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Antibiotic resistance is a serious threat that occurs globally in the health sector due to increased consumption of inappropriate antibiotics. Guidelines for prescribing antibiotics for ARTIs have been issued in general practice to promote rational antibiotic prescribing. This study was conducted to compare the effectiveness of cefixime and tetracycline as a solution to improve monitoring of appropriate antibiotic use in the treatment of ARTIs. All stock isolates were rejuvenated first, and cultured on standard media and Kirby–Bauer disc diffusion method was used for susceptibility testing in accordance with the Clinical and Laboratory Standard Institute’s (CLSI) recommendations. Identification of bacteria from a single isolate was carried out to determine which bacteria were resistant to cefixime and tetracycline. A total of 466 single isolates of bacteria were analyzed, which showed a percentage of resistance to cefixime 38.0%, and tetracycline 92.86%. Bacterial isolates were resistant to cefixime and tetracycilne was a genus of Haemophilus, Streptococcus, Corynebacterium, Staphylococcus, and bordetella. Cefixime compared to tetracycline was proven to be superior in terms of the effectiveness of ARIs treatment.

Background: Considering the interesting role in the peptidoglycan biosynthesis pathway, the enzyme UDP-N-acetylglucosamine enolpyruvyl transferase is an attractive target to develop new antibacterial agents. It catalyzes the first key step of this pathway and its inhibition leads to bacterial cell death. Fosfomycin is known as the natural inhibitor of MurA. Objective: The study aimed to introduce new inhibitors of MurA by virtual screening of different chemical compounds libraries, and test the best scored “virtual hits” against three pathogenic bacteria: Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Methods: A virtual screening of the structural analogues of fosfomycin downloaded from the Pub- Chem database was performed. Moreover, French National Chemical Library and ZINC database were also utilized to identify new structures different from fosfomycin. FlexX was the software used for this study. The antibacterial testing was divided into two methods: disk diffusion and broth dilution. Results: A set of virtual hits was found to have better energy score than that of fosfomycin, seven of them were tested in vitro. In addition, the disk diffusion method explored four compounds that exhibited antibacterial activity: CID-21680357 (fosfomycin analogue), AB-00005001, ZINC04658565, and ZINC901335. The testing was continued by broth dilution method for both compounds CID-21680357 and ZINC901335 to determine their minimum inhibitory concentrations, and ZINC901335 had the best value with 457μg/ml against Staphylococcus aureus. Conclusion: Four compounds were found and proven in silico and in vitro to have antibacterial activity: CID-21680357, AB-00005001, ZINC04658565, and ZINC901335.

Background/Purpose The aim of this study was to characterize the S. aureus strains isolated from periodontal lesions of patients, to determine the expression of genes involved in cell adhesion upon their infection of human epithelial cells using an in vitro model, its biofilm formation, and its resistance to antibiotics. Methods S. aureus was analysed by PCR, Kirby-Bauer, and pulsed-field gel electrophoresis (PFGE), measuring gene expression by real-time PCR after infection of human cells in vitro . Results S. aureus was identified in 18.6% (50/268) of the samples. All strains (n = 50) possessed the virulence genes spa ( Staphylococcal protein A) , coa (coagulase), and icaAB (intercellular adhesin); 96% (n = 48) possessed clfB (clumping factor B), and 88% (n = 44) possessed ebps (elastin-binding protein) and sdrD (serine aspartate repeat protein D). All strains were resistant to methicillin, ampicillin, dicloxacillin, cefotaxime, and penicillin, and were multidrug resistant to 6–12 antibiotics. PFGE analysis showed 37 different pulsed-field types and most strains (60.4%) had a unique pulsed-field type. Twenty-four distinct combinations of virulence genes and antibiotic-resistant phenotypes were identified. Conclusion Although S. aureus has been considered a transient member of the oral microbiota, our results indicate a high-level expression of virulence genes and multidrug resistance in the strains isolated from periodontal lesions. These strains might complicate the successful treatment of the disease.

Objective Fibrin sealants have been used for hemostasis, sealant for cerebrospinal fluid leakage, and adhesive barrier in neurosurgery. Further, as its clinical use and role of an effective drug delivery vehicle have been proposed. This study was performed to measure antibacterial activity and continuous local antibiotic release from different concentrations of vancomycin-impregnated fibrin sealant in vitro. Methods Antibacterial activity was investigated by disk diffusion test by measuring the diameter of the growth inhibition zone of bacteria (methicillin-resistant Staphylococcus aureus, ATCC29213) from vancomycin-embedded fibrin sealant disc diluted at five different concentrations (C1-C5; 8.33, 4.167, 0.83, 0.083, and 0.0083 mg/disc, respectively). Continuous and conditioned release of vancomycin concentration (for 2 weeks and for 5 days, respectively) were also measured using high-performance liquid chromatography (HPLC) method. To mimic the physiologic wound conditions with in vitro, conditioned vancomycin release in phosphate buffer solution (PBS) was measured and replaced PBS for five consecutive days, half a day or completely daily. Results In the disk diffusion test, the mean diameters of bacterial inhibition zone were 2.54±0.07 cm, 2.61±0.12 cm, and 2.13±0.15 cm (C1, C2, and C3 respectively) but 1.67±0.06 cm and 1.23±0.15 cm in C4 and C5, respectively. Continuous elution test elicited the peak release of vancomycin from the fibrin sealant at 48 hours, with continued release until 2 weeks. However, conditioned vancomycin release decreased to half or more on day 2, however, the sustainable release was measured over the therapeutic dose (10-20 μg/mL) for 5 days and 4 days in assays of half and total exchange of PBS. Conclusion This study suggests that fibrin sealant can provide an efficient vehicle for antibiotic drug release in a wide range of neurosurgical procedures and the safe and effective therapeutic dose will be at the concentration embedded of 4.167 mg/disc or more of vancomycin.

