Molecular characteristic of rifampin-sensitive and resistant isolates and characteristics of rpoB gene mutations in MRSA

Author(s):  
Yinjuan Guo ◽  
Bingjie Wang ◽  
Lulin Rao ◽  
Xinyi Wang ◽  
Huilin Zhao ◽  
...  

Abstract BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) infections have become a leading cause of bacterial infections in both healthcare and community settings. Mutations in the rpoB gene cause resistance to rifampin (RIF R ), a critical antibiotic for treatment of multidrug-resistant S. aureus . The aim of this study was to detect the molecular characteristics of RIF R MRSA and analysis the rpoB gene mutations involved in RIF resistance. MethodsA total of 49 RIF R MRSA and 38 RIF S MRSA isolates collected from seven cities in China were analyzed by multilocus sequence typing, staphylococcus chromosomal cassette mec (SCC mec ) typing, spa typing, and rpoB gene mutations. ResultsST239-III-t030 (35/49, 71.4%), the major clone in RIF R MRSA isolates; ST45-IV-t116 (16/38, 42.1%), the major clone in RIF S MRSA isolates with rpoB mutations. RIF R MRSA isolates were resistance to erythromycin, ciprofloxacin, tetracycline, gentamicin, and clindamycin. By contrast, RIF S MRSA isolates with rpoB mutation were more susceptible to ciprofloxacin, tetracycline, and gentamicin. Forty-three (87.8%) isolates present the mutational change H481N and L466S, conferring 128-512 μg/ml RIF resistance. The four isolates with RIF MIC > 1024 μg/ml had additional amino acid substitution: H481N, L466S, A473T (n=2); H481Y (n=2), associated with a high-level RIF resistance. Of 38 RIF S MRSA isolates, two mutations were observed, including H481N (n=37) and A477D (n=1). ConclusionThe predominant RIF R MRSA clones in China were ST239III-t030. Molecular character, antibiotic resistant profiles, and rpoB mutations between RIF R MRSA and RIFS MRSA were diverse. Antibiotics for treating patients with MRSA infections can be selected based on molecular characteristics.

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 571
Author(s):  
Nicole Zacharias ◽  
Iris Löckener ◽  
Sarah M. Essert ◽  
Esther Sib ◽  
Gabriele Bierbaum ◽  
...  

Bacterial infections have been treated effectively by antibiotics since the discovery of penicillin in 1928. A worldwide increase in the use of antibiotics led to the emergence of antibiotic resistant strains in almost all bacterial pathogens, which complicates the treatment of infectious diseases. Antibiotic-resistant bacteria play an important role in increasing the risk associated with the usage of surface waters (e.g., irrigation, recreation) and the spread of the resistance genes. Many studies show that important pathogenic antibiotic-resistant bacteria can enter the environment by the discharge of sewage treatment plants and combined sewage overflow events. Mussels have successfully been used as bio-indicators of heavy metals, chemicals and parasites; they may also be efficient bio-indicators for viruses and bacteria. In this study an influence of the discharge of a sewage treatment plant could be shown in regard to the presence of E. coli in higher concentrations in the mussels downstream the treatment plant. Antibiotic-resistant bacteria, resistant against one or two classes of antibiotics and relevance for human health could be detected in the mussels at different sampling sites of the river Rhine. No multidrug-resistant bacteria could be isolated from the mussels, although they were found in samples of the surrounding water body.


2017 ◽  
Vol 63 (11) ◽  
pp. 865-879 ◽  
Author(s):  
Ayman El-Shibiny ◽  
Salma El-Sahhar

Since their discovery in 1915, bacteriophages have been used to treat bacterial infections in animals and humans because of their unique ability to infect their specific bacterial hosts without affecting other bacterial populations. The research carried out in this field throughout the 20th century, largely in Georgia, part of USSR and Poland, led to the establishment of phage therapy protocols. However, the discovery of penicillin and sulfonamide antibiotics in the Western World during the 1930s was a setback in the advancement of phage therapy. The misuse of antibiotics has reduced their efficacy in controlling pathogens and has led to an increase in the number of antibiotic-resistant bacteria. As an alternative to antibiotics, bacteriophages have become a topic of interest with the emergence of multidrug-resistant bacteria, which are a threat to public health. Recent studies have indicated that bacteriophages can be used indirectly to detect pathogenic bacteria or directly as biocontrol agents. Moreover, they can be used to develop new molecules for clinical applications, vaccine production, drug design, and in the nanomedicine field via phage display.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 191 ◽  
Author(s):  
Sobur ◽  
Hasan ◽  
Haque ◽  
Mridul ◽  
Noreddin ◽  
...  

