scholarly journals Strain Types and Antimicrobial Resistance Patterns of Clostridium difficile Isolates from the United States, 2011 to 2013

2014 ◽  
Vol 58 (7) ◽  
pp. 4214-4218 ◽  
Author(s):  
Isabella A. Tickler ◽  
Richard V. Goering ◽  
Joseph D. Whitmore ◽  
Ashley N. W. Lynn ◽  
David H. Persing ◽  
...  
Keyword(s):  
United States ◽  
Clostridium Difficile ◽  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
The United States ◽  
Geographic Region ◽  
Content Type ◽  
Resistance Patterns ◽  
Strain Type ◽  
Susceptibility Patterns

ABSTRACTWe determined the PCR ribotypes and antimicrobial susceptibility patterns of 508 toxigenicClostridium difficileisolates collected between 2011 and 2013 from 32 U.S. hospitals. Of the 29 PCR ribotypes identified, the 027 strain type was the most common (28.1%), although the rates varied by geographic region. Ribotype 014/020 isolates appear to be emerging. Clindamycin and moxifloxacin resistances (36.8% and 35.8%, respectively) were the most frequent resistance phenotypes observed. Reduced susceptibility to vancomycin was observed in 39.1% of 027 isolates.

scholarly journals Pediatric Antimicrobial Susceptibility Trends across the United States

2013 ◽  
Vol 34 (12) ◽  
pp. 1244-1251 ◽  
Author(s):  
Pranita D. Tamma ◽  
Gwen L. Robinson ◽  
Jeffrey S. Gerber ◽  
Jason G. Newland ◽  
Chloe M. DeLisle ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
The United States ◽  
Methicillin Resistant ◽  
Resistance Patterns ◽  
Gram Negative Organisms ◽  
Pediatric Healthcare ◽  
Regional Comparisons ◽  
Susceptibility Patterns ◽  
Over Time

Objective.Antimicrobial susceptibility patterns across US pediatric healthcare institutions are unknown. A national pooled pediatric antibiogram (1) identifies nationwide trends in antimicrobial resistance, (2) allows across-hospital benchmarking, and (3) provides guidance for empirical antimicrobial regimens for institutions unable to generate pediatric antibiograms.Methods.In January 2012, a request for submission of pediatric antibiograms between 2005 and 2011 was sent to 233 US hospitals. A summary antibiogram was compiled from participating institutions to generate proportions of antimicrobial susceptibility. Temporal and regional comparisons were evaluated using χ² tests and logistic regression, respectively.Results.Of 200 institutions (85%) responding to our survey, 78 (39%) reported generating pediatric antibiograms, and 55 (71%) submitted antibiograms. Carbapenems had the highest activity against the majority of gram-negative organisms tested, but no antibiotic had more than 90% activity against Pseudomonas aeruginosa. Approximately 50% of all Staphylococcus aureus isolates were methicillin resistant. Western hospitals had significantly lower proportions of S. aureus that were methicillin resistant compared with all other regions tested. Overall, 21% of S. aureus isolates had resistance to clindamycin. Among Enterococcus faecium isolates, the prevalence of susceptibility to ampicillin (25%) and vancomycin (45%) was low but improved over time (P < .01), and 8% of E. faecium isolates were resistant to linezolid. Southern hospitals reported significantly higher prevalence of E. faecium with susceptibilities to ampicillin, vancomycin, and linezolid compared with the other 3 regions (P < .01).Conclusions.A pooled, pediatric antibiogram can identify nationwide antimicrobial resistance patterns for common pathogens and might serve as a useful tool for benchmarking resistance and informing national prescribing guidelines for children.

scholarly journals Need for Annual Surveillance of Antimicrobial Resistance in Streptococcus pneumoniae in the United States: 2-Year Longitudinal Analysis

2001 ◽  
Vol 45 (4) ◽  
pp. 1037-1042 ◽  
Author(s):  
Daniel F. Sahm ◽  
James A. Karlowsky ◽  
Laurie J. Kelly ◽  
Ian A. Critchley ◽  
Mark E. Jones ◽  
...  
Keyword(s):  
United States ◽  
Streptococcus Pneumoniae ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
The United States ◽  
Multidrug Resistant ◽  
Fluoroquinolone Resistance ◽  
Resistance Patterns ◽  
Changing Patterns ◽  
Resistance To Penicillin