Introduction: The dramatic increase in the prevalence and clinical impact of infections caused by Carbapenemase-Producing Bacteria in the nosocomial setting in Latin America represents an emerging challenge to public health. The present study detected carbapenemase-producing Gram-negative bacteria in patients from a Hospital from Venezuela, by phenotypic and genotypic methods. Methodology: The bacterial identification was carried out using conventional methods. The resistance to carbapenems was performed by Kirby-Baüer disk diffusion method, according to CLSI recommendations. The modified Hodge Test, double-disk with phenylboronic acid, double-disk with EDTA and Blue Carba Test were performed to detect phenotypic carbapenemase producers. The carbapenemase-encoding genes blaKPC, blaVIM, blaIMP, blaOXA-2, blaOXA-3, blaOXA-15 and blaOXA-21 were determined. Results: The bacterial species identified were Klebsiella pneumoniae complex (181), Pseudomonas aeruginosa (51), and Acinetobacter baumannii-calcoaceticus complex (119). KPC-type was detected in 40.17% of isolates and VIM-type in 14.53%. KPC-type gene was only identified in K. pneumoniae isolates (77.9%). VIM-type gene was identified in P. aeruginosa (86.27%) and K. pneumoniae isolates (3.87%). There was not detection of IMP-type and OXA-type genes. Conclusions: We found a predominance of K. pneumoniae KPC producers and a high rate of VIM-producing P. aeruginosa. The epidemiology of CPB in Venezuela is rapidly evolving, and enhanced surveillance and reporting are needed across the healthcare continuum.

BACKGROUND AND OBJECTIVE Commiphora gileadensis is a plant in the Burseraceae family that grows in the western area of Saudi Arabia. Traditionally, it is used in the treatment of some superficial infections. MATERIALS AND METHODS The methanolic extract of Commiphora gileadensis isolated from its leaves and branches. The in vitro study was conducted to determine the effect of this extract on Methicillin-Resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa using an agar diffusion and Minimum inhibitory concentration (MIC) methods. The in vivo study was conducted through two different methods. The first method, 20 male Balb c-1 mice were used for the determination of Commiphora gileadensis methanolic extract toxicity (LD50). In the second method, 40 male mice were used and were put into four groups. The first and second groups were injected subcutaneously with 108 CFU of MRSA 1 mL-1, while the third and fourth groups were injected with 108 CFU of Pseudomonas aeruginosa 1 mL-1. The comparison between groups was done by using a t-test (p

Contamination of ready-to-eat (RTE) foods by pathogenic bacteria may predispose consumers to foodborne diseases. This study investigated the presence of bacterial contaminants and their antibiotic susceptibility patterns in three locally processed RTE foods (eko, fufu and zobo) vended in urban markets in Ogun state, Nigeria. Bacteria isolated from a total of 120 RTE food samples were identified by 16S rRNA gene phylogeny while susceptibility patterns to eight classes of antibiotics were determined by the disc diffusion method. Species belonging to the genera Acinetobacter and Enterobacter were recovered from all RTE food types investigated, Klebsiella and Staphylococcus were recovered from eko and fufu samples, while those of Shigella were recovered from eko samples. Enterobacter hormaechei was the most prevalent species in all three RTE food types. Precisely 99% of 149 isolates were multidrug-resistant, suggesting a high risk for RTE food handlers and consumers. Co-resistance to ampicillin and cephalothin was the most frequently observed resistance phenotype. Results demonstrate that improved hygiene practices by food processors and vendors are urgently required during RTE processing and retail. Also, adequate food safety guidelines, regulation and enforcement by relevant government agencies are needed to improve the safety of RTE foods and ensure the protection of consumer health.

Objectives The aim of this study was to evaluate antibiotic susceptibility patterns in commercially available dietary and probiotic supplements. Methods Probiotic strains were isolated from the dietary supplements (designated as sample B, D and V), and multidrug resistance profiles were tested using the Kirby-Bauer test. Minimum inhibitory concentrations and double-disk synergy tests were performed to detect the mechanism of action of the resistance, and the presence of extended spectrum β-lactamase activity (ESBL) was confirmed. Results The isolates Streptococcus faecalis and Bacillus mesentericus (both from sample B) were found to be resistant to penicillin G, Lactobacillus acidophilus (sample D) was resistant to ampicillin, and all the isolates from samples B, D and V were resistant to ceftazidime. The isolates Lactobacillus sporogenes, S. faecalis, B. mesentericus from sample B, Lactobacillus. rhamnosus, Saccharomyces boulardii from sample D, and L. sporogenes (sample V) were resistant to erythromycin. Conclusions The findings showed the presence of antibiotic resistance in probiotic bacteria isolated from commercially available dietary supplements. Because multidrug resistance is a serious emerging issue, and the risk of drug-resistant gene transfer to commensals or pathogens of the gut is inevitable, the safety of probiotics has become a major criterion of interest. The findings of this study would serve as a platform for further screening and characterization of the determinants of antibiotic resistance and the genetic mechanisms of resistance.

Bacterial soft rot caused by the bacteriaDickeyaandPectobacteriumis a destructive disease of vegetables, as well as ornamental plants. Several management options exist to help control these pathogens. Because of the limited success of these approaches, there is a need for the development of alternative methods to reduce losses. In this study, we evaluated the effect of potassium tetraborate tetrahydrate (PTB) on the growth of sixDickeyaandPectobacteriumspp. Disc diffusion assays showed thatDickeyaspp. andPectobacteriumspp. differ in their sensitivity to PTB. Spontaneous PTB-resistant mutants ofPectobacteriumwere identified and further investigation of the mechanism of PTB resistance was conducted by full genome sequencing. Point mutations in genescpdBandsupKwere found in a singlePectobacterium atrosepticumPTB-resistant mutant. Additionally, point mutations in genesprfB(synonymsupK) andprmCwere found in two independentPectobacterium brasiliensePTB-resistant mutants.prfBandprmCencode peptide chain release factor 2 and its methyltransferase, respectively. We propose the disruption of translation activity due to PTB leads toPectobacteriumgrowth inhibition. TheP. atrosepticumPTB-resistant mutant showed altered swimming motility. Disease severity was reduced forP. atrosepticum-inoculated potato stems sprayed with PTB. We discuss the potential risk of selecting for bacterial resistance to this chemical.

Aim: A sodium alginate-based biohydrogel was prepared integrating choline oleate deep euthetic solvent as facilitator of transdermal delivery and a cocktail of lytic bacteriophages for Acinetobacter baumannii, aiming at treating soft-tissue infections by the aforementioned pathogen. Materials & methods: Two bacteriophages were isolated from a hospital sewage and a wastewater treatment plant sewage in Sorocaba (Brazil), and characterized via SDS-PAGE electrophoresis, transmission electron microscope and evaluation of lytic spectra of the bacteriophage cocktail. The biohydrogel was prepared and characterized by DSC, FTIR, XRD, DESEM, XRT and transdermal permeation of the bacteriophage cocktail. Results & conclusion: The physico-chemical characterization of the biohydrogel produce indicated adequate structural characteristics and ability to promote/facilitate transdermal delivery of bacteriophage particles, thus showing potential for biopharmaceutical applications.