Houseflies (Musca domestica) are well-known mechanical vectors for spreading multidrug-resistant bacteria. Fish sold in open markets are exposed to houseflies. The present study investigated the prevalence and antibiotypes of multidrug-resistant (MDR) Salmonella spp. in houseflies captured from a fish market. Direct interviews with fish vendors and consumers were also performed to draw their perceptions about the role of flies in spreading antibiotic-resistant bacteria. A total of 60 houseflies were captured from a local fish market in Bangladesh. The presence of Salmonella spp. was confirmed using PCR method. Antibiogram was determined by the disk diffusion method, followed by the detection of tetA, tetB, and qnrA resistance genes by PCR. From the interview, it was found that most of the consumers and vendors were not aware of antibiotic resistance, but reported that flies can carry pathogens. Salmonella spp. were identified from the surface of 34 (56.7%) houseflies, of which 31 (91.2%) were found to be MDR. This study revealed 25 antibiotypes among the isolated Salmonella spp. All tested isolates were found to be resistant to tetracycline. tetA and tetB were detected in 100% and 47.1% of the isolates, respectively. Among the 10 isolates phenotypically found resistant to ciprofloxacin, six (60%) were found to be positive for qnrA gene. As far as we know, this is the first study from Bangladesh to report and describe the molecular detection of multidrug-resistant Salmonella spp. in houseflies in a fish market facility. The occurrence of a high level of MDR Salmonella in houseflies in the fish market is of great public health concerns.


Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 688
Author(s):  
Shashi B. Kumar ◽  
Shanvanth R. Arnipalli ◽  
Ouliana Ziouzenkova

Antibiotics have been used as essential therapeutics for nearly 100 years and, increasingly, as a preventive agent in the agricultural and animal industry. Continuous use and misuse of antibiotics have provoked the development of antibiotic resistant bacteria that progressively increased mortality from multidrug-resistant bacterial infections, thereby posing a tremendous threat to public health. The goal of our review is to advance the understanding of mechanisms of dissemination and the development of antibiotic resistance genes in the context of nutrition and related clinical, agricultural, veterinary, and environmental settings. We conclude with an overview of alternative strategies, including probiotics, essential oils, vaccines, and antibodies, as primary or adjunct preventive antimicrobial measures or therapies against multidrug-resistant bacterial infections. The solution for antibiotic resistance will require comprehensive and incessant efforts of policymakers in agriculture along with the development of alternative therapeutics by experts in diverse fields of microbiology, biochemistry, clinical research, genetic, and computational engineering.


2019 ◽  
Author(s):  
Marinelle Rodrigues ◽  
Sara W. McBride ◽  
Karthik Hullahalli ◽  
Kelli L. Palmer ◽  
Breck A. Duerkop

