scholarly journals Enteric Fever Caused bySalmonella entericaSerovars with Reduced Susceptibility of Fluoroquinolones at a Community Based Teaching Hospital of Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Anjeela Bhetwal ◽  
Anjila Maharjan ◽  
Puspa Raj Khanal ◽  
Narayan Prasad Parajuli
Keyword(s):  
Teaching Hospital ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Isolation And Identification ◽  
Community Based

Enteric fever continues to be an important public health problem especially in developing countries of the tropical region including Nepal. In this study, we aimed to investigate the incidence of enteric fever associated withSalmonella entericaand determine its antimicrobial susceptibilities to therapeutic antimicrobials in a community based teaching hospital of Nepal. A total of 2,304 blood samples from suspected enteric fever patients attending Manmohan Memorial Teaching Hospital were processed with standard microbiological methods for the isolation and identification of bacterial pathogens. TheSalmonella entericaclinical strains were subjected to antimicrobial susceptibility testing by Kirby–Bauer disk diffusion method, and the results were interpreted according to the criteria suggested by the Clinical and Laboratory Standards Institute (CLSI). A total of 245 (10.6%) cases of enteric fever associated withSalmonella entericawere confirmed by blood culture. Out of them, 162 (66.1%) were caused bySalmonellaTyphi and 83 (33.9%) bySalmonellaParatyphi. On Kirby–Bauer disk diffusion antimicrobial susceptibility testing,Salmonellaisolates were highly susceptible to cefixime (100%), ceftriaxone (100%), ampicillin (97.9%), cotrimoxazole (94.6%), azithromycin (96.7%), tetracycline (95.5%), and chloramphenicol (97.5%), respectively. Two hundred twenty-six (92.2%) ofSalmonellaisolates were nalidixic acid resistant with reduced susceptibility to ciprofloxacin (36.7%) and ofloxacin (54.8%), respectively. Although the rate of MDRSalmonellastrains was very low (<5%), their reduced susceptibility to fluoroquinolones has restricted their routine empirical use. Third generation cephalosporins are the safest choice for empirical use but ampicillin, cotrimoxazole, azithromycin, and chloramphenicol can be effective alternatives.

scholarly journals Renaissance of Conventional First-Line Antibiotics inSalmonella entericaClinical Isolates: Assessment of MICs for Therapeutic Antimicrobials in Enteric Fever Cases from Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Puspa Raj Khanal ◽  
Deepa Satyal ◽  
Anjeela Bhetwal ◽  
Anjila Maharjan ◽  
Shreena Shakya ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Blood Samples

Enteric fever caused bySalmonella entericais a life-threatening systemic illness of gastrointestinal tract especially in tropical countries. Antimicrobial therapy is generally indicated but resistance towards commonly used antibiotics has limited their therapeutic usefulness. Therefore, we aimed to determine the antimicrobial susceptibility pattern by minimum inhibitory concentration method of common therapeutic regimens againstSalmonella entericafrom enteric fever clinical cases.Salmonella entericaclinical isolates recovered from the patients with suspected enteric fever whose blood samples were submitted to microbiology laboratory of Manmohan Memorial Community Hospital, Kathmandu, from March 2016 to August 2016, were studied. These isolates were subjected to antimicrobial susceptibility testing against common therapeutic antimicrobials by Kirby-Bauer disk diffusion method. The minimum inhibitory concentration of ciprofloxacin, azithromycin, chloramphenicol, and cefixime was determined by Agar dilution method based on the latest CLSI protocol. A total of 88 isolates ofSalmonella entericawere recovered from blood samples of enteric fever cases. Out of them, 74 (84.09%) wereSalmonellaTyphi and 14 (15.91%) wereSalmonellaParatyphi A. On Kirby-Bauer disk diffusion antimicrobial susceptibility testing, entire isolates were susceptible to cotrimoxazole, cefixime, ceftriaxone, azithromycin, and chloramphenicol. Sixty-four (72.7%)Salmonella entericaisolates were nalidixic acid resistant and nonsusceptible to ciprofloxacin and levofloxacin. On MIC determination, fourSalmonellaisolates were ciprofloxacin resistant with MIC 1 µg/ml and two isolates were ciprofloxacin intermediate with MIC 0.5 µg/ml. The MIC range of azithromycin was from 0.125 µg/ml to 2.0 µg/ml, whereas that for chloramphenicol was 2.0 µg/ml–8.0 µg/ml and for cefixime was 0.0075–0.5 µg/ml, respectively. Despite global surge of antimicrobial resistance amongSalmonella entericaclinical isolates, the level of drug resistance in our study was not so high. However, higher level of NARST strains limits therapeutic use of fluoroquinolones and necessitates the routine monitoring of such resistance determinants in order to effectively and rationally manage enteric fever cases.