Background Colistin has become a last-resort antibiotic for the management of multidrug-resistant gram-negative bacteria. The disk diffusion test is cheap and easy to perform but may be unreliable for colistin susceptibility testing due to poor diffusion of the large colistin molecule. An improved agar diffusion test would increase the reliability of colistin susceptibility testing. This study aimed to modify Muller-Hinton agar (MHA) to improve colistin diffusion in agar. Methods MHA was modified by reducing the agar concentration from 100% to 30% and supplementing with protamine. We tested 60 gram-negative clinical isolates of Pseudomonas aeruginosa (N=27) and Acinetobacter calcoaceticus-baumannii complex (N=33). Disk diffusion test results were interpreted based on minimum inhibitory concentrations determined by broth microdilution. Results The modified MHA yielded the best performance metrics, including 94.7% sensitivity, 100% specificity, and an area under the curve of 0.995 (95% confidence interval, 0.982–1.000), P

Resumen Introducción. La aparición de enterobacterias multirresistentes y productoras de betalactamasas de espectro extendido en pacientes ambulatorios con infecciones urinarias representa un problema de salud pública en Perú. Objetivo. Comparar los perfiles de resistencia de Escherichia coli uropatógenas e identificar los fenotipos de cepas productoras de betalactamasas de espectro extendido en tres establecimientos privados de salud localizados en las regiones de la costa, la sierra y la selva de Perú. Materiales y métodos. Se llevó a cabo durante el 2016 un estudio descriptivo de 98 muestras de orina de pacientes con infección urinaria, 35 procedentes de Lima (costa), 38 de Juliaca (sierra) y 25 de Iquitos (selva), en el que se determinó la sensibilidad antimicrobiana utilizando ocho discos antibióticos. Asimismo, se evaluó la producción de betalactamasas de espectro extendido con discos de cefotaxima, de ceftazidima o de su combinación, con ácido clavulánico en agar Mueller-Hinton. Resultados. Se identificaron 18 perfiles de resistencia que incluían desde los sensibles a todos los antibióticos hasta los resistentes simultáneamente a siete antibióticos, con el 18,4 % de aislamientos resistentes a un antibiótico y el 54,0 % de multirresistentes. Se detectó producción de betalactamasas en el 28,6 % de las cepas procedentes de la región de Puno. También, se observó un mayor número de casos en el rango de edad de 31 a 45 años con resistencia a ceftazidima, ceftriaxona, gentamicina y trimetoprim-sulfametoxazol en el establecimiento de salud de Puno. Conclusión. Los perfiles de resistencia variaron según la localización geográfica del establecimiento de salud, observándose mayor resistencia a los antibióticos en la región de la sierra de Perú, con el 28,6 % de cepas productoras de betalactamasas de espectro extendido. Abstract Introduction: The appearance of multidrug-resistant and beta-lactamase producing enterobacteria in outpatient care facilities represent a public health problem in Perú. Objective: To compare the resistance profiles of uropathogenic Escherichia coli and to identify extended-spectrum beta-lactamase-producing phenotypes in three private health facilities located in the Peruvian coast, Andean and jungle regions. Materials and methods: We conducted a descriptive study on 98 urine samples from Lima (coast), Juliaca (Andean region) and Iquitos (jungle region) during 2016. We determined the antimicrobial susceptibility in 35 samples from Lima, 38 from Juliaca and 25 from Iquitos using eight antibiotic disks in samples from patients diagnosed with urinary infection. We also evaluated the production of extended-spectrum beta-lactamases with cefotaxime and ceftazidime disks and a combination of both with clavulanic acid on Mueller-Hinton agar. Results: We identified 18 resistance profiles ranging from those sensitive to others simultaneously resistant to seven antibiotics: 18.4% resistant to one and 54.0% to multiple antibiotics. We detected beta-lactamase production in 28.6% of the strains from the Puno region. Likewise, we observed a greater number of cases with resistance to ceftazidime, ceftriaxone, gentamicin, and trimethoprim-sulfamethoxazole in Puno’s health facility in patients within the 31 to 45 year age range. Conclusion: Resistance profiles varied according to the geographical location of the health facilities under study. Resistance to antibiotics was higher in the Andean region with 28.6% of strains producing extended-spectrum beta-lactamases.

Objectives Enterococci have gained attention during the past decade as important nosocomial pathogens. Their increasing prevalence has been paralleled by the occurrence of multidrug-resistant and high-level aminoglycoside-resistant strains. This study isolated Enterococcus spp. from hospital samples and determined their antibiotic resistance profile, focusing on aminoglycosides, and associated resistance mechanisms. Methods A total of 195 enterococci from hospital samples in Tehran were studied. Isolates were identified by biochemical reactions. Antimicrobial resistance was determined by disk diffusion. The vancomycin MIC for vancomycin-resistant isolates was determined by agar dilution. Detection of aminoglycoside resistance genes and intI1 and intI2 gene was performed by PCR. Results The majority of isolates were Enterococcus faecalis (65.1%), followed by Enterococcus faecium (31.8%), Enterococcus gallinarum (2.6%) and Enterococcus solitarius (0.5%). According to antibiogram results, 42.1% of isolates were high-level gentamicin-resistant (HLGR) and 40.5% were high-level streptomycin-resistant (HLSR). There was a high prevalence of aac(6')-Ie–aph(2")-Ia (96.3%) among HLGR isolates. ant(6)-Ia and aadA were identified in 93.7% and 64.6% of HLSR isolates, respectively. aph(2ʹʹ)-Ic was detected in 7 isolates (3.6%) and aph(2ʹʹ)-Ib in only 4 isolates (2.1%); no isolates harboured aph(2ʹʹ)-Id, intI1 or intI2. Conclusion Multidrug resistance was higher among HLGR and HLSR isolates compared with non-HLGR and non-HLSR isolates, which may result in limited treatment options. More than 50% of isolates were susceptible to aminoglycosides, thus correct identification in clinical laboratories and administration of these antibiotics can result in decreased used of antibiotics such as vancomycin and linezolid and help to reduce the emergence of resistance to these drugs.

