scholarly journals Rapid, low-cost fluorescent assay of β-lactamase-derived antibiotic resistance and related antibiotic susceptibility

2014 ◽  
Vol 19 (10) ◽  
pp. 105007 ◽  
Author(s):  
S. Sibel Erdem ◽  
Shazia Khan ◽  
Akilan Palanisami ◽  
Tayyaba Hasan
Author(s):  
Cláudia A. Ribeiro ◽  
Luke A. Rahman ◽  
Louis G. Holmes ◽  
Ayrianna M. Woody ◽  
Calum M. Webster ◽  
...  

AbstractThe spread of multidrug-resistance in Gram-negative bacterial pathogens presents a major clinical challenge, and new approaches are required to combat these organisms. Nitric oxide (NO) is a well-known antimicrobial that is produced by the immune system in response to infection, and numerous studies have demonstrated that NO is a respiratory inhibitor with both bacteriostatic and bactericidal properties. However, given that loss of aerobic respiratory complexes is known to diminish antibiotic efficacy, it was hypothesised that the potent respiratory inhibitor NO would elicit similar effects. Indeed, the current work demonstrates that pre-exposure to NO-releasers elicits a > tenfold increase in IC50 for gentamicin against pathogenic E. coli (i.e. a huge decrease in lethality). It was therefore hypothesised that hyper-sensitivity to NO may have arisen in bacterial pathogens and that this trait could promote the acquisition of antibiotic-resistance mechanisms through enabling cells to persist in the presence of toxic levels of antibiotic. To test this hypothesis, genomics and microbiological approaches were used to screen a collection of E. coli clinical isolates for antibiotic susceptibility and NO tolerance, although the data did not support a correlation between increased carriage of antibiotic resistance genes and NO tolerance. However, the current work has important implications for how antibiotic susceptibility might be measured in future (i.e. ± NO) and underlines the evolutionary advantage for bacterial pathogens to maintain tolerance to toxic levels of NO.


Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 930
Author(s):  
Delia Gambino ◽  
Sonia Sciortino ◽  
Sergio Migliore ◽  
Lucia Galuppo ◽  
Roberto Puleio ◽  
...  

The presence of Salmonella spp. in marine animals is a consequence of contamination from terrestrial sources (human activities and animals). Bacteria present in marine environments, including Salmonella spp., can be antibiotic resistant or harbor resistance genes. In this study, Salmonella spp. detection was performed on 176 marine animals stranded in the Sicilian coasts (south Italy). Antibiotic susceptibility, by disk diffusion method and MIC determination, and antibiotic resistance genes, by molecular methods (PCR) of the Salmonella spp. strains, were evaluated. We isolated Salmonella spp. in three animals, though no pathological signs were detected. Our results showed a low prevalence of Salmonella spp. (1.7%) and a low incidence of phenotypic resistance in three Salmonella spp. strains isolated. Indeed, of the three strains, only Salmonella subsp. enterica serovar Typhimurium from S. coeruleoalba and M. mobular showed phenotypic resistance: the first to ampicillin, tetracycline, and sulphamethoxazole, while the latter only to sulphamethoxazole. However, all strains harbored resistance genes (blaTEM, blaOXA, tet(A), tet(D), tet(E), sulI, and sulII). Although the low prevalence of Salmonella spp. found in this study does not represent a relevant health issue, our data contribute to the collection of information on the spread of ARGs, elements involved in antibiotic resistance, now considered a zoonosis in a One Health approach.


2004 ◽  
Vol 50 (1) ◽  
pp. 185-191 ◽  
Author(s):  
J.E. Ebdon ◽  
J.L. Wallis ◽  
H.D. Taylor

Antibiotic resistance profiling (ARP) is a potentially useful method for distinguishing faecal bacteria according to host source. This phenotypic approach has cost benefits over genotypic methods, but existing protocols are time-consuming and manual data handling is open to human error. A simplified, low-cost approach to the ARP technique was developed that used automated data recording techniques combined with simple statistical analyses to compare isolates of the genus Enterococcus from various faecal sources. An initial battery of 21 antibiotics (at up to four concentrations) was chosen for source discrimination. Images of growth or non-growth in microplate wells were stored as bitmaps and converted to binary data to form a database of known antibiotic resistance profiles. Discriminant function analysis (DFA) showed that the average rate of isolates correctly classified by the database (wastewater vs non-wastewater) was 86%. Once the more discriminating antibiotics and their concentrations had been identified, it was possible to reduce the number of tests from 80 to 18 whilst increasing the number of correctly classified human isolates. ARP could offer a low-cost and rapid means of identifying sources of faecal pollution. As such, the technique may be of particular benefit to developing countries, where water quality may have a significant impact on health and where cost is a major factor when choosing environmental management technology.


2015 ◽  
Vol 78 (1) ◽  
pp. 65-71 ◽  
Author(s):  
MOHD IKHSAN KHALID ◽  
JOHN YEW HUAT TANG ◽  
NABILA HUDA BAHARUDDIN ◽  
NASIHA SHAKINA RAHMAN ◽  
NURUL FAIZZAH RAHIMI ◽  
...  

