningoseptica, is the most prevalent pathogen in this genus. Matrix-assisted laser desorption/ionization–time of flight mass spectrometry systems with an extended spectrum database could reliably identify E. anophelis and E. meningoseptica, but they are unable to distinguish the remaining species. Precise species identification relies on molecular techniques, such as housekeeping gene sequencing and whole-genome sequencing. These microorganisms are usually susceptible to minocycline but resistant to most β-lactams, β-lactam/β-lactam inhibitors, carbapenems, and aminoglycosides. They often exhibit variable susceptibility to piperacillin, piperacillin-tazobactam, fluoroquinolones, and trimethoprim-sulfamethoxazole. Accordingly, treatment should be guided by antimicrobial susceptibility testing. Target gene mutations are markedly associated with fluoroquinolone resistance. Knowledge on the genomic characteristics provides valuable insights into in these emerging pathogens.

scholarly journals Role of Active Efflux in Association with Target Gene Mutations in Fluoroquinolone Resistance in Clinical Isolates of Vibrio cholerae

2002 ◽  
Vol 46 (8) ◽  
pp. 2676-2678 ◽  
Author(s):  
Somesh Baranwal ◽  
Keya Dey ◽  
T. Ramamurthy ◽  
G. Balakrish Nair ◽  
Manikuntala Kundu
Keyword(s):  
Vibrio Cholerae ◽  
Target Gene ◽  
Target Genes ◽  
Gene Mutations ◽  
Proton Motive Force ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Active Efflux

ABSTRACT Quinolones are among the drugs of choice in the management of cholera caused by Vibrio cholerae. In this study, we demonstrate that, in addition to mutations detected in the target genes gyrA and parC, proton motive force-dependent efflux is involved in quinolone resistance in clinical isolates of V. cholerae.

scholarly journals Comparison of Clinical Manifestations, Antimicrobial Susceptibility Patterns, and Mutations of Fluoroquinolone Target Genes between Elizabethkingia meningoseptica and Elizabethkingia anophelis Isolated in Taiwan

2018 ◽  
Vol 7 (12) ◽  
pp. 538 ◽  
Author(s):  
Jiun-Nong Lin ◽  
Chung-Hsu Lai ◽  
Chih-Hui Yang ◽  
Yi-Han Huang
Keyword(s):  
Ribosomal Rna ◽  
Target Gene ◽  
Target Genes ◽  
Clinical Manifestations ◽  
Gene Mutations ◽  
Clinical Microbiology Laboratory ◽  
Elizabethkingia Meningoseptica ◽  
Major Pathogens ◽  
Susceptibility Patterns ◽  
Multiple Antibiotics

Elizabethkingia meningoseptica and Elizabethkingia anophelis are two major pathogens in the genus Elizabethkingia. Studies have revealed that Elizabethkingia anophelis is frequently misidentified as E. meningoseptica. Therefore, our aim was to explore the clinical and molecular differences between these two species. The database of a clinical microbiology laboratory in a university-affiliated hospital of Taiwan was searched to identify patients with Elizabethkingia infections between January 2005 and June 2018. Species were reidentified using 16S ribosomal RNA gene sequencing. Twenty E. meningoseptica and 72 E. anophelis samples were collected from consecutive patients. E. meningoseptica was significantly more frequently isolated from the cerebrospinal fluid than was E. anophelis. The most susceptible antibiotic for all Elizabethkingia isolates was minocycline (91.3%), followed by levofloxacin (52.2%), tigecycline (23.9%), and piperacillin tazobactam (23.9%). Compared with E. anophelis, E. meningoseptica was significantly less susceptible to piperacillin tazobactam, minocycline, and levofloxacin. Regarding nonsynonymous substitutions in the quinolone-resistance determining regions of DNA gyrase, six sites were recognized in E. meningoseptica and one site was recognized in E. anophelis. E. meningoseptica had a significantly higher rate of fluoroquinolone target gene mutations than did E. anophelis. Because of less susceptibility to multiple antibiotics than E. anophelis, empirical antimicrobial therapy of E. meningoseptica should be more rigorous.