ABSTRACT Although changing patterns in antimicrobial resistance inStreptococcus pneumoniae have prompted several surveillance initiatives in recent years, the frequency with which these studies are needed has not been addressed. To approach this issue, the extent to which resistance patterns change over a 1-year period was examined. In this study we analyzed S. pneumoniaeantimicrobial susceptibility results produced in our laboratory with isolates obtained over 2 consecutive years (1997–1998 and 1998–1999) from the same 96 institutions distributed throughout the United States. Comparison of results revealed increases in resistant percentages for all antimicrobial agents studied except vancomycin. For four of the agents tested (penicillin, cefuroxime, trimethoprim-sulfamethoxazole, and levofloxacin), the increases were statistically significant (P < 0.05). Resistance to the fluoroquinolone remained low in both years (0.1 and 0.6%, respectively); in contrast, resistance to macrolides was consistently greater than 20%, and resistance to trimethoprim-sulfamethoxazole increased from 13.3 to 27.3%. Multidrug resistance, concurrent resistance to three or more antimicrobials of different chemical classes, also increased significantly between years, from 5.9 to 11%. The most prevalent phenotype was resistance to penicillin, azithromycin (representative macrolide), and trimethoprim-sulfamethoxazole. Multidrug-resistant phenotypes that included fluoroquinolone resistance were uncommon; however, two phenotypes that included fluoroquinolone resistance not found in 1997–1998 were encountered in 1998–1999. This longitudinal surveillance study of resistance inS. pneumoniae revealed that significant changes do occur in just a single year and supports the need for surveillance at least on an annual basis, if not continuously.

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 Comparison of Multilocus Sequence Typing and the Xpert C. difficile/Epi Assay for Identification of Clostridium difficile 027/NAP1/BI

2015 ◽  
Vol 54 (3) ◽  
pp. 775-778 ◽  
Author(s):  
Tracy McMillen ◽  
Mini Kamboj ◽  
N. Esther Babady
Keyword(s):  
United States ◽  
Clostridium Difficile ◽  
Confidence Interval ◽  
Multilocus Sequence Typing ◽  
The United States ◽  
Content Type ◽  
Presumptive Identification ◽  
Good Agreement

Clostridium difficile027/NAP1/BI is the most commonC. difficilestrain in the United States. The XpertC. difficile/Epi assay allows rapid, presumptive identification ofC. difficileNAP1. We compared XpertC. difficile/Epi to multilocus sequence typing for identification ofC. difficileNAP1 and found “very good” agreement at 97.9% (κ = 0.86; 95% confidence interval, 0.80 to 0.91).

scholarly journals Antimicrobial Susceptibility Patterns of Brachyspira Species Isolated from Swine Herds in the United States

2016 ◽  
Vol 54 (8) ◽  
pp. 2109-2119 ◽  
Author(s):  
Nandita S. Mirajkar ◽  
Peter R. Davies ◽  
Connie J. Gebhart
Keyword(s):  
United States ◽  
Antimicrobial Susceptibility ◽  
North American ◽  
Bacterial Species ◽  
The United States ◽  
Swine Dysentery ◽  
Content Type ◽  
Brachyspira Pilosicoli ◽  
Swine Herds ◽  
And Control

