scholarly journals Prevalence, Enumeration, Serotypes, and Antimicrobial Resistance Phenotypes of Salmonella enterica Isolates from Carcasses at Two Large United States Pork Processing Plants

2012 ◽  
Vol 78 (8) ◽  
pp. 2716-2726 ◽  
Author(s):  
John W. Schmidt ◽  
Dayna M. Brichta-Harhay ◽  
Norasak Kalchayanand ◽  
Joseph M. Bosilevac ◽  
Steven D. Shackelford ◽  
...  

ABSTRACTThe objective of this study was to characterizeSalmonella entericacontamination on carcasses in two large U.S. commercial pork processing plants. The carcasses were sampled at three points, before scalding (prescald), after dehairing/polishing but before evisceration (preevisceration), and after chilling (chilled final). The overall prevalences ofSalmonellaon carcasses at these three sampling points, prescald, preevisceration, and after chilling, were 91.2%, 19.1%, and 3.7%, respectively. At one of the two plants, the prevalence ofSalmonellawas significantly higher (P< 0.01) for each of the carcass sampling points. The prevalences of carcasses with enumerableSalmonellaat prescald, preevisceration, and after chilling were 37.7%, 4.8%, and 0.6%, respectively. A total of 294 prescald carcasses hadSalmonellaloads of >1.9 log CFU/100 cm2, but these carcasses were not equally distributed between the two plants, as 234 occurred at the plant with higherSalmonellaprevalences. Forty-one serotypes were identified on prescald carcasses withSalmonella entericaserotypes Derby, Typhimurium, and Anatum predominating.S. entericaserotypes Typhimurium and London were the most common of the 24 serotypes isolated from preevisceration carcasses. TheSalmonellaserotypes Johannesburg and Typhimurium were the most frequently isolated serotypes of the 9 serotypes identified from chilled final carcasses. Antimicrobial susceptibility was determined for selected isolates from each carcass sampling point. Multiple drug resistance (MDR), defined as resistance to three or more classes of antimicrobial agents, was identified for 71.2%, 47.8%, and 77.5% of the tested isolates from prescald, preevisceration, and chilled final carcasses, respectively. The results of this study indicate that the interventions used by pork processing plants greatly reduce the prevalence ofSalmonellaon carcasses, but MDRSalmonellawas isolated from 3.2% of the final carcasses sampled.

2011 ◽  
Vol 55 (9) ◽  
pp. 3985-3989 ◽  
Author(s):  
Maria Sjölund-Karlsson ◽  
Kevin Joyce ◽  
Karen Blickenstaff ◽  
Takiyah Ball ◽  
Jovita Haro ◽  
...  

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.


2020 ◽  
Vol 48 (10) ◽  
pp. 030006052096229
Author(s):  
Jiachang Liu ◽  
Ruikai Wang ◽  
Ming Fang

Objectives To investigate the clinical and drug resistance characteristics of Providencia stuartii infections in the Huainan region of Anhui and provide a reference for the clinical selection of antimicrobial agents. Methods This single-center retrospective analysis included 76 patients with P. stuartii infection in Huainan during the period from October 2018 to March 2020. The hospital department in which the patients were treated and the drug susceptibility characteristics of the P. stuartii isolates were recorded. Results Among the 76 patients, the lung was the most common site of infection, and intensive care unit was the main hospital department. Extended spectrum beta-lactamase screening revealed expression by all 76 isolates of P. stuartii. Of the 76 isolates, 92.1% exhibited multiple drug resistance or extensive drug resistance. P. stuartii isolates were sensitive to cefepime and imipenem, but not to other beta-lactam antibiotics. Twenty isolates were resistant to all 21 types of antibiotics. Of the 20 patients infected with extensively drug-resistant isolates, nine (45%) died. Conclusions Drug resistance is increasing in P. stuartii. The antimicrobial agent imipenem may be effective for treatment of P. stuartii infections. Fluoroquinolones, aminoglycosides, and fourth-generation cephalosporins are suitable options for antibiotic therapy.


2016 ◽  
Vol 60 (4) ◽  
pp. 2567-2571 ◽  
Author(s):  
Daniel A. Tadesse ◽  
Aparna Singh ◽  
Shaohua Zhao ◽  
Mary Bartholomew ◽  
Niketta Womack ◽  
...  

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.


2019 ◽  
Vol 20 (9) ◽  
pp. 720-741 ◽  
Author(s):  
Ayse Basak Engin ◽  
Atilla Engin

Background: The main drawbacks for using conventional antimicrobial agents are the development of multiple drug resistance due to the use of high concentrations of antibiotics for extended periods. This vicious cycle often generates complications of persistent infections, and intolerable antibiotic toxicity. The problem is that while all new discovered antimicrobials are effective and promising, they remain as only short-term solutions to the overall challenge of drug-resistant bacteria. Objective: Recently, nanoantibiotics (nAbts) have been of tremendous interest in overcoming the drug resistance developed by several pathogenic microorganisms against most of the commonly used antibiotics. Compared with free antibiotic at the same concentration, drug delivered via a nanoparticle carrier has a much more prominent inhibitory effect on bacterial growth, and drug toxicity, along with prolonged drug release. Additionally, multiple drugs or antimicrobials can be packaged within the same smart polymer which can be designed with stimuli-responsive linkers. These stimuli-responsive nAbts open up the possibility of creating multipurpose and targeted antimicrobials. Biofilm formation still remains the leading cause of conventional antibiotic treatment failure. In contrast to conventional antibiotics nAbts easily penetrate into the biofilm, and selectively target biofilm matrix constituents through the introduction of bacteria specific ligands. In this context, various nanoparticles can be stabilized and functionalized with conventional antibiotics. These composites have a largely enhanced bactericidal efficiency compared to the free antibiotic. Conclusion: Nanoparticle-based carriers deliver antibiotics with better biofilm penetration and lower toxicity, thus combating bacterial resistance. However, the successful adaptation of nanoformulations to clinical practice involves a detailed assessment of their safety profiles and potential immunotoxicity.