scholarly journals Ineffectiveness of Topoisomerase Mutations in Mediating Clinically Significant Fluoroquinolone Resistance inEscherichia coli in the Absence of the AcrAB Efflux Pump

2000 ◽  
Vol 44 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Margret Oethinger ◽  
Winfried V. Kern ◽  
Angelika S. Jellen-Ritter ◽  
Laura M. McMurry ◽  
Stuart B. Levy
Keyword(s):  
Target Gene ◽  
Efflux Pump ◽  
Regulatory Gene ◽  
Gene Mutations ◽  
Fluoroquinolone Resistance ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Acrab Efflux Pump ◽  
Clinically Significant ◽  
K 12

ABSTRACT Fluoroquinolone-resistant mutants, selected from a wild-typeEscherichia coli K-12 strain and its Mar mutant by exposure to increasing levels of ofloxacin on solid medium, were analyzed by Northern (RNA) blot analysis, sequencing, and radiolabelled ciprofloxacin accumulation studies. Mutations in the target genegyrA (DNA gyrase), the regulatory gene marR, and additional, as yet unidentified genes (genes that probably affect efflux mediated by the multidrug efflux pump AcrAB) all contributed to fluoroquinolone resistance. Inactivation of the acrAB locus made all strains, including those with target gene mutations, hypersusceptible to fluoroquinolones and certain other unrelated drugs. These studies indicate that, in the absence of the AcrAB pump, gyrase mutations fail to produce clinically relevant levels of fluoroquinolone resistance.

scholarly journals Globicatella sanguinis Osteomyelitis and Bacteremia: Review of an Emerging Human Pathogen with an Expanding Spectrum of Disease

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Andy O. Miller ◽  
Seanne P. Buckwalter ◽  
Michael W. Henry ◽  
Fann Wu ◽  
Katherine F. Maloney ◽  
...  
Keyword(s):  
Molecular Techniques ◽  
Obese Women ◽  
Ionization Time ◽  
Minimum Inhibitory Concentrations ◽  
Flight Mass Spectrometry ◽  
Mucosal Surfaces ◽  
Hip Infection ◽  
Phenotypic Methods ◽  
Viridans Group Streptococci ◽  
Orthopedic Infection

Abstract Background Globicatella sanguinis is an uncommon pathogen that may be misdiagnosed as viridans group streptococci. We review the literature of Globicatella and report 2 clinical cases in which catalase-negative Gram-positive cocci resembling viridans group streptococci with elevated minimum inhibitory concentrations (MICs) to ceftriaxone were inconsistently identified phenotypically, with further molecular characterization and ultimate identification of G sanguinis. Methods Two clinical strains (from 2 obese women; 1 with a prosthetic hip infection and the other with bacteremia) were analyzed with standard identification methods, followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, 16S recombinant ribonucleic acid (rRNA), and sodA polymerase chain reaction (PCR). The existing medical literature on Globicatella also was reviewed. Results Standard phenotypic methods failed to consistently identify the isolates. 16S PCR yielded sequences that confirmed Globicatella species. sodA sequencing provided species-level identification of G sanguinis. The review of literature reveals G sanguinis as an increasingly reported cause of infections of the urine, meninges, and blood. To our knowledge, this is the first reported case of an orthopedic infection caused by Globicatella sanguinis. A review of the 37 known cases of G sanguinis infection revealed that 83% of patients are female, and 89% are at the extremes of age (<5 or >65 years). Conclusions Globicatella sanguinis, an uncommon pathogen with elevated minimum inhibitory concentrations to third-generation cephalosporins, is difficult to identify by phenotypic methods and typically causes infections in females at the extremes of age. It may colonize skin or mucosal surfaces. Advanced molecular techniques utilizing 16S rRNA with sodA PCR accurately identify G sanguinis.