Outbreaks of swine dysentery, caused byBrachyspira hyodysenteriaeand the recently discovered “Brachyspira hampsonii,” have reoccurred in North American swine herds since the late 2000s. Additionally, multipleBrachyspiraspecies have been increasingly isolated by North American diagnostic laboratories. In Europe, the reliance on antimicrobial therapy for control of swine dysentery has been followed by reports of antimicrobial resistance over time. The objectives of our study were to determine the antimicrobial susceptibility trends of fourBrachyspiraspecies originating from U.S. swine herds and to investigate their associations with the bacterial species, genotypes, and epidemiological origins of the isolates. We evaluated the susceptibility ofB. hyodysenteriae,B. hampsonii,Brachyspira pilosicoli, andBrachyspira murdochiito tiamulin, valnemulin, doxycycline, lincomycin, and tylosin by broth microdilution and that to carbadox by agar dilution. In general,Brachyspiraspecies showed high susceptibility to tiamulin, valnemulin, and carbadox, heterogeneous susceptibility to doxycycline, and low susceptibility to lincomycin and tylosin. A trend of decreasing antimicrobial susceptibility by species was observed (B. hampsonii>B. hyodysenteriae>B. murdochii>B. pilosicoli). In general,Brachyspiraisolates from the United States were more susceptible to these antimicrobials than were isolates from other countries. Decreased antimicrobial susceptibility was associated with the genotype, stage of production, and production system from which the isolate originated, which highlights the roles of biosecurity and husbandry in disease prevention and control. Finally, this study also highlights the urgent need for Clinical and Laboratory Standards Institute-approved clinical breakpoints forBrachyspiraspecies, to facilitate informed therapeutic and control strategies.

scholarly journals Antimicrobial Susceptibility and Clonality of Clinical Ureaplasma Isolates in the United States

2016 ◽  
Vol 60 (8) ◽  
pp. 4793-4798 ◽  
Author(s):  
Javier Fernández ◽  
Melissa J. Karau ◽  
Scott A. Cunningham ◽  
Kerryl E. Greenwood-Quaintance ◽  
Robin Patel
Keyword(s):  
United States ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Ureaplasma Urealyticum ◽  
Resistance Mechanism ◽  
The United States ◽  
Resistance Mechanisms ◽  
Resistant Isolate ◽  
Limited Information ◽  
Content Type

ABSTRACTUreaplasma urealyticumandUreaplasma parvumare pathogens involved in urogenital tract and intrauterine infections and also in systemic diseases in newborns and immunosuppressed patients. There is limited information on the antimicrobial susceptibility and clonality of these species. In this study, we report the susceptibility of 250 contemporary isolates ofUreaplasma(202U. parvumand 48U. urealyticumisolates) recovered at Mayo Clinic, Rochester, MN. MICs of doxycycline, azithromycin, ciprofloxacin, tetracycline, erythromycin, and levofloxacin were determined by broth microdilution, with MICS of the last three interpreted according to CLSI guidelines. Levofloxacin resistance was found in 6.4% and 5.2% ofU. parvumandU. urealyticumisolates, respectively, while 27.2% and 68.8% of isolates, respectively, showed ciprofloxacin MICs of ≥4 μg/ml. The resistance mechanism of levofloxacin-resistant isolates was due to mutations inparC, with the Ser83Leu substitution being most frequent, followed by Glu87Lys. No macrolide resistance was found among the 250 isolates studied; a singleU. parvumisolate was tetracycline resistant.tet(M) was found in 10U. parvumisolates, including the single tetracycline-resistant isolate, as well as in 9 isolates which had low tetracycline and doxycycline MICs. Multilocus sequence typing (MLST) performed on a selection of 46 isolates showed high diversity within the clinicalUreaplasmaisolates studied, regardless of antimicrobial susceptibility. The present work extends previous knowledge regarding susceptibility to antimicrobial agents, resistance mechanisms, and clonality ofUreaplasmaspecies in the United States.

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 Trends in Susceptibility of Escherichia coli from Intra-Abdominal Infections to Ertapenem and Comparators in the United States According to Data from the SMART Program, 2009 to 2013

2015 ◽  
Vol 59 (6) ◽  
pp. 3606-3610 ◽  
Author(s):  
Sibylle H. Lob ◽  
Krystyna M. Kazmierczak ◽  
Robert E. Badal ◽  
Meredith A. Hackel ◽  
Samuel K. Bouchillon ◽  
...  
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Statistical Significance ◽  
The United States ◽  
Multidrug Resistant ◽  
Content Type ◽  
E Coli ◽  
Smart Data ◽  
Abdominal Infections