AbstractThe innovation of new therapies to combat multidrug-resistant (MDR) bacteria is being outpaced by the continued rise of MDR bacterial infections. Of particular concern are hospital-acquired infections (HAIs) recalcitrant to antibiotic therapies. The Gram-positive intestinal pathobiontEnterococcus faecalisis associated with HAIs and some strains are MDR. Therefore, novel strategies to controlE. faecalispopulations are needed. We previously characterized anE. faecalisType II CRISPR-Cas system and demonstrated its utility in the sequence-specific removal of antibiotic resistance determinants. Here we present work describing the adaption of this CRISPR-Cas system into a constitutively expressed module encoded on a pheromone-responsive conjugative plasmid that efficiently transfers toE. faecalisfor the selective removal of antibiotic resistance genes. Usingin vitrocompetition assays, we show that these CRISPR-Cas-encoding delivery plasmids, or CRISPR-Cas antimicrobials, can reduce the occurrence of antibiotic resistance in enterococcal populations in a sequence-specific manner. Furthermore, we demonstrate that deployment of CRISPR-Cas antimicrobials in the murine intestine reduces the occurrence of antibiotic-resistantE. faecalisby several orders of magnitude. Finally, we show thatE. faecalisdonor strains harboring CRISPR-Cas antimicrobials are immune to uptake of antibiotic resistance determinantsin vivo. Our results demonstrate that conjugative delivery of CRISPR-Cas antimicrobials may be adaptable for future deployment from probiotic bacteria for exact targeting of defined MDR bacteria or for precision engineering of polymicrobial communities in the mammalian intestine.ImportanceCRISPR-Cas nucleic acid targeting systems hold promise for the amelioration of multidrug-resistant enterococci, yet the utility of such tools in the context of the intestinal environment where enterococci reside is understudied. We describe the development of a CRISPR-Cas antimicrobial, deployed on a conjugative plasmid, for the targeted removal of antibiotic resistance genes from intestinalEnterococcus faecalis. We demonstrate that CRISPR-Cas targeting reduces antibiotic resistance ofE. faecalisby several orders of magnitude in the intestine. Although barriers exist that influence the penetrance of the conjugative CRISPR-Cas antimicrobial among target recipientE. faecaliscells, the removal of antibiotic resistance genes inE. faecalisupon uptake of the CRISPR-Cas antimicrobial is absolute. In addition, cells that obtain the CRISPR-Cas antimicrobial are immunized against the acquisition of new antibiotic resistance genes. This study suggests a potential path toward plasmid based CRISPR-Cas therapies in the intestine.


2017 ◽  
Vol 22 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Kristen Nichols ◽  
Sylvia Stoffella ◽  
Rachel Meyers ◽  
Jennifer Girotto ◽  

The frequent use of antimicrobials in pediatric patients has led to a significant increase in multidrug-resistant bacterial infections among children. Antimicrobial stewardship programs have been created in many hospitals in an effort to curtail and optimize the use of antibiotics. Pediatric-focused programs are necessary because of the differences in antimicrobial need and use among this patient population, unique considerations and dosing, vulnerability for resistance due to a lifetime of antibiotic exposure, and the increased risk of adverse events. This paper serves as a position statement of the Pediatric Pharmacy Advocacy Group (PPAG) who supports the implementation of antimicrobial stewardship programs for all pediatric patients. PPAG also believes that a pediatric pharmacy specialist should be included as part of that program and that services be covered by managed care organizations and government insurance entities. PPAG also recommends that states create legislation similar to that in existence in California and Missouri and that a federal Task Force for Combating Antibiotic-Resistant Bacteria be permanently established. PPAG also supports post-doctoral pharmacy training programs in antibiotic stewardship.


Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1587
Author(s):  
Feng Wang ◽  
Xiaohang Liu ◽  
Zhengyu Deng ◽  
Yao Zhang ◽  
Xinyu Ji ◽  
...  

With the increasing spread of multidrug-resistant bacterial pathogens, it is of great importance to develop alternatives to conventional antibiotics. Here, we report the generation of a chimeric phage lysin, MLTphg, which was assembled by joining the lysins derived from Meiothermus bacteriophage MMP7 and Thermus bacteriophage TSP4 with a flexible linker via chimeolysin engineering. As a potential antimicrobial agent, MLTphg can be obtained by overproduction in Escherichia coli BL21(DE3) cells and the following Ni-affinity chromatography. Finally, we recovered about 40 ± 1.9 mg of MLTphg from 1 L of the host E. coli BL21(DE3) culture. The purified MLTphg showed peak activity against Staphylococcus aureus ATCC6538 between 35 and 40 °C, and maintained approximately 44.5 ± 2.1% activity at room temperature (25 °C). Moreover, as a produced chimera, it exhibited considerably improved bactericidal activity against Staphylococcus aureus (2.9 ± 0.1 log10 reduction was observed upon 40 nM MLTphg treatment at 37 °C for 30 min) and also a group of antibiotic-resistant bacteria compared to its parental lysins, TSPphg and MMPphg. In the current age of growing antibiotic resistance, our results provide an engineering basis for developing phage lysins as novel antimicrobial agents and shed light on bacteriophage-based strategies to tackle bacterial infections.