scholarly journals The incidence and antibiotic resistance of Salmonella species isolated from cloacae of captive veiled chameleons

2015 ◽  
Vol 84 (3) ◽  
pp. 209-213 ◽  
Author(s):  
Silvia Barazorda Romero ◽  
Zdeněk Knotek ◽  
Alois Čížek ◽  
Martina Masaříková ◽  
Petra Myšková
Keyword(s):  
Antibiotic Resistance ◽  
Intestinal Flora ◽  
Health Concern ◽  
Laser Desorption Ionization ◽  
Public Health Concern ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
In Captivity ◽  
Life Threatening ◽  
Potential Public Health

Salmonellacan be present in the intestinal flora of captive reptiles without clinical disease or it can cause life threatening morbidity. The presence of certain species ofSalmonellain reptiles is consistent with them being the source of contamination in some cases of human disease. Thus,Salmonellapositive animals can be a potential public health concern even more when strains acquire resistance to antibiotics. The nature and extent ofSalmonellaharboured by different species of reptiles commonly kept in captivity are not known. The aims of this study were to analyse the incidence ofSalmonellaspecies in cloacae as an indicator of the intestinal flora in a cohort of healthy captive bred female veiled chameleons. A cloacal sample was taken from each of fifteen healthy captive bred, adult female veiled chameleons that were housed at a teaching and research clinic.Salmonellaisolates were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry and positive cases were serotyped by slide agglutination test.Salmonellaorganisms were detected in 12 chameleons. Eighty percent of chameleons harboured 1 of 4 subspecies and serovars ofSalmonella. All strains belonged to the speciesenterica, predominantly subspeciesenterica(91.7 %) and were distributed among 4 different serovars:S.Ago (58.3 %),S.Blijdorp (16.7 %),S.Tennessee (16.7 %) andS.IV 45:g,z51:- (8.3 %). Antibiotic resistance to streptomycin was detected in one of 12Salmonellastrains:S.IV 45:g,z51:-. Our study extended the list ofSalmonellafound in healthy captive animals and included serovarsS.Tennessee andS.IV 45:g,z51:- that have been associated with morbidity in humans.

scholarly journals Non-Target Gene Mutations in the Development of Fluoroquinolone Resistance in Escherichia coli

2000 ◽  
Vol 44 (4) ◽  
pp. 814-820 ◽  
Author(s):  
W. V. Kern ◽  
M. Oethinger ◽  
A. S. Jellen-Ritter ◽  
S. B. Levy
Keyword(s):  
Escherichia Coli ◽  
Target Gene ◽  
Constitutive Expression ◽  
Gene Mutations ◽  
Fluoroquinolone Resistance ◽  
Second Step ◽  
Solvent Tolerance ◽  
E Coli ◽  
K 12

ABSTRACT Mutations in loci other than genes for the target topoisomerases of fluoroquinolones, gyrA and parC, may play a role in the development of fluoroquinolone resistance inEscherichia coli. A series of mutants with increasing resistance to ofloxacin was obtained from an E. coli K-12 strain and five clinical isolates. First-step mutants acquired agyrA mutation. Second-step mutants reproducibly acquired a phenotype of multiple antibiotic resistance (Mar) and organic solvent tolerance and showed enhanced fluoroquinolone efflux. None of the second-step mutants showed additional topoisomerase mutations. All second-step mutants showed constitutive expression of marAand/or overexpressed soxS. In some third-step mutants, fluoroquinolone efflux was further enhanced compared to that for second-step mutants, even when the mutant had acquired additional topoisomerase mutations. Attempts to circumvent the second-step Mar mutation by induction of the mar locus with sodium salicylate and thus to select for pure topoisomerase mutants at the second step were not successful. At least in vitro, non-target gene mutations accumulate in second- and third-step mutants upon exposure to a fluoroquinolone and typically include, but do not appear to be limited to, mutations in the mar or soxregulons with consequent increased drug efflux.

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