scholarly journals Identification and Characterization of Salmonella enterica Serotype Newport Isolates with Decreased Susceptibility to Ciprofloxacin in the United States

2018 ◽  
Vol 62 (7) ◽  
pp. e00653-18 ◽  
Author(s):  
D. Campbell ◽  
K. Tagg ◽  
A. Bicknese ◽  
A. McCullough ◽  
J. Chen ◽  
...  
Keyword(s):  
United States ◽  
Salmonella Enterica ◽  
The United States ◽  
Quinolone Resistance ◽  
Content Type ◽  
Chromosomal Mutations ◽  
Identification And Characterization

ABSTRACT Nontyphoidal Salmonella (NTS) causes an estimated 1.2 million illnesses, 23,000 hospitalizations, and 450 deaths each year in the United States. Decreased susceptibility to ciprofloxacin (DSC) has historically been associated with chromosomal mutations of the quinolone resistance determining region (QRDR), but plasmid-mediated quinolone resistance (PMQR) genes are increasing. To investigate DSC among Salmonella enterica serotype Newport strains, we examined 40 isolates from 1996 to 2016 with DSC. Thirty isolates (71%) contained the PMQR gene qnrB and eight isolates (19%) contained a QRDR.

scholarly journals Circulation of Plasmids Harboring Resistance Genes to Quinolones and/or Extended-Spectrum Cephalosporins in Multiple Salmonella enterica Serotypes from Swine in the United States

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Ehud Elnekave ◽  
Samuel L. Hong ◽  
Seunghyun Lim ◽  
Shivdeep S. Hayer ◽  
Dave Boxrud ◽  
...  
Keyword(s):  
United States ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
De Novo ◽  
Horizontal Transmission ◽  
The United States ◽  
Content Type ◽  
Extended Spectrum ◽  
Antimicrobial Resistance Genes ◽  
Chromosomal Mutations

ABSTRACT Nontyphoidal Salmonella enterica (NTS) poses a major public health risk worldwide that is amplified by the existence of antimicrobial-resistant strains, especially those resistant to quinolones and extended-spectrum cephalosporins (ESC). Little is known on the dissemination of plasmids harboring the acquired genetic determinants that confer resistance to these antimicrobials across NTS serotypes from livestock in the United States. NTS isolates (n = 183) from U.S. swine clinical cases retrieved during 2014 to 2016 were selected for sequencing based on their phenotypic resistance to enrofloxacin (quinolone) or ceftiofur (3rd-generation cephalosporin). De novo assemblies were used to identify chromosomal mutations and acquired antimicrobial resistance genes (AARGs). In addition, plasmids harboring AARGs were identified using short-read assemblies and characterized using a multistep approach that was validated by long-read sequencing. AARGs to quinolones [qnrB15, qnrB19, qnrB2, qnrD, qnrS1, qnrS2, and aac(6')Ib-cr] and ESC (blaCMY-2, blaCTX-M-1, blaCTX-M-27, and blaSHV-12) were distributed across serotypes and were harbored by several plasmids. In addition, chromosomal mutations associated with resistance to quinolones were identified in the target enzyme and efflux pump regulation genes. The predominant plasmid harboring the prevalent qnrB19 gene was distributed across serotypes. It was identical to a plasmid previously reported in S. enterica serovar Anatum from swine in the United States (GenBank accession number KY991369.1) and similar to Escherichia coli plasmids from humans in South America (GenBank accession numbers GQ374157.1 and JN979787.1). Our findings suggest that plasmids harboring AARGs encoding mechanisms of resistance to critically important antimicrobials are present in multiple NTS serotypes circulating in swine in the United States and can contribute to resistance expansion through horizontal transmission.

scholarly journals Antimicrobial Susceptibility to Azithromycin among Salmonella enterica Isolates from the United States

2011 ◽  
Vol 55 (9) ◽  
pp. 3985-3989 ◽  
Author(s):  
Maria Sjölund-Karlsson ◽  
Kevin Joyce ◽  
Karen Blickenstaff ◽  
Takiyah Ball ◽  
Jovita Haro ◽  
...  
Keyword(s):  
United States ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Antimicrobial Agents ◽  
The United States ◽  
Outcome Data ◽  
Content Type ◽  
Susceptibility Data ◽  
Retail Meat ◽  
Clinical Breakpoints