Objectives: Due to the rapid emergence of multidrug-resistant isolates, Campylobacter jejuni (C. jejuni) has been classified as a member of the priority pathogens group. This study aimed to determine the prevalence, antibiotic resistance patterns and source tracking of clinical C. jejuni isolates from paediatric diarrhoeal patients in Pakistan. Methods: A total of 150 stool samples from children were processed for the presence of C. jejuni using culture, biochemical tests and species-specific PCR. Antibiotic susceptibility of the isolates was determined by the disc diffusion method, and metallo-β-lactamase (MBL) producers were detected using gene-specific PCR. Source tracking was performed using source-predictive PCR. Results: C. jejuni was present in 54.6% of the processed samples. More than 80% of the isolated strains were resistant to seven of 12 tested antibiotics. High levels of susceptibility were observed against imipenem (12.2%) and TGC (9.7%). Six isolates (7.3%) were MBL producers and positive for at least one of the five MBL genes. Source tracking showed that 57.3% of the isolates belonged to livestock-associated clusters (C1–C6) and 42.8% were assigned to non-livestock/environmental clusters (C7–C9). Isolates belonging to livestock clusters had a high Multiple Antibiotic Resistance (MAR) index (P < 0.001) as compared with non-livestock. Conclusion: A high prevalence of multidrug-resistant C. jejuni among paediatric diarrhoeal patients was observed. Moreover, the association of these isolates to livestock clades suggests transmission to human populations via the food chain. The presence of imipenem-resistant MBL-producing C. jejuni can lead to serious public health concerns.

Objectives This study evaluated disc diffusion tests and agar screening for detecting mecA-mediated oxacillin resistance in Staphylococcus lugdunensis (S. lugdunensis). Methods Staphylococcus lugdunensis isolates (n = 179) from diverse sources in Hong Kong during 1998–2018 were investigated by disc diffusion tests (cefoxitin and oxacillin) and inoculation onto oxacillin (1 μg/mL and 2 μg/mL) and chromID methicillin-resistant Staphylococcus aureus (MRSA) agars. The results were compared with mecA PCR as the reference. Isolates with discordant results were further tested by MIC and penicillin-binding protein 2a (PBP2a) assays. Results Cefoxitin and oxacillin zone diameters were not distributed in ways that allowed reliable division of the mecA-positive (n = 52) and mecA-negative (n = 127) isolates. On applying the 2019 Clinical Laboratory Standards Institute (CLSI) M100 breakpoints for cefoxitin disc results, there was 88% categorical agreement (CA) and 40% very major error (VME). Screening using 2 μg/mL oxacillin agar reliably differentiated mecA-positive and mecA-negative isolates (100% CA) without any major error (ME) or VME results. The performance of screening using 1 μg/mL oxacillin agar or ChromID MRSA agar was variable (74–89% CA, 0–38% ME and 0–37% VME). The mecA-positive isolates (n = 21) that could not be detected by the cefoxitin disc test were further characterised. The cefoxitin MIC for all 21 isolates was ≤4 μg/mL. Twenty isolates had an oxacillin MIC of 1–2 μg/mL and one had an oxacillin MIC of 4 μg/mL. All had positive PBP2a results and were typed as clonal cluster 27/SCCmec V. Conclusions These findings highlight the need to evaluate phenotypic methods using mecA-positive S. lugdunensis with different oxacillin resistance phenotypes.

© 2021 Elsevier B.V.This work addresses the mathematical model building to detect the diameter of the inhibition zone of gilaburu (Viburnum opulus L.) extract against eight different Fusarium strains isolated from diseased potato tubers. Gilaburu extracts were obtained with acetone, ethanol or methanol. The isolated Fusarium strains were: F. solani, F. oxysporum, F. sambucinum, F. graminearum, F. coeruleum, F. sulphureum, F. auneaceum and F. culmorum. In general, it was observed that ethanolic extracts showed highest antifungal activity. The antifungal activity of extracts was evaluated with machine learning (ML) methods. Several ML methods (classification and regression trees (CART), support vector machines (SVM), k-Nearest Neighbors (k−NN), artificial neural network (ANN), ensemble algorithms (EA), AdaBoost (AB) algorithm, gradient boosting (GBM) algorithm, random forests (RF) bagging algorithm and extra trees (ET)) were applied and compared for modeling fungal growth. From this research, it is clear that ML methods have the lowest error level. As a result, ML methods are reliable, fast, and cheap tools for predicting the antifungal activity of gilaburu extracts. These encouraging results will attract more research efforts to implement ML into the field of food microbiology instead of traditional methods.

Spread of multi-drug resistant (MDR) bacteria in natural environments pose a risk to human and animal health. Wild birds are considered to be reservoirs of human pathogens and vectors of antimicrobial resistance distribution in the environment. The aim of this study is to assess the occurrence of antibiotic resistant bacteria in isolates from bird specimens living in three agro-pastoral areas of the southeastern Sicily. We analyzed the microbiomes of the Eurasian Stone curlew Burhinus oedicnemus (Charadriiformes, Aves) and identified 91 Gram positive and 212 Gram negative strains, whose antimicrobial susceptibility to 11 and 9 antibiotic classes (respectively) was evaluated using agar disk diffusion test. Isolates showed significant levels of antimicrobial resistance, and a high percentage of MDR strains was found both between the Gram positive (49.4%) and the Gram negative (34.9%). Multi-drug resistance levels are higher among strains isolated in the beak and the eye than among enteric (faeces and cloaca) strains. Our results indicate high levels of MDR strains among wild bird populations, with a potential threat to wildlife and human populations., Microbiology; Environmental science; Environmental health; Epidemiology; Infectious disease; Bacteriology; Antibiotic resistant bacteria; Disk diffusion antimicrobial tests; Drug resistance; Gram negative bacteria; Gram positive bacteria; Burhinus oedicnemus; Sicily