2007 ◽  
Vol 52 (2) ◽  
pp. 606-611 ◽  
Author(s):  
Mi-Jung Kim ◽  
Ikuo Hirono ◽  
Ken Kurokawa ◽  
Takeshi Maki ◽  
John Hawke ◽  
...  

ABSTRACT Photobacterium damselae subsp. piscicida is a bacterial fish pathogen that causes a disease known as pasteurellosis. Two transferable multiple-drug resistance (R) plasmids, pP99-018 (carrying resistance to kanamycin, chloramphenicol, tetracycline, and sulfonamide) and pP91278 (carrying resistance to tetracycline, trimethoprim, and sulfonamide), isolated from P. damselae subsp. piscicida strains from Japan (P99-018) and the United States (P91278), respectively, were completely sequenced and analyzed, along with the multiple-drug resistance regions of three other R plasmids also from P. damselae subsp. piscicida strains from Japan. The sequence structures of pP99-018 (150,057 bp) and pP91278 (131,520 bp) were highly conserved, with differences due to variation in the drug resistance and conjugative transfer regions. These plasmids, shown to be closely related to the IncJ element R391 (a conjugative, self-transmitting, integrating element, or constin), were divided into the conjugative transfer, replication, partition, and multiple-drug resistance regions. Each of the five multiple-drug resistance regions sequenced exhibited unique drug resistance marker composition and arrangement.


Author(s):  
Oliver T. Zishiri ◽  
Nelisiwe Mkhize ◽  
Samson Mukaratirwa

Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51%) tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%), trimethoprim-sulfamthoxazole (84%), trimethoprim (78.4%), kanamycin (74%), gentamicin (48%), ampicillin (47%), amoxicillin (31%), chloramphenicol (31%), erythromycin (18%) and streptomycin (12%). All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3")-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in order to mitigate the proliferation of multiple drug resistance across species.Keywords: Salmonella; antimicrobial resistance; chicken; human; susceptibility; virulence gene


2002 ◽  
Vol 46 (2) ◽  
pp. 360-366 ◽  
Author(s):  
Mahmoud. A. Yassien ◽  
Hosam E. Ewis ◽  
Chung-Dar Lu ◽  
Ahmed T. Abdelal

ABSTRACT A genomic library from a strain of Salmonella enterica serovar Paratyphi B that exhibits multiple drug resistance (MDR) was constructed in Escherichia coli. Two of the recombinant plasmids, pNOR5 and pNOR5, conferred resistance only to fluoroquinolones in E. coli, whereas the third, pNCTR4, conferred the MDR phenotype. Sequence and subcloning analysis showed that it is the presence of RecA on the first two plasmids which confers resistance to fluoroquinolones in E. coli. A similar analysis established that the MDR phenotype conferred by pNCTR4 is due to a gene, rma (resistance to multiple antibiotics), which encodes a 13.5-kDa polypeptide. The derived sequence for Rma exhibits a high degree of similarity to those of a group of MarA-like activators that confer MDR in E. coli. A MalE-Rma fusion protein was purified to near homogeneity and was shown to interact with a DNA fragment carrying a MarA operator sequence. Furthermore, overexpression of rma in E. coli caused changes in the outer membrane protein profile that were similar to those reported for MarA. These results suggest that Rma might act as a transcriptional activator of the marA regulon.


2017 ◽  
Vol 33 (S1) ◽  
pp. 52-52
Author(s):  
Xuemei Zhen ◽  
Yuanyuan Li ◽  
Yixi Chen ◽  
Peng Dong ◽  
Stephanie Liu ◽  
...  

INTRODUCTION:Multiple drug resistance (MDR) intra-abdominal infections (IAIs) are associated with noteworthy direct and societal costs. Compared to previous studies, the present one takes both resistance rate and total medical costs (TMCs) into consideration, focusing on the impact of MDR on TMCs in IAIs, as well as further estimating the additional costs at a national level.METHODS:All inpatients discharged between 1 January 2014, and 31 December 2015 from a teaching hospital were included. Due to limits in budget and the large number of inpatients, the randombetween (bottom, top) function was applied to randomly select 40 percent of patients per year. Subsequently, we manually screened out 254 patients with IAIs, according to the International Classification of Disease (tenth revision) and electronic medical records. Eventually, 101 IAIs patients were included, in which 37 were infected by non-MDR bacteria and 64 by MDR bacteria. The Kruskal-wallis non-parametric test and multiple linear regression were employed to analyze the effect of single and multiple variables on TMCs.RESULTS:Compared to patients with non-MDR infections, those with MDR were associated with significantly higher TMCs, higher antimicrobial costs, increased insurance, combination antimicrobial therapy, higher usage of antimicrobial agents, greater number of pathogens, longer length of stay, and longer intensive care unit stays. In addition, the average TMCs among patients with MDR were CNY131,801.17 (1USD was equal to CNY 6.227 in 2015), which were CNY 90,200.99 higher than those with non-MDR infections. If our results are generalizable to the whole country, the total attributable TMCs are estimated to be CNY37.06 billion, and the societal costs of CNY111.18 billion in 2015.CONCLUSIONS:This real-world data analysis demonstrated the significant excessive burden MDR infections are posing to the current Chinese healthcare system in terms of both TMCs and healthcare resource utilization. Enhanced antimicrobial stewardship in China is necessary to curb the distribution of MDR bacteria.


Sign in / Sign up

Export Citation Format

Share Document