scholarly journals Performance Evaluation of BD Phoenix NMIC-413 Antimicrobial Susceptibility Testing Panel for Imipenem, Meropenem, and Ertapenem Against Clinical Carbapenem-Resistant and Carbapenem-Susceptible Enterobacterales

2021 ◽  
Vol 8 ◽  
Author(s):  
Jingjia Zhang ◽  
Peiyao Jia ◽  
Ying Zhu ◽  
Ge Zhang ◽  
Yingchun Xu ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Screening Methods ◽  
Major Error ◽  
Disk Diffusion Method ◽  
Suitable Alternative ◽  
Carbapenem Resistant

Purpose: The infection of carbapenem-resistant Enterobacterales (CRE) has become a major clinical and healthcare problem worldwide. The screening methods of CRE have been extensively developed but still need improving [e.g., tests with accurate and simple minimum inhibitory (MICs)]. In this study, the performance of the BD Phoenix NMIC-413 AST panel was evaluated against clinical CRE and carbapenem-susceptible Enterobacterales (CSE) in China. The panel was first evaluated in the Chinese clinical lab.Methods: Antimicrobial susceptibility testing of 303 clinical Enterobacterales isolates were conducted by broth microdilution (BMD), Phoenix NMIC-413 AST panel, and disk diffusion method for imipenem, ertapenem, and meropenem. Considering BMD is a gold standard, essential agreement (EA), categorical agreement (CA), minor error (MIE), major error (ME), and very major error (VME) were determined according to CLSI guidelines. CA and EA &gt; 90%, ME &lt;3%, and VME &lt;1.5% were considered as acceptable criteria. Polymerase chain reaction and sanger sequencing were performed to determine the β-lactamase genotypes of CRE isolates.Results: Three hundred and three isolates included 195 CREs and 108 CSEs were enrolled according to the BMD-MIC values of three carbapenems. Tested CREs showing 100 blaKPC−2-positive organisms, 31 blaIMP-positive organisms, 28 blaNDM-positive organisms, 5 blaVIM-positive organisms, 2 both blaIMP and blaVIM-positive organisms, 2 blaOXA−48-positive organisms, and 27 isolates without carbapenemase genes. For the Phoenix NMIC-413 method, CA and EA rates &gt;93%, MIE rates &lt;5%, ME rates &lt;1.75%, and VME rates were 0%, across the three drugs. For the disk diffusion method, the CA rates for three drugs were all &gt;93%, while the MIE and ME rates were all &lt;5 and &lt;3%, respectively. VME rate was 3.28% for imipenem, exceeded the cut-off value specified by CLSI M52, 0 and 0.56% for ertapenem and meropenem, separately.Conclusion: Based on the genomic data, the detection of CRE and CSE was more reliable using the BD Phoenix NMIC-413 panel compared to the BMD and disk approaches. Therefore, our study supports the use of BD Phoenix NMIC-413 panel as a suitable alternative to BMD for the detection of carbapenem resistant isolates in a clinical setting.

Method Preferences and Test Accuracy of Antimicrobial Susceptibility Testing

2001 ◽  
Vol 125 (10) ◽  
pp. 1285-1289 ◽  
Author(s):  
Ronald N. Jones
Keyword(s):  
Quality Control ◽  
Minimal Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Quantitative Accuracy ◽  
Concentration Methods