Objectives: Invasive candidiasis has a high impact on morbidity and mortality in hospitalised patients. Accurate and timely methods for identification of Candida spp. and determination of echinocandin susceptibility have become a priority for clinical microbiology laboratories. Methods: This study was performed to compare matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) identification with sequencing of the D1/D2 region of the rRNA gene complex 28 subunit in 147 Candida spp. isolates obtained from patients with candidaemia. Antimicrobial susceptibility testing was performed by broth microdilution (BMD) and Etest. Sequencing of the FKS1 and FKS2 genes was performed. Results: The most common species isolated were Candida albicans (40.8%), followed by Candida parapsilosis (23.1%) and Candida tropicalis (17.0%). Overall agreement between the results of identification by MALDI-TOF/MS and molecular identification was 99.3%. Anidulafungin and caspofungin susceptibility by the BMD method was 98.0% and 88.4%, respectively. Susceptibility to anidulafungin and caspofungin by Etest was 93.9% and 98.6%, respectively. Categorical agreement between Etest and BMD was 91.8% for anidulafungin and 89.8% for caspofungin, with lower agreements in C. parapsilosis for anidulafungin (76.5%) and C. glabrata for caspofungin (40.0%). No mutations related to resistance were found in the FKS genes, although 54 isolates presented synonymous polymorphisms in the hotspots sequenced. Conclusions: MALDI-TOF/MS is a good alternative for routine identification of Candida spp. isolates. DNA sequencing of the FKS genes suggested that the isolates analysed were susceptible to echinocandins; alternatively, unknown resistance mechanisms or limitations related to antifungal susceptibility tests may explain the resistance found in a few isolates. © 2017 International Society for Chemotherapy of Infection and Cancer

International audience; The emergence of antibiotic-resistant Yersinia pestis strains represents a public health concern. Two antibiotic-resistant Y. pestis strains isolated from Madagascar have been previously identified and characterised. Both strains carried conjugative plasmids that conferred resistance to streptomycin or to multiple antibacterial drugs, respectively. Here we characterised a novel Y. pestis strain (IP2180H) that exhibited resistance to doxycycline. This strain was isolated from a rat in Antananarivo (Madagascar) in 1998. Resistance was carried by a conjugative plasmid (pIP2180H) homologous to pB71 from Salmonella enterica. The plasmid of the previously identified streptomycin-resistant Y. pestis strain was also sequenced and it was found that the three antibiotic resistance Y. pestis plasmids sequenced until now are genetically unrelated and are also unrelated to multidrug resistance plasmids from the phylogenetically close bacterial species Yersinia pseudotuberculosis. The fact that the three antibiotic-resistant Malagasy Y. pestis strains were isolated from different hosts, at different times, from distant locations, and carried unrelated plasmids indicates independent horizontal acquisition of genetic material and further demonstrates the capacity of Y. pestis to acquire antibiotic resistance plasmids under natural conditions. Since these resistance plasmids can frequently carry or easily trap antibiotic resistance cassettes, the emergence of new multidrug-resistant Y. pestis strains may be expected and would represent a major health threat.

Tigecycline is regarded as a last-resort treatment for multidrug-resistant Acinetobacter baumannii. However, tigecycline resistance in A. baumannii has increased worldwide. In this study, we investigated tigecycline heteroresistance in A. baumannii isolates from South Korea. Antibiotic susceptibility testing was performed on 323 nonduplicated A. baumannii isolates. Among 260 and 37 tigecycline-susceptible and -intermediate-resistant A. baumannii isolates, 146 (56.2%) and 22 (59.5%) isolates were identified as heteroresistant to tigecycline through a disk diffusion assay and population analysis profiling. For selected isolates, an in vitro time-kill assay was performed, and survival rates were measured after preincubation with diverse concentrations of tigecycline. Heteroresistant isolates showed regrowth after 12 h of 2× MIC of tigecycline treatment, and resistant subpopulations were selected by preexposure to tigecycline. Furthermore, genetic alterations in adeABC, adeRS, and rpsJ were assessed, and the relative mRNA expression levels of adeB and adeS were compared. The tigecycline resistance in subpopulations might be due to the insertion of ISAba1 in adeS, leading to the overexpression of the AdeABC efflux pump. However, the tigecycline resistance of subpopulations was not stable during serial passages in antibiotic-free medium. The reversion of tigecycline susceptibility by antibiotic-free passages might occur by additional insertions of ISAba10 in adeR and nucleotide alterations in adeS in some mutants. Tigecycline heteroresistance is prevalent in A. baumannii isolates, which results in treatment failure. Tigecycline resistance is mainly due to the overexpression of the AdeABC efflux pump, which is associated with genetic mutations, but this resistance could be reversed into susceptibility by additional mutations in antibiotic-free environments. IMPORTANCE The evidence that antibiotic heteroresistance is responsible for treatment failure in clinical settings is increasing. Thus, detection and characterization of heteroresistance would be important for appropriate therapeutic guidance to treat bacterial infections. However, data on tigecycline heteroresistance in Gram-negative bacteria is currently limited, although tigecycline is regarded as a last-line antibiotic against infections caused by antibiotic-resistant pathogens. In this study, we investigated the tigecycline heteroresistance in Acinetobacter baumannii, which has been listed by the WHO as a priority for research and development of new antibiotics. We found very high prevalence of tigecycline-heteroresistant A. baumannii clinical isolates, which may result in treatment failure due to the selection of resistant subpopulations. We also identified the main resistance mechanism in tigecycline-resistant subpopulations, that is, upregulation of AdeABC efflux pumps due to ISAba1 insertion in adeS.

