scholarly journals Lineage, Antimicrobial Resistance and Virulence of Citrobacter spp

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 195
Author(s):  
Liyun Liu ◽  
Liyun Qin ◽  
Shuai Hao ◽  
Ruiting Lan ◽  
Baohong Xu ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Susceptibility Testing ◽  
Severe Disease ◽  
Multidrug Resistant ◽  
Human Pathogens ◽  
Lineage Iv ◽  
Sequence Types ◽  
Virulence Properties ◽  
New Alleles

Citrobacter spp. are opportunistic human pathogens which can cause nosocomial infections, sporadic infections and outbreaks. In order to determine the genetic diversity, in vitro virulence properties and antimicrobial resistance profiles of Citrobacter spp., 128 Citrobacter isolates obtained from human diarrheal patients, foods and environment were assessed by multilocus sequence typing (MLST), antimicrobial susceptibility testing and adhesion and cytotoxicity testing to HEp-2 cells. The 128 Citrobacter isolates were typed into 123 sequence types (STs) of which 101 were novel STs, and these STs were divided into five lineages. Lineages I and II contained C. freundii isolates; Lineage III contained all C. braakii isolates, while Lineage IV and V contained C. youngae isolates. Lineages II and V contained more adhesive and cytotoxic isolates than Lineages I, III, and IV. Fifty-one of the 128 isolates were found to be multidrug-resistant (MDR, ≥3) and mainly distributed in Lineages I, II, and III. The prevalence of quinolone resistance varied with Lineage III (C. braakii) having the highest proportion of resistant isolates (52.6%), followed by Lineage I (C. freundii) with 23.7%. Seven qnrB variants, including two new alleles (qnrB93 and qnrB94) were found with Lineage I being the main reservoir. In summary, highly cytotoxic MDR isolates from diarrheal patients may increase the risk of severe disease.

scholarly journals Enterobacteriaceae isolates carrying the New Delhi metallo-β-lactamase gene in Yemen

2014 ◽  
Vol 63 (10) ◽  
pp. 1316-1323 ◽  
Author(s):  
Alima Gharout-Sait ◽  
Samer-Ahmed Alsharapy ◽  
Lucien Brasme ◽  
Abdelaziz Touati ◽  
Rachida Kermas ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Susceptibility Testing ◽  
Enterobacter Cloacae ◽  
New Delhi ◽  
Carbapenem Resistant ◽  
Genes Encoding ◽  
Phenotypic Tests ◽  
Lactamase Gene ◽  
Sequence Types

Ten carbapenem-resistant Enterobacteriaceae (eight Klebsiella pneumoniae isolates and two Enterobacter cloacae) isolates from Yemen were investigated using in vitro antimicrobial susceptibility testing, phenotypic carbapenemase detection, multilocus sequence typing (MLST) and replicon typing. Carbapenemase, extended-spectrum β-lactamase (ESBL) and plasmid-mediated quinolone resistance determinant genes were identified using PCR and sequencing. All of the 10 carbapenem-resistant Enterobacteriaceae were resistant to β-lactams, tobramycin, ciprofloxacin and cotrimoxazole. Imipenem, doripenem and meropenem MICs ranged from 2 to >32 mg l−1 and ertapenem MICs ranged from 6 to >32 mg l−1. All of the K. pneumoniae isolates showed ESBL activity in phenotypic tests. Genes encoding bla NDM were detected in all strains. All K. pneumoniae strains produced CTX-M-15 ESBL and SHV β-lactamases. TEM-1 β-lactamase was detected in seven isolates. Nine isolates were qnr positive including QnrB1, QnrA1 and QnrS1, and six isolates produced AAC-6′-Ib-cr. MLST identified five different sequence types (STs): ST1399, ST147, ST29, ST405 and ST340. Replicon typing showed the presence of IncFII1K plasmids in four transformants. To the best of our knowledge, this is the first report of NDM-1-producing Enterobacteriaceae isolates in Yemen.

scholarly journals In Vitro Activity of Cefepime against Multidrug-Resistant Gram-Negative Bacilli, Viridans Group Streptococci andStreptococcus pneumoniaefrom a Cross-Canada Surveillance Study

1999 ◽  
Vol 10 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Donald E Low ◽  
Joyce de Azavedo ◽  
Canadian Bacterial Surveillance Network ◽  
Ross Davidson
Keyword(s):  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Surveillance Study ◽  
National Committee ◽  
In Vitro Activity ◽  
Gram Negative ◽  
Resistance Rates ◽  
Viridans Group Streptococci