Abstract Objective.—To summarize the antimicrobial susceptibility testing results from the College of American Pathologists (CAP) Microbiology Surveys Program for 2000. Specifically, the frequency of tests used and the quantitative and qualitative (susceptibility category) accuracy were assessed. Design.—The CAP Microbiology Surveys challenged subscribers in 2000 with 3 well-characterized organisms for antimicrobial susceptibility testing in pure culture. Each laboratory was to use the test method and reporting procedures routinely applied to patient samples. The strains were National Committee for Clinical Laboratory Standards (NCCLS) quality control organisms with precisely defined antimicrobial susceptibility patterns and reproducibility. Results reported by participants (2685–2979/sample) were graded for categorical accuracy and quantitative performance by comparing reported minimal inhibitory concentrations (μg/mL) or zone diameters (mm) against quality control ranges published by the NCCLS. The appropriateness of reported drugs was determined in the context of the type and anatomic location of the infection. Results.—The tests most often used varied by the species of the organism and growth characteristics of the isolated strains. Nonfastidious, rapid-growing Surveys unknowns (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) were most often tested with commercial systems (MicroScan, 42.0%–42.4%; Vitek, 41.5%–43.0%) or with the standardized disk diffusion method (12.8%–13.9%). In contrast, fastidious species, such as Streptococcus pneumoniae (ATCC 49619), were predominantly tested by Etest (40.3%), followed by disk diffusion (27.6%) and MicroScan (23.2%). Categorical accuracy was essentially equal between dilution (98.9%) and diffusion (99.0%) methods. Among the minimal inhibitory concentration methods used to test penicillin against S pneumoniae, Etest method quantitative accuracy (96.3%) was greater than that of MicroScan (92.4%). Quantitative accuracy was greatest for dilution minimal inhibitory concentration methods, with more than 90% of results within NCCLS quality control ranges for nearly all reported antimicrobials. Reevaluations of quality control ranges may be needed for 4 to 7 agents, depending on method. Reporting errors were also detected in 2 areas: (1) reporting results for drugs not active at the site of infection and (2) reporting results for drugs tested with suboptimal methods without published NCCLS interpretive criteria. Conclusions.—Antimicrobial susceptibility testing methods used in US laboratories were dominated by commercial products with relatively high accuracy (qualitative and quantitative). As available methods have become better suited to both fastidious and rapid-growing species, reporting errors have assumed a higher level of concern to the CAP Surveys in an effort to minimize prescription errors.

scholarly journals A survey of methods used for antimicrobial susceptibility testing in veterinary diagnostic laboratories in the United States

2017 ◽  
Vol 29 (5) ◽  
pp. 669-675 ◽  
Author(s):  
David A. Dargatz ◽  
Matthew M. Erdman ◽  
Beth Harris
Keyword(s):  
United States ◽  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
The United States ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution

Antimicrobial resistance is a serious threat to animal and human health worldwide, requiring a collaborative, holistic approach. The U.S. Government has developed a national strategy to address antimicrobial resistance, with one component being to monitor antimicrobial resistance in agricultural settings. We developed a survey to collect information about antimicrobial susceptibility testing (AST) from the veterinary diagnostic laboratory community in the United States, assessing current practices and technologies and determining how AST information is shared. Of the 132 surveys administered, 52 (39%) were returned. Overall, responding laboratories conducted susceptibility tests on 98,788 bacterial isolates in 2014, with Escherichia coli being the most common pathogen tested across all animal species. The 2 most common AST methods employed were the disk diffusion method (71%) and the Sensititre platform broth microdilution system (59%). Laboratories primarily used the Clinical Laboratory Standards Institute (CLSI) VET-01 standard (69%) and the automatically calculated interpretations provided by the commercial AST systems (61%) for interpreting their AST data. Only 22% of laboratories published AST data on a periodic basis, usually via annual reports published on the laboratory’s website or through peer-reviewed journals for specific pathogens. Our results confirm that disk diffusion and broth microdilution remain the standard AST methods employed by U.S. veterinary diagnostic laboratories, and that CLSI standards are commonly used for interpreting AST results. This information will help determine the most efficient standardized methodology for future surveillance. Furthermore, the current infrastructure within laboratories, once harmonized, will help provide a mechanism for conducting national surveillance programs.

scholarly journals Contamination and Antimicrobial Susceptibility Testing of Staphylococcus aureus Isolated from Pork in Fresh Markets, Nongchok District, Thailand

2021 ◽  
Vol 2021 ◽  
pp. 1-3
Author(s):  
Doungjit Kanungpean ◽  
Shinji Takai ◽  
Tsutomu Kakuda
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Severe Infection ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Meat Markets ◽  
Pork Samples

We surveyed Staphylococcus aureus contamination in 110 pork samples from 12 fresh meat markets in Nongchok district, Bangkok, Thailand, and performed antimicrobial susceptibility testing with the disk diffusion method. The prevalence of S. aureus was 28.18%, and 52 strains were isolated. Antimicrobial susceptibility testing using the disk diffusion method revealed that 80.77% of the isolates were resistant to tetracycline and 76.92% to ampicillin. All strains were 100% susceptible to cloxacillin, cefoxitin, gentamicin, and cefazolin. The high percentage of antibiotic resistance to tetracycline and ampicillin was attributed to their use in treating infections in farmed animals and their addition to animal food for disease prevention. Interestingly, the present study revealed the intermediate resistance of S. aureus (13.46% of S. aureus-positive pork samples) to vancomycin which is a common medicine for treating severe infection in humans, suggesting that the trend of resistance might increase and becoming a serious problem of public health for both humans and animals.