Current methods for screening small molecules that inhibit the plasmid pCD1-encoded Yersinia pestis type III secretion system (T3SS) include lengthy growth curves followed by multistep luminescence assays or Western blot assays to detect secretion, or lack thereof, of effector proteins. The goal of this research was to develop a novel disk diffusion assay on magnesium oxalate (MOX) agar as a simple way to evaluate the susceptibility of Y. pestis to type III secretion system inhibitors. MOX agar produces distinct Y. pestis growth characteristics based on the bacteria’s ability or inability to secrete effector proteins; small, barely visible colonies are observed when secretion is activated versus larger, readily visible colonies when secretion is inhibited. Wild-type Y. pestis was diluted and spread onto a MOX agar plate. Disks containing 20 μl of various concentrations of imidocarb dipropionate, a known Y. pestis T3SS inhibitor, or distilled water (dH2O) were placed on the plate. After incubation at 37°C for 48 h, visible colonies of Y. pestis were observed surrounding the disks with imidocarb dipropionate, suggesting that T3S was inhibited. The diameter of the growth of colonies surrounding the disks increased as the concentration of the T3SS inhibitor increased. Imidocarb dipropionate was also able to inhibit Y. pestis strains lacking effector Yops and Yop chaperones, suggesting that they are not necessary for T3S inhibition. This disk diffusion assay is a feasible and useful method for testing the susceptibility of Y. pestis to type III secretion system inhibitors and has the potential to be used in a clinical setting. IMPORTANCE Disk diffusion assays have traditionally been used as a simple and effective way to screen compounds for antibacterial activity and to determine the susceptibility of pathogens to antibiotics; however, they are limited to detecting growth inhibition only. Consequently, antimicrobial agents that inhibit virulence factors, but not growth, would not be detected. Therefore, we developed a disk diffusion assay that could detect inhibition of bacterial virulence factors, specifically, type III secretion systems (T3SSs), needle-like structures used by several pathogenic bacteria to inject host cells with effector proteins and cause disease. We demonstrate that magnesium oxalate (MOX) agar can be used in a disk diffusion assay to detect inhibition of the T3SS of Yersinia pestis, the causative agent of bubonic plague, by small-molecule inhibitors. This assay may be useful for screening additional small molecules that target bacterial T3SSs or testing the susceptibility of patient-derived samples to drugs that target T3SSs.

Introduction:Marsdenia macranthais a crucial source of traditional medicine in Northern Namibia. Its roots are used to treat various health conditions ranging from mouth infections to urinary retention. Despite its medicinal application, there is no known knowledge of its therapeutic properties. Thus, we investigated the phytochemical content and antibacterial activity ofM. macrantha. Methods:M. macrantharoot extracts were obtained using three different solvents (distilled water, methanol and acetone) - in the soxhlet and maceration extraction methods. Total phytochemical (terpenoid, alkaloid and/or flavonoid) content was determined by spectrophotometry. Antibacterial activity against common foodborne pathogens (Staphylococcus aureus,Escherichia coliandSalmonella typhi) was determined by both well and disc diffusion method. Results:we detected the presence of all the tested phytochemicals. Methanol gave the highest percentage yield of extraction (mean: 13.95 ± standard deviation: 0.41%) followed by water (10.92 ± 0.11%) and acetone (6.85 ± 0.23%), F-ratio=326.71 and p

Transparent materials used for facial protection equipment provide protection against microbial infections caused by viruses and bacteria, including multidrug-resistant strains. However, transparent materials used for this type of application are made of materials that do not possess antimicrobial activity. They just avoid direct contact between the person and the biological agent. Therefore, healthy people can become infected through contact of the contaminated material surfaces and this equipment constitute an increasing source of infectious biological waste. Furthermore, infected people can transmit microbial infections easily because the protective equipment do not inactivate the microbial load generated while breathing, sneezing or coughing. In this regard, the goal of this work consisted of fabricating a transparent face shield with intrinsic antimicrobial activity that could provide extra-protection against infectious agents and reduce the generation of infectious waste. Thus, a single-use transparent antimicrobial face shield composed of polyethylene terephthalate and an antimicrobial coating of benzalkonium chloride has been developed for the next generation of facial protective equipment. The antimicrobial coating was analyzed by atomic force microscopy and field emission scanning electron microscopy with elemental analysis. This is the first facial transparent protective material capable of inactivating enveloped viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in less than one minute of contact, and the methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. Bacterial infections contribute to severe pneumonia associated with the SARS-CoV-2 infection, and their resistance to antibiotics is increasing. Our extra protective broad-spectrum antimicrobial composite material could also be applied for the fabrication of other facial protective tools such as such as goggles, helmets, plastic masks and space separation screens used for counters or vehicles. This low-cost technology would be very useful to combat the current pandemic and protect health care workers from multidrug-resistant infections in developed and underdeveloped countries.

This study is aimed at identifying the chemical composition of the essential oil extracted from the Syzygium aromaticum seeds, as well as investigating its biological activities, insecticide effect, and allelopathic properties. The extraction yield was about 14.3 and 7.14% for grounded and ungrounded seeds, respectively. The GC-MS analysis allowed the identification of 17 heterogeneous compounds, including eugenol (68.7-87.4%), as major compound, cyperene (20.5-7.2%), phenethyl isovalerate (6.4-3.6%), and cis-thujopsene (1.9-0.8%), respectively, for grounded and ungrounded seeds. Concerning the antibacterial activity, the diameter of the inhibition zone reached 35 mm when the essential oil extracted from grounded seeds was applied against Escherichia coli. Regarding the antioxidant activity via the DPPH radical scavenging test, the IC 50 varied from 1.2 ± 0.1 to 2.8 ± 0.5 μ g / mL . With respect to reducing power, the efficient concentration EC 50 ranged from 32 to 50 μg/mL. The essential oil exhibited also an allelopathic effect against seeds of Hyoscyamus niger, as well as an insecticide effect against Sitophilus oryzae with a DL 50 value of 252.4 μL/L air. These findings enhance the use of this spice as a natural food preservative and encourage its use in several fields, including pharmaceutical, cosmetics, agriculture, and therapy, that could be a strategic way to guarantee the consumer’s health.

Objectives Polymyxin resistance has been increasing in many regions, and appropriate determination of polymyxin susceptibility is now a major challenge worldwide. Many clinical laboratories rely on gradient diffusion methods to assess polymyxin susceptibility, although broth microdilution (BMD) is the only method currently recommended by the CLSI and EUCAST. The aim of this study was to assess the performance of the polymyxin B (PMB) Etest in a setting with a high prevalence of KPC-producing Klebsiella pneumoniae (KPC-KP). Methods A commercial Etest susceptibility testing method was evaluated and compared with the reference BMD method, considering isolates with a minimum inhibitory concentration (MIC) ≤2 mg/L for PMB as susceptible to this drug. A total of 310 clinical KPC-KP isolates were evaluated. Results Susceptibility was significantly higher by Etest compared with BMD (82.6% vs. 75.8%). The MIC50, MIC90 and modal MICs for PMB were 0.25, 32 and 0.25 mg/L (27.1%) by BMD and 0.5, 16 and 0.5 mg/L (49.7%) by Etest, respectively. Although categorical agreement was 90.0%, there was poor essential agreement (50.6%). A high rate (34.7%) of very major errors (VMEs) and a relatively low rate (2.1%) of major errors were found. Conclusion The considerable number of resistant isolates in this study allowed an accurate estimation of VME rates and, consequently, a more comprehensive assessment of susceptibility testing for polymyxins. Etest did not meet fully the acceptance criteria for US FDA requirements. These data do not support the use of this commercial method for determining PMB MICs in carbapenem-resistant Enterobacterales populations.