The present study was conducted to investigate the prevalence and antibiotic resistance among Campylobacter jejuni in ulam at farms and retail outlets located in Kuala Terengganu, Malaysia. A total of 526 samples (ulam, soil, and fertilizer) were investigated for the presence of C. jejuni and the gene for cytolethal distending toxin (cdt) by using a multiplex PCR method. Antibiotic susceptibility to 10 types of antibiotics was determined using the disk diffusion method for 33 C. jejuni isolates. The average prevalence of contaminated samples from farms, wet markets, and supermarkets was 35.29, 52.66, and 69.88%, respectively. The cdt gene was not detected in 24 of the 33 C. jejuni isolates, but 9 isolates harbored cdtC. Antibiotic resistance in C. jejuni isolates was highest to penicillin G (96.97% of isolates) followed by vancomycin (87.88%), ampicillin (75.76%), erythromycin (60.61%), tetracycline (9.09%), amikacin (6.06%), and norfloxacin (3.03%); none of the isolates were resistant to ciprofloxacin, enrofloxacin, and gentamicin. In this study, C. jejuni was present in ulam, and some isolates were highly resistant to some antibiotics but not to quinolones. Thus, appropriate attention and measures are required to prevent C. jejuni contamination on farms and at retail outlets.


Author(s):  
Monzer Hamze ◽  
Marwan Osman ◽  
Hassan Mallat ◽  
Elie Bou Raad

Background. Urinary tract infection (UTI) is common infection feature worldwide.   Infected patients are usually treated empirically treated without culture or antibiotics susceptibility testing, and which may lead to increase antibiotic resistance level. This study aims to determine the prevalence and antibiotic susceptibility patterns of common uropathogenic bacteria isolated at Youssef Hospital Center, Akkar governorate, North of Lebanon. Methods. Spot midstream of urine samples from 9662 patients with UTI symptoms who came for medical investigation to Youssef Hospital Center located in Akkar governorate.  Urine specimens were collected in sterile plastic bottles. Culture, identification and antibiotic susceptibility testing were performed using conventional tools according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing. Results.  A total of 1009 bacterial uropathogens were isolated. Escherichia coli was most presented (72.5%) of all isolates, followed by Klebsiella pneumoniae (8.2%), Enterococcus spp. (5.5%), Pseudomonas aeruginosa (4.5%), Proteus spp. (3%), Enterobacter spp. (2%), Staphylococcus aureus (2%), Streptococcus agalactiae (1.6%), Staphylococcus saprophyticus (0.4%), Acinetobacter baumannii(0.2%) and Providencia rettgeri (0.1%). Moreover, the mean antibiotic resistance rates of isolates was relatively high, but comparable to previously published data in Lebanon. Conclusion. To the best of our knowledge, this is the first investigation reporting epidemiological data regarding the prevalence and antibiotic susceptibility patterns of bacterial uropathogens isolated from patients in the Akkar governorate. Our data indicated the urgent need of a strategic plan to tackle antibiotic resistance, particularly in deprived regions with poor healthcare centers.   Keywords: Uropathogens, Epidemiology, Antibiotic susceptibility, Risk factors, Akkargovernorate, North Lebanon.


2021 ◽  
Vol 23 (3) ◽  
pp. 381-387
Author(s):  
N. M. Polishchuk ◽  
D. L. Kyryk ◽  
I. Ye. Yurchuk

Efficient monitoring of circulating purulent-septic infectious agents in a clinical setting and a study on antibiotic susceptibility of isolated strains of microorganisms allows identifying changes in the pathogen structure and trends in antibiotic resistance development, which helps to determine the tactics of antibacterial therapy and elaborate appropriate measures. The aim of the study. Retrospective analysis of the results of microbiological monitoring of purulent-septic infectious (PSI) agents in the Orthopedics and Traumatology Department (OTD) of the Zaporizhzhia Central Ambulance and Emergency Care Hospital over the period 2017–2020 to determine the main antibacterial drugs for empirical therapy. Materials and methods. We analyzed the bacteriological test results of 664 clinical material samples obtained from OTD patients using bacteriological examination statistical reporting and analytical data of the WHONET 5.6 software. Results. The main PSI pathogens in the OTD were from the ESKAPE group: E. coli, S. aureus, K. pneumoniae, A. baumannii, E. faecalis, P. aeruginosa and S. epidermidis, P. mirabilis, C. amycolatum. Isolates of E. faecalis were sensitive to vancomycin, linezolid, S. aureus – to linezolid, tigecycline, netilmicin, A. baumannii – to tigecycline. All P. aeruginosa strains were resistant to ticarcillin/clavulanate, cefepime, chloramphenicol, imipenem, meropenem, aztreonam, ciprofloxacin. E. coli and K. pneumoniae were resistant to ampicillin, ticarcillin/clavulanate, aztreonam, ceftriaxone, cefepime. The number of isolates sensitive to piperacillin/tazobactam, carbapenems, levofloxacin, gentamicin, amikacin, chloramphenicol ranged from 37 % to 65 %. Conclusions. E. coli, S. aureus, K. pneumoniae, A. baumannii, E. faecalis, P. aeruginosa, S. epidermidis, P. mirabilis, C. amycolatum play an important role in the structure of PSI pathogens in the Orthopedics and Traumatology Department of Zaporizhzhia Central Ambulance and Emergency Care Hospital. The antibiotics of choice as the antibacterial empirical therapy for enterococcal infections are vancomycin, linezolid, for staphylococcal infections – vancomycin, linezolid, tigecycline, netilmicin. PSI pathogens continually evolve developing antibiotic resistance, and it is of particular importance to monitor antibiotic susceptibility of microorganisms within the OTD.