OBJECTIVE: To determine the in vitro activity of cefepime against multidrug-resistant Gram-negative bacilli and Gram-positive cocci obtained from an ongoing cross-Canada surveillance study.DESIGN: Clinical isolates of aerobic Gram-negative bacilli with inducible and constitutive chromosomally mediated cephalosporinases, viridans group streptococci andStreptococcus pneumoniaewere collected from laboratories serving hospitals, nursing homes and physician offices in the community from across Canada during 1996 and 1997. Laboratories were asked to submit only clinically relevant nonduplicate isolates for susceptibility testing. In vitro antimicrobial susceptibility testing was carried out on all isolates of Gram-negative and viridans group streptococci.S pneumoniaewere characterized as penicillin susceptible, intermediately resistant or highly resistant. Nonsusceptible isolates were defined as being intermediately or highly resistant (minimal inhibitory concentrations [MIC] greater than 0.06 mg/L). Only isolates ofS pneumoniaethat were nonsusceptible to penicillin were selected for further study. MICs were determined using a microbroth dilution technique according to the National Committee of Clinical Laboratory Standards.RESULTS: A total of 727 Gram-negative bacilli samples were collected. No resistance to cefepime was detected withCitrobacter freundii,Serratia marcescens,Morganella morganiiandEnterobacterspecies. Of these strains,Enterobacterspecies andC freundiiwere the most resistant to ceftazidime, cefotaxime and ceftriaxone with MIC90Sof 32 mg/L or greater and resistance rates of 6% or greater. Resistance rates ofPseudomonas aeruginosaandAcinetobacterspecies to cefepime were 4.8% and 3%, respectively. The two organisms had similar rates of resistance to ceftazidime. Less than 3% of the Gram-negative bacilli were resistant to imipenem and meropenem. There were 153 viridans group streptococci, of which 22 (14.4%) were resistant to penicillin. Of 1287S pneumoniaesamples, 193 (15%) were nonsusceptible to penicillin. Cefepime, ceftriaxone and cefotaxime had comparable activity against all isolates of viridans group streptococci andS pneumoniae.CONCLUSIONS: Cefepime demonstrated excellent in vitro activity against Gram-negative bacilli with inducible and constitutive chromosomally mediated cephalosporinases, and had equal or superior activity versus comparator beta-lactams against all isolates of viridans group streptococci andS pneumoniae.

scholarly journals Tetracycline Susceptibility Testing and Resistance Genes in Isolates of Acinetobacter baumannii-Acinetobacter calcoaceticus Complex from a U.S. Military Hospital

2009 ◽  
Vol 53 (6) ◽  
pp. 2693-2695 ◽  
Author(s):  
Kevin S. Akers ◽  
Katrin Mende ◽  
Heather C. Yun ◽  
Duane R. Hospenthal ◽  
Miriam L. Beckius ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Tetracycline Resistance ◽  
Acinetobacter Calcoaceticus ◽  
Multidrug Resistant ◽  
Military Hospital ◽  
Tetracycline Resistance Genes ◽  
Testing Method

ABSTRACT Infections with multidrug-resistant Acinetobacter baumannii-Acinetobacter calcoaceticus complex bacteria complicate the care of U.S. military personnel and civilians worldwide. One hundred thirty-three isolates from 89 patients at our facility during 2006 and 2007 were tested by disk diffusion, Etest, and broth microdilution for susceptibility to tetracycline, doxycycline, minocycline, and tigecycline. Minocycline was the most active in vitro, with 90% of the isolates tested susceptible. Susceptibilities varied significantly with the testing method. The acquired tetracycline resistance genes tetA, tetB, and tetA(39) were present in the isolates.

scholarly journals Polyamine Depletion Abrogates Enterovirus Cellular Attachment

2019 ◽  
Vol 93 (20) ◽  
Author(s):  
Thomas M. Kicmal ◽  
Patrick M. Tate ◽  
Courtney N. Dial ◽  
Jeremy J. Esin ◽  
Bryan C. Mounce
Keyword(s):  
Rna Viruses ◽  
Severe Disease ◽  
Coxsackievirus B3 ◽  
Human Pathogens ◽  
Polyamine Biosynthesis ◽  
Virus Attachment ◽  
Significant Public Health ◽  
Approved Drugs