Background The existing modified carbapenem inactivation methods (mCIMs) recommended by the CLSI for detecting carbapenemase production have not been applicable for Acinetobacter baumannii. We evaluated the influence of matrices used in mCIMs and CIMTris on the stability of the disks for detecting carbapenemase producers and suggested optimal mCIM conditions for detecting carbapenemase-producing A. baumannii. Methods Seventy-three A. baumannii isolates characterized for antimicrobial susceptibility and carbapenemase encoding genes were tested for carbapenemase production using mCIM and CIMTris. The influence of the matrices (Tryptic soy broth [TSB] and Tris-HCl) used in these methods on the stability of the meropenem (MEM) disk was also evaluated. The mCIM conditions were adjusted to enhance screening sensitivity and specificity for detecting carbapenemase-producing A. baumannii. Results The matrices had an impact on the stability of the MEM disk after the incubation period (two or four hrs). TSB nutrient broth is an appropriate matrix for mCIM compared with Tris-HCl pH 7.6, which leads to the loss of MEM activity in CIMTris. The sensitivity and the specificity of the optimal mCIM were both 100%. Conclusions We established optimal mCIM conditions for simple, accurate, and reproducible detection of carbapenemase-producing A. baumannii.

Colistin is one of the most effective alternatives for treating Acinetobacter baumannii infections. The aim of this study was to determine colistin resistance and heteroresistance rates in A. baumannii from clinical samples in Hacettepe University clinical microbiology laboratory between June 2016 and January 2017. A total of 200 isolates were included in the study. In vitro susceptibility to amikacin, gentamicin, ceftazidime, piperacillin/tazobactam, meropenem, ciprofloxacin, and tigecycline were determined by disk diffusion test. Most isolates were multiresistant as they exhibited resistance to aminoglycosides, β-lactams, and fluoroquinolones. Colistin susceptibility was determined by broth microdilution (BMD) test (EUCAST standards) and was compared with E-test (bioMérieux, France) in 120 isolates. In 14 blood isolates that were susceptible to colistin (MIC ≤ 2 mg/L), heteroresistance was investigated with the population analysis profile (PAP) method. Overall resistance (n = 200) to colistin was 28% by BMD. Among the 120 isolates where the two tests were compared, resistance to colistin was 25.8% versus 4.2% with BMD and E-test, respectively. Three blood isolates (21.4%) were heteroresistant to colistin. With E-test, a majority of the resistant isolates are overlooked and in vitro susceptibility to colistin should be determined with broth dilution method. This is the first study in Turkey reporting heteroresistance in A. baumannii isolates by the PAP method and emphasizes the need to test for heteroresistance in relation to clinical outcome in serious infections due to A. baumannii.

Purpose In this study, we aimed reviewed the data about the patterns of antimicrobial susceptibility and resistance determinants among carbapenem-resistant Acinetobacter baumannii (CRAB) from patients with burn injury. Methods A systematic review was conducted using the PRISMA statement in PUBMED/MEDLINE, Scopus, Scientific Electronic Library Online (SciELO), Biblioteca Virtual de Saude (BVS) and Cochrane Library. The data referring to enzymatic resistance mechanisms were evaluated by meta-analyses according to random effect. Results 17 articles that evaluated 1226 CRAB recovered from patients with burn injury were included in study. The majority of studies are from Iran (12/17; 70.6%), published in 2016 (6/17; 35.3%) and showed prospective design (15/17; 88.2%). The samples were obtained mainly from burn wounds (14/17; 82.3%) and more than half of the studies did not identify if the isolates originated from infected or colonized patients (10/17; 58.8%). Second the meta-analyses, OXA-type carbapenemase was the main mechanism involved in low susceptibility to carbapenems (53.2%; 95% CI = 60, 80.0%, I2 = 86.0%), followed by metallo-β-lactamases (MBL) (30.2%; 95% CI = 11, 42.0%, I2 = 93.0%), and Klebsiella pneumoniae carbapenemase (KPC) (16.6%; 95% CI = 5, 63.0%, I2 = 88.0%). The majority of strains harbored blaOXA-23-like (12/17; 70.6%) or blaOXA-24/40-like (12/17; 35.3%) genes. The studies included showed that minocycline (69.5%) and colistin (99.9%) susceptibility remains high and is not impacted by carbapenem resistance in these isolates. Conclusions The results summarized in this review indicate the importance of a high-quality surveillance program to design suitable and effective interventions to control CRAB infection in burn units worldwide.

Objective: Resistance against a wide variety of antibiotics is one of the prominent characteristics of Acinetobacter baumannii. The purpose of this study was to investigate the in vitro susceptibility testing of A. baumannii isolates to rifampin and the examination of the value of routine antibiogram with disk diffusion, E-test, and agar dilution methods on collected isolates from a tertiary hospital in north-west Iran. Materials and Methods: Susceptibility of 68 clinically isolated A. baumannii against rifampin using three in vitro methods was investigated. For the E-test method, the Pachon–Ibanez's and Saballs's study criteria were used. The Pachon–Ibamez criteria were used for agar dilution method. For disk diffusion, the standard Kirby–Bauer diffusion method was used. The area under curve (AUC) was used to determine the appropriate methods. The methods were interpreted using sensitivity, specificity, and negative and positive predictive values. Results: A. baumannii susceptibility to the rifampin according to the E-test was 41.2% (Panchon–Ibanez criteria) and 32.4% (Saballs's criteria). The susceptibility was 29.4% according to the agar dilution method for the Panchon–Ibanez criteria, 2.9% according to the agar dilution method for the Saballs's criteria and, and 1.5% according to the disk diffusion methods. The results of the E-test method according to Pachon–Ibanez's and Saballs's criteria in comparison with the result of the agar dilution method according to Pachon–Ibanez's criteria had the highest AUC. Conclusion: According to the susceptibility testing of rifampin against A. baumannii, the E-test method has a higher diagnostic value than the agar dilution and disk diffusion methods.