ABSTRACTDue to emerging resistance to traditional antimicrobial agents, such as ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol, azithromycin is increasingly used for the treatment of invasiveSalmonellainfections. In the present study, 696 isolates of non-TyphiSalmonellacollected from humans, food animals, and retail meats in the United States were investigated for antimicrobial susceptibility to azithromycin. Seventy-twoSalmonella entericaserotype Typhi isolates from humans were also tested. For each isolate, MICs of azithromycin and 15 other antimicrobial agents were determined by broth microdilution. Among the non-TyphiSalmonellaisolates, azithromycin MICs among human isolates ranged from 1 to 32 μg/ml, whereas the MICs among the animal and retail meat isolates ranged from 2 to 16 μg/ml and 4 to 16 μg/ml, respectively. AmongSalmonellaserotype Typhi isolates, the azithromycin MICs ranged from 4 to 16 μg/ml. The highest MIC observed in the present study was 32 μg/ml, and it was detected in three human isolates belonging to serotypes Kentucky, Montevideo, and Paratyphi A. Based on our findings, we propose an epidemiological cutoff value (ECOFF) for wild-typeSalmonellaof ≤16 μg/ml of azithromycin. The susceptibility data provided could be used in combination with clinical outcome data to determine tentative clinical breakpoints for azithromycin andSalmonella enterica.

scholarly journals Role of Antilipopolysaccharide Antibodies in Serum Bactericidal Activity against Salmonella enterica Serovar Typhimurium in Healthy Adults and Children in the United States

2013 ◽  
Vol 20 (10) ◽  
pp. 1491-1498 ◽  
Author(s):  
Estela Trebicka ◽  
Susan Jacob ◽  
Waheed Pirzai ◽  
Bryan P. Hurley ◽  
Bobby J. Cherayil
Keyword(s):  
United States ◽  
Bactericidal Activity ◽  
Salmonella Enterica ◽  
The United States ◽  
Healthy Children ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Content Type ◽  
Serovar Typhimurium

ABSTRACTRecent observations from Africa have rekindled interest in the role of serum bactericidal antibodies in protecting against systemic infection withSalmonella entericaserovar Typhimurium. To determine whether the findings are applicable to other populations, we analyzed serum samples collected from healthy individuals in the United States. We found that all but 1 of the 49 adult samples tested had robust bactericidal activity againstS. Typhimurium in a standardin vitroassay. The activity was dependent on complement and could be reproduced by immunoglobulin G (IgG) purified from the sera. The bactericidal activity was inhibited by competition with soluble lipopolysaccharide (LPS) fromS. Typhimurium but not fromEscherichia coli, consistent with recognition of a determinant in the O-antigen polysaccharide. Sera from healthy children aged 10 to 48 months also had bactericidal activity, although it was significantly less than in the adults, correlating with lower levels of LPS-specific IgM and IgG. The lone sample in our collection that lacked bactericidal activity was able to inhibit killing ofS. Typhimurium by the other sera. The inhibition correlated with the presence of an LPS-specific IgM and was associated with decreased complement deposition on the bacterial surface. Our results indicate that healthy individuals can have circulating antibodies to LPS that either mediate or inhibit killing ofS. Typhimurium. The findings contrast with the observations from Africa, which linked bactericidal activity to antibodies against anS. Typhimurium outer membrane protein and correlated the presence of inhibitory anti-LPS antibodies with human immunodeficiency virus infection.

scholarly journals An Attenuated Salmonella enterica Serovar Typhimurium Strain and Galacto-Oligosaccharides Accelerate Clearance of Salmonella Infections in Poultry through Modifications to the Gut Microbiome

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
M. Andrea Azcarate-Peril ◽  
Natasha Butz ◽  
Maria Belen Cadenas ◽  
Matthew Koci ◽  
Anne Ballou ◽  
...  
Keyword(s):  
United States ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Salmonella Enterica ◽  
The United States ◽  
Wild Type ◽  
Content Type ◽  
Salmonella Infections ◽  
Serovar Typhimurium ◽  
The Impact

ABSTRACT Salmonella is estimated to cause one million foodborne illnesses in the United States every year. Salmonella -contaminated poultry products are one of the major sources of salmonellosis. Given the critical role of the gut microbiota in Salmonella transmission, a manipulation of the chicken intestinal microenvironment could prevent animal colonization by the pathogen. In Salmonella , the global regulator gene fnr ( f umarate n itrate r eduction) regulates anaerobic metabolism and is essential for adapting to the gut environment. This study tested the hypothesis that an attenuated Fnr mutant of Salmonella enterica serovar Typhimurium (attST) or prebiotic galacto-oligosaccharides (GOS) could improve resistance to wild-type Salmonella via modifications to the structure of the chicken gut microbiome. Intestinal samples from a total of 273 animals were collected weekly for 9 weeks to evaluate the impact of attST or prebiotic supplementation on microbial species of the cecum, duodenum, jejunum, and ileum. We next analyzed changes to the gut microbiome induced by challenging the animals with a wild-type Salmonella serovar 4,[5],12:r:− (Nal r ) strain and determined the clearance rate of the virulent strain in the treated and control groups. Both GOS and the attenuated Salmonella strain modified the gut microbiome but elicited alterations of different taxonomic groups. The attST produced significant increases of Alistipes and undefined Lactobacillus , while GOS increased Christensenellaceae and Lactobacillus reuteri . The microbiome structural changes induced by both treatments resulted in a faster clearance after a Salmonella challenge. IMPORTANCE With an average annual incidence of 13.1 cases/100,000 individuals, salmonellosis has been deemed a nationally notifiable condition in the United States by the Centers for Disease Control and Prevention (CDC). Earlier studies demonstrated that Salmonella is transmitted by a subset of animals (supershedders). The supershedder phenotype can be induced by antibiotics, ascertaining an essential role for the gut microbiota in Salmonella transmission. Consequently, modulation of the gut microbiota and modification of the intestinal microenvironment could assist in preventing animal colonization by the pathogen. Our study demonstrated that a manipulation of the chicken gut microbiota by the administration of an attenuated Salmonella strain or prebiotic galacto-oligosaccharides (GOS) can promote resistance to Salmonella colonization via increases of beneficial microorganisms that translate into a less hospitable gut microenvironment.