scholarly journals Antimicrobial susceptibility pattern of Salmonella enterica, blood-stream isolates, among febrile children: a prospective study from Nepal

2019 ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Shovana Thapa
Keyword(s):  
Nalidixic Acid ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Susceptibility Pattern ◽  
First Line ◽  
Disk Diffusion Test ◽  
Antimicrobial Susceptibility Pattern

Abstract Background Still, in developing the children are being treated empirically and irrationally with accessible antibiotic without susceptibility testing and minimal lethal dose calculations, defying the probable MDR (multi-drug resistance) isolates. This study was undertaken in the febrile children to determine the antimicrobial susceptibility pattern of Salmonella enterica against commonly prescribed antibiotics. Method All isolates were identified by biotyping and serotyping standard protocols then tested against antibiotics by modified Kirby disk-diffusion method. Minimum Inhibitory Concentration (MIC) of isolates were determined by agar dilution method and compared with disk diffusion results and on nalidixic-acid sensitive/resistant strains. Result Among 1815 enteric-fever-suspects, 90(4.9%) isolates of Salmonella enterica [serovar: 62(68.8%) Salmonella Typhi and 28 (31.1%) Salmonella Paratyphi A] were recovered. The incidence of infection was higher among male, age group 5 to 9, and patient from the out-patient department (OPD). On disk-diffusion test most isolates, were sensitive against first-line drugs, cephalosporins, and macrolides. However, against quinolone, a huge percentile i.e. 93.3%, of isolates were resistant [including 58 Typhi and 26 Paratyphi serovar], and nearly 14% against fluoroquinolones. When MIC breakpoint was adjusted 4µg/ml for azithromycin, ≥1 µg/ml for ciprofloxacin, 2µg/ml for ofloxacin, 8µg/ml for nalidixic acid, 1µg/ml for cefixime, higher sensitivity and specificity achieved while screening decreased susceptibility. Among tested antibiotics, low rate of resistant strain observed on MIC of azithromycin. Also, higher resistance against fluoroquinolones observed on NARS strain. Conclusion Higher susceptibility of Salmonella enterica to first-line drugs (the conventional antityphoidal drugs), third-generation cephalosporins, and azithromycin; advocates for its reconsideration in the implicated therapy. However, lower susceptibility against fluoroquinolones among nalidixic-acid resistant Salmonella (NARS) strain negates its empirical use in children. Keywords Enteric fever, Nepal, children, Salmonella enterica

ANTIMICROBIAL SUSCEPTIBILITY IN CULTURE POSITIVE ENTERIC FEVER

2019 ◽  
Vol 3 (7) ◽  
Author(s):  
Dr. Manish Kulshrestha ◽  
Dr. Anjali Kulshrestha
Keyword(s):  
Bone Marrow ◽  
Blood Culture ◽  
Nalidixic Acid ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Multidrug Resistant ◽  
Bone Marrow Culture ◽  
Diffusion Method ◽  
Culture Positive

INTRODUCTION: Enteric fever includes typhoid and paratyphoid fever. Peak incidence is seen in children 5–15 years of age; but in regions where the disease is highly endemic, as in India, children younger than 5 years of age may have the highest infection rates. There are about 22 million new typhoid cases occur each year. Young children in poor, resource limited areas, who make up the majority of the new cases and there is a mortality figures of 215,000 deaths annually. A sharp decline in the rates of complications and mortality due to typhoid fever is observed as a result of introduction of effective antibiotic therapy since 1950s. MDR-ST became endemic in many areas of Asia, including India soon after multidrug-resistant strains of Salmonella enterica serotype typhi (MDR-ST) that were resistant to all the three first-line drugs then in use, namely chloramphenicol, amoxycillin and co-trimoxazole emerged in early 1990s. MATERIAL AND METHODS: Only blood culture or bone marrow culture positive cases were included. The patients with culture isolated enteric fever were included in the study. Antimicrobial susceptibility testing was carried out by disk diffusion method using antibiotic discs. The analysis of the antimicrobial susceptibility was carried out as per CLSI interpretative guidelines. RESULTS: A total of 82 culture positive cases were included in the present study. 80 culture isolates were from blood culture and 2 from the bone marrow culture. Salmonella entericasubspecies enterica serovartyphi (S typhi) was isolated from 67 (81.70%) patients while Salmonella enterica subspecies entericaserovarparatyphi (S paratyphi A) was isolated from 13 (15.85%) cases and 2 (2.44%) were Salmonella enterica subspecies entericaserovarschottmuelleri (S paratyphi B). Of the 82 cases 65(79.3%) isolates were resistant to ciprofloxacin, 17 (20.7%) were resistant to nalidixic acid, one (1.2%) case each was resistant to Cefotaxime and ceftriaxone, 2 (2.4%) were resistant to chloramphenicol, 10 (12.2%) were resistant and to cotrimoxazole 3 (3.7%) were resistant. CONCLUSION: In a culture positive cases 65(79.3%) isolates were resistant to ciprofloxacin and 17 (20.7%) were resistant to nalidixic acid. Multidrug resistant isolates were 65(79.3%).