ABSTRACT Polyamines are small polycationic molecules with flexible carbon chains that are found in all eukaryotic cells. Polyamines are involved in the regulation of many host processes and have been shown to be implicated in viral replication. Depletion of polyamine pools in cells treated with FDA-approved drugs restricts replication of diverse RNA viruses. Viruses can exploit host polyamines to facilitate nucleic acid packaging, transcription, and translation, but other mechanisms remain largely unknown. Picornaviruses, including Coxsackievirus B3 (CVB3), are sensitive to the depletion of polyamines and remain a significant public health threat. We employed CVB3 as a model system to investigate a potential proviral role for polyamines using a forward screen. Passaging CVB3 in polyamine-depleted cells generated a mutation in capsid protein VP3 at residue 234. We show that this mutation confers resistance to polyamine depletion. Through attachment assays, we demonstrate that polyamine depletion limits CVB3 attachment to susceptible cells, which is rescued by incubating virus with polyamines. Furthermore, the capsid mutant rescues this inhibition in polyamine-depleted cells. More divergent viruses also exhibited reduced attachment to polyamine-depleted cells, suggesting that polyamines may facilitate attachment of diverse RNA viruses. These studies inform additional mechanisms of action for polyamine-depleting pharmaceuticals, with implications for potential antiviral therapies. IMPORTANCE Enteroviruses are significant human pathogens that can cause severe disease. These viruses rely on polyamines, small positively charged molecules, for robust replication, and polyamine depletion limits infection in vitro and in vivo. The mechanisms by which polyamines enhance enteroviral replication are unknown. Here, we describe how Coxsackievirus B3 (CVB3) utilizes polyamines to attach to susceptible cells and initiate infection. Using a forward genetic screen, we identified a mutation in a receptor-binding amino acid that promotes infection of polyamine-depleted cells. These data suggest that pharmacologically inhibiting polyamine biosynthesis may combat virus infection by preventing virus attachment to susceptible cells.

scholarly journals Persistent Bacteremia fromPseudomonas aeruginosawithIn VitroResistance to the Novel Antibiotics Ceftolozane-Tazobactam and Ceftazidime-Avibactam

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Louie Mar Gangcuangco ◽  
Patricia Clark ◽  
Cynthia Stewart ◽  
Goran Miljkovic ◽  
Zane K. Saul
Keyword(s):  
Susceptibility Testing ◽  
Resistance Mechanism ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Blood Cultures ◽  
The Novel ◽  
First Case ◽  
Persistent Bacteremia ◽  
Novel Antibiotics

Ceftazidime-avibactam and ceftolozane-tazobactam are new antimicrobials with activity against multidrug-resistantPseudomonas aeruginosa. We present the first case of persistentP.aeruginosabacteremia within vitroresistance to these novel antimicrobials. A 68-year-old man with newly diagnosed follicular lymphoma was admitted to the medical intensive care unit for sepsis and right lower extremity cellulitis. The patient was placed empirically on vancomycin and piperacillin-tazobactam. Blood cultures from Day 1 of hospitalization grewP.aeruginosasusceptible to piperacillin-tazobactam and cefepime identified using VITEK 2 (Biomerieux, Lenexa, KS). Repeat blood cultures from Day 5 grewP.aeruginosaresistant to all cephalosporins, as well as to meropenem by Day 10. Susceptibility testing performed by measuring minimum inhibitory concentration byE-test (Biomerieux, Lenexa, KS) revealed that blood cultures from Day 10 were resistant to ceftazidime-avibactam and ceftolozane-tazobactam. The Verigene Blood Culture-Gram-Negative (BC-GN) microarray-based assay (Nanosphere, Inc., Northbrook, IL) was used to investigate underlying resistance mechanism in theP.aeruginosaisolate but CTX-M, KPC, NDM, VIM, IMP, and OXA gene were not detected. This case report highlights the well-documented phenomenon of antimicrobial resistance development inP.aeruginosaeven during the course of appropriate antibiotic therapy. In the era of increasing multidrug-resistant organisms, routine susceptibility testing ofP. aeruginosato ceftazidime-avibactam and ceftolozane-tazobactam is warranted. Emerging resistance mechanisms to these novel antibiotics need to be further investigated.