scholarly journals Antimicrobial Resistance in Salmonella in the United States from 1948 to 1995

2016 ◽  
Vol 60 (4) ◽  
pp. 2567-2571 ◽  
Author(s):  
Daniel A. Tadesse ◽  
Aparna Singh ◽  
Shaohua Zhao ◽  
Mary Bartholomew ◽  
Niketta Womack ◽  
...  
Keyword(s):  
United States ◽  
Retrospective Study ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Antimicrobial Agents ◽  
The United States ◽  
Content Type ◽  
The Past ◽  
The 1950S

ABSTRACTWe conducted a retrospective study of 2,149 clinicalSalmonellastrains to help document the historical emergence of antimicrobial resistance. There were significant increases in resistance to older drugs, including ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline, which were most common inSalmonella entericaserotype Typhimurium. An increase in multidrug resistance was observed for each decade since the 1950s. These data help show howSalmonellaevolved over the past 6 decades, after the introduction of new antimicrobial agents.

scholarly journals Molecular Characterization of a Voriconazole-Resistant, Posaconazole-Susceptible Aspergillus fumigatus Isolate in a Lung Transplant Recipient in the United States

2015 ◽  
Vol 60 (2) ◽  
pp. 1129-1133 ◽  
Author(s):  
Jose A. Vazquez ◽  
Elias K. Manavathu
Keyword(s):  
United States ◽  
Aspergillus Fumigatus ◽  
Molecular Characterization ◽  
Lung Transplant ◽  
Transplant Patient ◽  
The United States ◽  
Azole Resistance ◽  
Content Type ◽  
High Level

ABSTRACTMolecular characterization ofcyp51Afrom the azole-resistantAspergillus fumigatusisolate 50593 from a lung transplant patient showed Y121F/T289A changes coupled with a 46-bp tandem repeat (TR46) on the promoter, whereascyp51Afrom the pretherapy isolate,A. fumigatus47381, showed no changes. This is the first reported case ofA. fumigatusazole resistance due to Y121F/T289A/TR46 in the United States, suggesting that multiple mutational alterations ofcyp51Aresulting in high-level azole resistance could occur during prolonged antifungal therapy.

scholarly journals Genetic Characterization of Escherichia coli O104 Isolates from Different Sources in the United States

2011 ◽  
Vol 78 (5) ◽  
pp. 1615-1618 ◽  
Author(s):  
Lydia V. Rump ◽  
Sonya Bodeis-Jones ◽  
Jason Abbott ◽  
Shaohua Zhao ◽  
Julie Kase ◽  
...  
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Virulence Genes ◽  
Genetic Characterization ◽  
The United States ◽  
Content Type ◽  
E Coli ◽  
Virulence Markers ◽  
Different Sources

ABSTRACTEscherichia coliO104 isolates collected from different sources in the United States were examined for virulence genes typical of enterohemorrhagicE. coliand those identified in the O104:H4 isolate associated with the 2011 German outbreak. The unexpected presence of virulence markers in these isolates highlights the importance of screening unusual and potentially pathogenic Shiga toxin-producingE. coliserotypes.

scholarly journals Emergence of Plasmid-Mediated Quinolone Resistance among Non-Typhi Salmonella enterica Isolates from Humans in the United States

2009 ◽  
Vol 53 (5) ◽  
pp. 2142-2144 ◽  
Author(s):  
Maria Sjölund-Karlsson ◽  
Jason P. Folster ◽  
Gary Pecic ◽  
Kevin Joyce ◽  
Felicita Medalla ◽  
...  
Keyword(s):  
United States ◽  
Retrospective Study ◽  
Salmonella Enterica ◽  
The United States ◽  
Quinolone Resistance ◽  
Gram Negative ◽  
Resistance Determinants

ABSTRACT Plasmid-mediated quinolone resistance determinants are emerging among gram-negative pathogens. Here we report results of a retrospective study investigating the prevalence of aac(6′)-Ib-cr, qepA, and qnr genes among 19,010 human isolates of non-Typhi Salmonella enterica collected in the United States from 1996 to 2006.

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