2019 ◽  
Vol 1 (1) ◽  
pp. 15-22
Author(s):  
John C. Mgogwe ◽  
Hadija H. Semvua ◽  
Oliva Safari ◽  
Gibson E. Kapanda ◽  
Balthazar M. Nyombi ◽  
...  

Background: Molecular identification of mutations resulting in multidrug-resistant tuberculosis (MDR-TB) is an important approach for improving understanding of MDR-TB epidemiology and planning for appropriate interventions. We aimed to estimate the prevalence and distribution of mutations causing MDR-TB as well as determine the gene distribution among patients previously treated for TB. Methods: This was a cross-sectional, hospital-based study conducted from April 2017 to October 2018 at Kibong’oto Infectious Diseases Hospital (KIDH). KIDH is the national MDR-TB referral hospital. Participants were patients presumptively diagnosed with MDR-TB and referred to KIDH from district and regional hospitals across Tanzania. Sputum samples were collected and analysed using the Xpert MTB/RIF assay, direct sputum smear fluorescence microscopy, culture on Lowenstein-Jensen medium, and line probe assay using the GenoType MTBDRplus VER 2.0 system. Demographic information and mutation frequencies were reported as counts and percentages and analysed using descriptive statistics. Results: A total of 208 (69.3%) participants had rpoB gene mutations conferring resistance to only rifampicin; 92 (30.7%) had rpoB, katG, and inhA mutations conferring resistance to rifampicin and isoniazid; 78 (26%) had rpoB and katG mutations conferring resistance to rifampicin and isoniazid; and 14 (4.7%) had rpoB and inhA mutations conferring resistance to rifampicin and isoniazid. Conclusion: The mutation prevalences identified in this study indicate the most frequent mutations were the S531L mutation of the rpoB gene, the S315T1 mutation of the katG gene, and the S315T mutation in the promoter region of the inhA gene. To control the emergence and spread of MDR-TB, drug sensitivity testing must be carried for GeneXpert-confirmed TB patients prior to initiating second-line anti-TB regimens.


2021 ◽  
Vol 15 (10) ◽  
pp. 2506-2511
Author(s):  
Nayyab Sultan ◽  
Sabahat Javaid Butt ◽  
Wajeeha Mehak ◽  
Samreen Qureshi ◽  
Syed Hamza Abbas ◽  
...  

Antibiotics have played a crucial role in the treatment of bacterial infections. Past few decades are marked with advancement of multidrug resistant (MDR) pathogens, which have endangered antibiotic’s therapeutic efficacy. Scientific world is now struggling with the crisis of MDR pathogens. This supreme matter demands careful attention or otherwise it would jeopardize clinical management of infectious diseases. Implication of alternative approaches can pave a new way in the treatment of these troublesome bacteria. Tea leaves are known to pose antibacterial activity against many pathogenic microorganisms. This review has summarized the antibacterial potential of tea leave’s extracts against resistant bacterial pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, Helicobacter pylori, Escherichia coli, Klebsiella pneumonia, Salmonella typhi, Acenitobacter spp, Campylobacter spp. Consumption of natural products such as tea may very well replace, minimize or obliterate this complicated situation. Keywords: Anti-bacterial, Tea, Camellia sinensis, Drug resistant bacteria, Antibiotic resistant bacteria, Synergism, Polyphenols.


2006 ◽  
Vol 50 (8) ◽  
pp. 2860-2862 ◽  
Author(s):  
Emma Huitric ◽  
Jim Werngren ◽  
Pontus Juréen ◽  
Sven Hoffner

ABSTRACT The distribution and resistance levels of 189 in vitro-selected rifampin-resistant Mycobacterium tuberculosis mutants of Beijing and other genotypes were determined. Apart from a higher amount of codon 522 point mutations and large deletions, a spread of mutations similar to that reported for clinical isolates was seen. Most mutations were correlated with high-level resistance; a lower level, or a MIC of <16 mg/liter, was associated with codon 522 mutations. Multiple mutations were detected in two Beijing mutants.


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