Prevalence and Antimicrobial Resistance of Salmonella Isolates Recovered from Retail Pork in Major Village Markets in Tai'an Region, China

2017 ◽  
Vol 80 (10) ◽  
pp. 1635-1640 ◽  
Author(s):  
Zengmin Miao ◽  
Song Li ◽  
Kun Qin ◽  
Yufa Zhou
Keyword(s):  
Antimicrobial Resistance ◽  
Broad Spectrum ◽  
Antimicrobial Susceptibility ◽  
Multilocus Sequence Typing ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Contamination Rate ◽  
Sequence Types ◽  
Pork Samples

ABSTRACT The current study was undertaken to evaluate Salmonella contamination in retail pork at major village markets of the Tai'an region, China. In total, 200 retail pork samples were collected from four village markets between June 2015 and February 2016, of which 69 samples (34.5%) were determined to be positive for Salmonella. Eleven serotypes were identified from the 69 Salmonella isolates, and Salmonella Derby was the most common (18 of 69, 26.1%), followed by Typhimurium (17 of 69, 24.6%) and Meleagridis (11 of 69, 15.9%). Antimicrobial susceptibility testing showed that antimicrobial resistance against tetracycline was the most prevalent (42 of 69, 60.9%), but antimicrobial resistance against both ceftriaxone and cefotaxime was 1.4% (1 of 69) and 2.9% (2 of 69), respectively. Multilocus sequence typing revealed that the 69 Salmonella isolates were divided into 11 sequence types (STs), among which ST40 (18 of 69, 26.1%) was the most common, followed by ST34 (15 of 69, 21.7%) and ST64 (13 of 69, 18.8%). Collectively, retail pork at village markets in the Tai'an region has a high Salmonella contamination rate, and these isolates exhibit broad-spectrum antimicrobial resistance. However, the absence of a dominant ST demonstrates that the Salmonella isolates from retail pork may be of diverse origins.

scholarly journals Distribution and Antimicrobial Resistance of Salmonella Isolated from Pigs with Diarrhea in China

2018 ◽  
Vol 6 (4) ◽  
pp. 117 ◽  
Author(s):  
Jin-Hui Su ◽  
Yao-Hong Zhu ◽  
Tian-Yi Ren ◽  
Liang Guo ◽  
Gui-Yan Yang ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Clonal Expansion ◽  
Multidrug Resistant ◽  
High Similarity ◽  
Enteric Diseases ◽  
Antimicrobial Resistance Genes ◽  
Wide Range ◽  
Sequence Types

Salmonella can cause enteric diseases in humans and a wide range of animals, and even outbreaks of foodborne illness. The aim of this study was to investigate the frequency and distribution of serovars, and antimicrobial resistance in Salmonella isolates from pigs with diarrhea in 26 provinces in China from 2014 to 2016. A total of 104 Salmonella isolates were identified and the dominant serovar was S. 4,[5],12:i:- (53.9%). All Salmonella isolates were resistant to trimethoprim-sulfamethoxazole, and many were resistant to ampicillin (80.8%) and tetracycline (76.9%). Among 104 Salmonella isolates, aac(6′)-Ib-cr was the dominant plasmid-mediated quinolone resistance gene (80.8%), followed by qnrS (47.1%). The pulsed-field gel electrophoresis results suggest that the Salmonella isolates from different regions were genetically diverse, and ST34 was the most prevalent. S. 4,[5],12:i:- isolates is the widespread presence of heavy metal tolerance genes. The fact that the same sequence types were found in different regions and the high similarity coefficient of S. 4,[5],12:i:- isolates from different regions indicate the clonal expansion of the isolates, and the isolates carried various antimicrobial resistance genes. The multidrug resistant Salmonella can be widely detected in pigs, which will present a challenge for farm husbandry.

scholarly journals Occurrence of Pseudomonas spp. in Raw Vegetables: Molecular and Phenotypical Analysis of Their Antimicrobial Resistance and Virulence-Related Traits

2021 ◽  
Vol 22 (23) ◽  
pp. 12626
Author(s):  
Lidia Ruiz-Roldán ◽  
Beatriz Rojo-Bezares ◽  
Carmen Lozano ◽  
María López ◽  
Gabriela Chichón ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Insertion Sequence ◽  
Multidrug Resistant ◽  
Pulsed Field Gel Electrophoresis ◽  
Plant Diseases ◽  
Resistant Isolate ◽  
Ecological Niches ◽  
Great Capacity ◽  
Pseudomonas Spp ◽  
Sequence Types