2021 ◽  
Author(s):  
Golnaz Mobasseri ◽  
Thong Kwai Lin ◽  
Cindy Shuan Ju Teh

Abstract Multidrug-resistant (MDR) Klebsiella pneumoniae (K. pneumoniae) poses a serious public health threat. K. pneumoniae strains that produce extended-spectrum beta-lactamases (ESBL) are becoming increasingly reported in nosocomial and community-acquired infections. Besides resistance genes, integrons, and plasmids, altered membrane permeability caused by porin loss and energy-dependent efflux have also contributed to antibiotic resistance in K. pneumoniae. The objective of this study was to determine the correlation between the reduction of antibiotic susceptibility and overexpression of efflux pump as well as the lack of outer membrane proteins (OMPs) among clinical ESBLs resistant K. pneumoniae. The expression levels of ramA, acrA, ompK35 and ompK36 in 12 MDR K. pneumoniae strains with varying MICs levels were analyzed using quantitative real time-Polymerase Chain Reaction (qRT-PCR). The role of efflux pump on antibiotic resistance was also studied by using minimum inhibitory concentration (MICs) method with//without efflux pump inhibitor. The result indicated that the strains with highest resistance to cefotaxime showed the lowest level of ompK35 and ompK36 genes expression while the strains with lowest MIC level of resistance to cefotaxime showed the highest level of expression of acrA and ramA. Our finding also revealed the effect of efflux pump inhibitor phenyl-arginine-b-naphthylamide (PAβN) on the MIC levels of ceftazidime, amoxicillin-clavulanate and cefotaxime which were significantly reduced around 1–7 folds MIC levels. These results suggest that Efflux pump system and deficiently of OMPs contributing role in antibiotic susceptibility which should be taken seriously to prevent the treatment failure due to antimicrobial resistance.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hai-bei Li ◽  
Ai-ming Hou ◽  
Tian-jiao Chen ◽  
Dong Yang ◽  
Zheng-shan Chen ◽  
...  

Given its excellent performance against the pathogens, UV disinfection has been applied broadly in different fields. However, only limited studies have comprehensively investigated the response of bacteria surviving UV irradiation to the environmental antibiotic stress. Here, we investigated the antibiotic susceptibility of Pseudomonas aeruginosa suffering from the UV irradiation. Our results revealed that UV exposure may decrease the susceptibility to tetracycline, ciprofloxacin, and polymyxin B in the survival P. aeruginosa. Mechanistically, UV exposure causes oxidative stress in P. aeruginosa and consequently induces dysregulation of genes contributed to the related antibiotic resistance genes. These results revealed that the insufficient ultraviolet radiation dose may result in the decreased antibiotic susceptibility in the pathogens, thus posing potential threats to the environment and human health.


Author(s):  
Sanjana Mukherjee ◽  
Heather M. Blankenship ◽  
Jose A. Rodrigues ◽  
Rebekah E. Mosci ◽  
James T. Rudrik ◽  
...  

Background: Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that contributes to over 250,000 infections in the US each year. Because antibiotics are not recommended for STEC infections, resistance in STEC has not been widely researched despite an increased likelihood for the transfer of resistance gene from STEC to opportunistic pathogens residing within the same microbial community. Methods: Between 2001 and 2014, 969 STEC isolates were collected from Michigan patients. Serotyping and antibiotic susceptibility profiles to clinically relevant antibiotics were determined using disc diffusion, while epidemiological data was used to identify factors associated with resistance. Whole genome sequencing was used to examine genetic relatedness and identify genetic determinants and mechanisms of resistance in the non-O157 isolates. Results: Increasing frequencies of resistance to at least one antibiotic was observed over the 14 years (p=0.01). While the non-O157 serogroups were more commonly resistant than O157 (Odds Ratio: 2.4; 95% Confidence Interval:1.43-4.05), the frequency of ampicillin resistance among O157 isolates was significantly higher in Michigan compared to the national average (p=0.03). Genomic analysis of 321 non-O157 isolates uncovered 32 distinct antibiotic resistance genes (ARGs). Although mutations in genes encoding resistance to ciprofloxacin and ampicillin were detected in four isolates, most of the horizontally acquired ARGs conferred resistance to aminoglycosides, β-lactams, sulfonamides and/or tetracycline. Conclusions: This study provides insight into the mechanisms of resistance in a large collection of clinical non-O157 STEC isolates and demonstrates that antibiotic resistance among all STEC serogroups has increased over time, prompting the need for enhanced surveillance.


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