scholarly journals Specific and rapid reverse assaying protocol for detection and antimicrobial susceptibility testing of Pseudomonas aeruginosa based on dual molecular recognition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong He ◽  
Hang Zhao ◽  
Yuanwen Liu ◽  
He Zhou
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Susceptibility ◽  
Magnetic Particles ◽  
Susceptibility Testing ◽  
Fluorescein Isothiocyanate ◽  
High Specificity ◽  
Antimicrobial Susceptibility Testing ◽  
Tail Fiber ◽  
Isolation And Identification ◽  
Magainin Ii

AbstractThe worldwide emergence and spread of antimicrobial resistance is accelerated by irrational administration and use of empiric antibiotics. A key point to the crisis is a lack of rapid diagnostic protocols for antimicrobial susceptibility testing (AST), which is crucial for a timely and rational antibiotic prescription. Here, a recombinant bacteriophage tail fiber protein (TFP) was functionalized on magnetic particles to specifically capture Pseudomonas aeruginosa, while fluorescein isothiocyanate-labeled-magainin II was utilized as the indicator. For solving the magnetic particles’ blocking effects, a reverse assaying protocol based on TFP recognition was developed to investigate the feasibility of detection and AST of P. aeruginosa. P. aeruginosa can be rapidly, sensitively and specifically detected within 1.5 h with a linear range of 1.0 × 102 to 1.0 × 106 colony forming units (CFU)⋅mL−1 and a detection limit of 3.3 × 10 CFU⋅mL−1. Subsequently, AST results, which were consistent with broth dilution results, can be obtained within 3.5 h. Due to the high specificity of the TFP, AST can actually be conducted without the need for bacterial isolation and identification. Based on the proof-of-principle work, the detection and AST of other pathogens can be extended by expressing the TFPs of their bacteriophages.

scholarly journals Development of an In-House Rapid Antimicrobial Susceptibility Testing Protocol for Positive Blood Culture and Its Implementation in Routine Microbiology Laboratories

2021 ◽  
Vol 12 ◽  
Author(s):  
Min Cao ◽  
Lin Huang ◽  
Yanyan Hu ◽  
Yinfei Fang ◽  
Rong Zhang ◽  
...  
Keyword(s):  
Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Total Error ◽  
Agar Plate ◽  
Error Rates ◽  
Antimicrobial Susceptibility Testing ◽  
Diffusion Method ◽  
High Morbidity ◽  
Clinical Strains

Bloodstream infections (BSI) are associated with high morbidity and mortality and remain a leading cause of death. Blood culture (BC) including the identification and the antimicrobial susceptibility testing of the causative microorganisms should be performed as soon as possible. In this study, we developed an in-house rapid antimicrobial susceptibility testing (rAST) protocol for positive BC. First, the rAST was performed in the simulated positive BC of standard strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and Pseudomonas aeruginosa ATCC 27853) at three different times to assess the reproducibility and operability by dispensing four drops of BC broth onto a Mueller–Hinton agar plate after a positive signal. Furthermore, the rAST was performed in clinical positive BCs. The results of rAST at 4, 6, 8, and 18 h of incubation were compared with results of the standard 16- to 20-h disk diffusion method, and the preliminary breakpoints of the rAST method were established according to the inhibition diameter of sensitive strains and resistant strains. Finally, the rAST was performed in the simulated positive BC of clinical strains to evaluate the availability of the preliminary breakpoints. The rAST results of standard strains were distributed evenly at three different times. Among the 202 clinical strains used to establish the preliminary breakpoints, the number of zone diameters that could be read and interpreted (60, 87, 98, and 100%) increased with incubation time (4, 6, 8, and 18 h), and the categorical agreement was acceptable, with total error rates of 3.0, 2.3, 2.1, and 1.3% at 4, 6, 8, and 18 h of incubation, respectively. In conclusion, the in-house rAST protocol for positive BC can be implemented in routine laboratories. It provides reliable antimicrobial susceptibility testing results for BSI pathogens after 4–6 h of incubation.

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