Pseudomonas is characterized by its great capacity to colonize different ecological niches, but also by its antimicrobial resistance and pathogenicity, causing human, animal, or plant diseases. Raw and undercooked food is a potential carrier of foodborne disease. The aim of this study was to determine the occurrence of Pseudomonas spp. among raw vegetables, analysing their antimicrobial resistance, virulence, and molecular typing. A total of 163 Pseudomonas spp. isolates (12 different species) were recovered from 77 of the 145 analysed samples (53.1%) and were classified into 139 different pulsed-field gel electrophoresis patterns. Low antimicrobial resistance levels, but one multidrug-resistant isolate, were found. Among the 37 recovered P. aeruginosa strains, 28 sequence-types and nine serotypes were detected. Eleven OprD patterns and an insertion sequence (ISPa1635) truncating the oprD gene of one imipenem-resistant strain were found. Ten virulotypes were observed, including four exoU-positive and thirty-one exoS-positive strains. The lasR gene was absent in three ST155 strains and was truncated by different insertion sequences (ISPre2, IS1411, and ISPst7) in other three strains. High biofilm, motility, pigment, elastase, and rhamnolipid production were detected. Our study demonstrated a low occurrence of P. aeruginosa (18%) and low antimicrobial resistance, but a high number of virulence-related traits in these P. aeruginosa strains, highlighting their pathological importance.

scholarly journals In Vitro Susceptibility of Multidrug Resistant Strains of Salmonella to Essential Oils

2020 ◽  
Vol 15 (1) ◽  
pp. 1934578X1987890
Author(s):  
Valeria Listorti ◽  
Roberta Battistini ◽  
Carlo Ercolini ◽  
Clara Tramuta ◽  
Elisabetta Razzuoli ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Essential Oils ◽  
Multidrug Resistant ◽  
Animal Origin ◽  
Diffusion Method ◽  
Thymus Vulgaris ◽  
In Vitro Susceptibility ◽  
Resistant Strains

Antimicrobial resistance has become a global threat to public health. There is a critical need to find new antimicrobial substances from natural sources. The aim of this study was to investigate the antimicrobial activity of essential oils (EOs) obtained from Origanum vulgare, Thymus serpyllum, Thymus vulgaris, and Melaleuca alternifolia against multidrug resistant strains of Salmonella isolated from samples of diverse animal origin. The strains were biochemically identified, serotyped, and characterized for their antimicrobial resistance profiles. The antimicrobial activity of the EOs against the strains was evaluated using the Kirby-Bauer diffusion method, followed by determination of the minimal inhibitory concentration and minimum bactericidal concentrations. The EOs of T. serpyllum and O. vulgare, which contain carvacrol as the main compound, show excellent antimicrobial activity.

scholarly journals Virulence Potential of a Multidrug-Resistant Escherichia coli Strain Belonging to the Emerging Clonal Group ST101-B1 Isolated from Bloodstream Infection

2020 ◽  
Vol 8 (6) ◽  
pp. 827 ◽  
Author(s):  
Ana Carolina M. Santos ◽  
Rosa M. Silva ◽  
Tiago B. Valiatti ◽  
Fernanda F. Santos ◽  
José F. Santos-Neto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Bloodstream Infection ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Pathogenic Potential ◽  
E Coli ◽  
Antimicrobial Resistance Genes

Escherichia coli EC121 is a multidrug-resistant (MDR) strain isolated from a bloodstream infection of an inpatient with persistent gastroenteritis and T-zone lymphoma that died due to septic shock. Despite causing an extraintestinal infection, previous studies showed that it did not have the usual characteristics of an extraintestinal pathogenic E. coli. Instead, it belonged to phylogenetic group B1 and harbored few known virulence genes. To evaluate the pathogenic potential of strain EC121, an extensive genome sequencing and in vitro characterization of various pathogenicity-associated properties were performed. The genomic analysis showed that strain EC121 harbors more than 50 complete virulence genetic clusters. It also displays the capacity to adhere to a variety of epithelial cell lineages and invade T24 bladder cells, as well as the ability to form biofilms on abiotic surfaces, and survive the bactericidal serum complement activity. Additionally, EC121 was shown to be virulent in the Galleria mellonella model. Furthermore, EC121 is an MDR strain harboring 14 antimicrobial resistance genes, including blaCTX-M-2. Completing the scenario, it belongs to serotype O154:H25 and to sequence type 101-B1, which has been epidemiologically linked to extraintestinal infections as well as to antimicrobial resistance spread. This study with E. coli strain EC121 shows that clinical isolates considered opportunistic might be true pathogens that go underestimated.

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