ABSTRACTAntimicrobial resistance inEnterobacteriaceae, including resistance to carbapenems, is increasing worldwide. However, using U.S. Study for Monitoring Antimicrobial Resistance Trends (SMART) data for 2009 to 2013, no statistically significant decreasing susceptibility trends were found overall forEscherichia coliisolates from patients with intra-abdominal infections. In the subset of isolates from community-associated infections, susceptibility to levofloxacin decreased significantly and the increasing rate of multidrug-resistantE. coliapproached statistical significance. In 2013, ertapenem, imipenem, and amikacin showed the highest susceptibility rates (≥99%) and fluoroquinolones the lowest (<70%). The 10 non-ertapenem-susceptible isolates (0.3% of allE. coliisolates) encoded one or more carbapenemases, extended-spectrum β-lactamases (ESBLs), AmpC β-lactamases, or non-ESBL β-lactamases.

scholarly journals Genomic Analysis of Emerging Florfenicol-Resistant Campylobacter coli Isolated from the Cecal Contents of Cattle in the United States

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Shaohua Zhao ◽  
Sampa Mukherjee ◽  
Chih-Hao Hsu ◽  
Shenia Young ◽  
Cong Li ◽  
...  
Keyword(s):  
United States ◽  
Risk Assessment ◽  
Antimicrobial Resistance ◽  
The United States ◽  
Mitigation Strategies ◽  
Virulence Plasmid ◽  
Campylobacter Coli ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Antimicrobial Resistance Surveillance

ABSTRACT Genomic analyses were performed on florfenicol-resistant (FFNr) Campylobacter coli isolates recovered from cattle, and the cfr(C) gene-associated multidrug resistance (MDR) plasmid was characterized. Sixteen FFNr C. coli isolates recovered between 2013 and 2018 from beef cattle were sequenced using MiSeq. Genomes and plasmids were found to be closed for three of the isolates using the PacBio system. Single nucleotide polymorphisms (SNPs) across the genome and the structures of MDR plasmids were investigated. Conjugation experiments were performed to determine the transferability of cfr(C)-associated MDR plasmids. The spectrum of resistance encoded by the cfr(C) gene was further investigated by agar dilution antimicrobial susceptibility testing. All 16 FFNr isolates were MDR and exhibited coresistance to ciprofloxacin, nalidixic acid, clindamycin, and tetracycline. All isolates shared the same resistance genotype, carrying aph (3′)-III, hph, ΔaadE (truncated), blaOXA-61, cfr(C), and tet(O) genes plus a mutation of GyrA (T86I). The cfr(C), aph (3′)-III, hph, ΔaadE, and tet(O) genes were colocated on transferable MDR plasmids ranging in size from 48 to 50 kb. These plasmids showed high sequence homology with the pTet plasmid and carried several Campylobacter virulence genes, including virB2, virB4, virB5, VirB6, virB7, virB8, virb9, virB10, virB11, and virD4. The cfr(C) gene conferred resistance to florfenicol (8 to 32 μg/ml), clindamycin (512 to 1,024 μg/ml), linezolid (128 to 512 μg/ml), and tiamulin (1,024 μg/ml). Phylogenetic analysis showed SNP differences ranging from 11 to 2,248 SNPs among the 16 isolates. The results showed that the cfr(C) gene located in the conjugative pTet MDR/virulence plasmid is present in diverse strains, where it confers high levels of resistance to several antimicrobials, including linezolid, a critical drug for treating infections by Gram-positive bacteria in humans. This report highlights the power of genomic antimicrobial resistance surveillance to uncover the intricacies of transmissible coresistance and provides information that is needed for accurate risk assessment and mitigation strategies. IMPORTANCE Campylobacter is a leading cause of foodborne diarrheal illness worldwide, with more than one million cases each year in the United States alone. The global emergence of antimicrobial resistance in this pathogen has become a growing public health concern. Florfenicol-resistant (FFNr) Campylobacter has been very rare in the United States. In this study, we employed whole-genome sequencing to characterize 16 multidrug-resistant Campylobacter coli isolates recovered from cattle in the United States. A gene [cfr(C)] was found to be responsible for resistance not only to florfenicol but also to several other antimicrobials, including linezolid, a critical drug for treating infections by Gram-positive bacteria in humans. The results showed that cfr(C) is located in a conjugative pTet MDR/virulence plasmid. This report highlights the power of antimicrobial resistance surveillance to uncover the intricacies of transmissible coresistance and provides information that is needed for accurate risk assessment and mitigation strategies.

Sign in / Sign up

Export Citation Format

Share Document