Blood stream infection with extensively drug-resistant-carbapenamase producing Klebsiella (K.) pneumoniae usually represents a major threat with medical challenges among hospitalized cancer patients with poor functional status and underlying diseases. Accordingly, the aim of the study was to evaluate the efficacy of different antibiotics either alone or in combinations against extensively drug-resistant-OXA-48 producing K. pneumoniae clinical isolates that were previously recovered from febrile neutropenic pediatric cancer patients. The antimicrobial activity of amikacin, gentamicin, colistin, ertapenem, imipenem, meropenem and tigecycline was assessed by broth microdilution method. The results revealed that all the tested OXA-48 producing K. pneumoniae isolates exhibited extensively drug-resistant phenotype and all of them were susceptible to tigecycline. Checkerboard method was used to determine the fraction inhibitory concentration index, to further classify the effect of antibiotic combination as synergistic, additive, indifferent, or antagonistic effect. The results revealed that in vitro dual carbapenem combination of ertapenem with meropenem had shown synergistic effect against all of the tested isolates. Additionally, synergistic effect of meropenem with colistin was detected among three of four isolates tested. Herein we investigated the in vivo activity of colistin, meropenem alone and in combination in a rat thigh infection model. The results showed that addition of meropenem to colistin was not effective at reduction of bacterial count as compared to colistin alone at 24 h post treatment. Accordingly, we can conclude that in vitro antibiotic combinations of dual carbapenems (ertapenem plus meropenem) and meropenem plus colistin showed synergism in 100% and 75% of the tested isolates, respectively. Colistin alone had significantly reduced bacterial count while its combination with meropenem was not superior to monotherapy in murine thigh infection model. Impact statement The present study aimed to evaluate the effectiveness of various antibiotics both in vitro and in vivo using murine animal model either alone or in combination against various strains of extensively drug-resistant (XDR) Klebsiella pneumoniae, life-threatening pathogens of relevant medical importance isolated from febrile neutropenic pediatric cancer patients. This work also emphasizes how to select the appropriate antibiotics options and help the physicians to choice the appropriate antibiotic for the treatment of such superbugs (extensively drug-resistant (XDR) Klebsiella pneumoniae). The results showed that in vitro dual carbapenem combination of ertapenem with meropenem had shown synergistic effect against all of the tested XDR isolates. Antibiotic combinations of dual carbapenems and meropenem plus colistin showed synergism in 100% and 75% of the testes isolates, respectively. Results of the in vivo evaluation, colistin alone had significantly reduced bacterial count while its combination with meropenem was not superior to monotherapy.

BACKGROUND: Helicobacter pylori infection in Chile remains as a public and private health-care system’s challenge, with a prevalence of the infection over 70%. Nowadays, antibiotic treatment of the infection is mandatory to prevent the arising of severe associated diseases but failures in the eradication therapy mainly due to clarithromycin resistance has been observed worldwide and first line eradication therapy seems to be not effective anymore in several geographical areas. Thus, health-care systems are committed to maintain an epidemiological surveillance upon the evolution of the antibiotic resistance of this priority 2 pathogen. OBJECTIVE: This work reports a 10 years surveillance of the primary antibiotic resistance of H. pylori clinical isolates at the Biobío region-Chile, and the evolution of resistance toward amoxicillin, clarithromycin, levofloxacin, metronidazole, and tetracycline among the species. METHODS: H. pylori strains were investigated during the periods 2005-2007 (1435 patients analysed) and 2015-2017 (220 patients analysed) by inoculating a saline homogenate biopsy onto the surface of Columbia agar (Oxoid, Basingstoke, UK) - supplemented with 7% horse red blood cells plus DENT inhibitor (Oxoid, Basingstoke, UK) - following by incubation at 37ºC under 10% CO2 atmosphere for five days. Antibiotic resistance pattern of the isolates was assessed using the disk diffusion test in Müeller-Hinton agar supplemented with 7% horse red blood cells followed by incubation for further three days under 10% CO2 atmosphere. Statistical analysis was done using the SPSS v22 software and P values

Introduction: Campylobacter jejuni is one of the major causes of gastroenteritis worldwide of the last century. The aim of this study was to investigate the antibiotics profiles and the virulence gene in C. jejuni strains isolated from chicken in Côte d’Ivoire. Methodology: A total of 336 chicken ceaca samples recovered from market of two municipality of Abidjan were examined by conventional microbiological methods and molecular test using PCR. The antibiotic susceptibility tests of the isolates were determined by disk diffusion method. The presence of virulence genes was examined using simple PCR method. Results: Among of 336 samples, 168 (50%) were positives for C. jejuni. Among the C. jejuni isolates, 159 strains (94.64%) were resistant to one or more antimicrobial agents. The highest percentage of antimicrobial resistance was found for Nalidixic acid (85.33%), Tétracyclin (71.76%) and Ciprofloxacin (55.65%). Moreover, MDR including 3, 4, 5 and 6 antibiotics families was detected in 16.66% of isolates. On the other hand, detection of virulence putative gene shows presence of cadF in 100% of tested strains. In addition, cdtA, cdtB and cdtC genes were detected in 100%; 89.51% and 90.32% respectively of C. jejuniisolates. Conclusion: Because of the key role of broiler chicken in human campylobacteriosis infection, it will important in first time to monitoring using of antibiotics in chicken farms and in second time to verify presence of campylobactériosis in country.

Silver nanoparticles (AgNPs) have great potential for their mechanistic role in biomedical researches. Recently, green biosynthetic approaches have been received much attention in plant science for nanoparticles production. Therefore, in the present study AgNPs have been synthesized utilizing in-vitro grown leaf extract of anti-diabetic medicinal plant Withania coagulans Dunal by the reduction of silver nitrate solution. W. coagulans synthesized silver nanoparticles (WcAgNPs) were characterized by UV–visible spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, X-ray powder diffraction and Fourier transform Infra-Red spectroscopy. All cumulative results showed that WcAgNPs were ~14 nm in size having spherical shape with face centered cubic structure. High performance liquid chromatography confirmed the involvement of withanolides in AgNPs synthesis as a reducing/capping agent. Synthesized WcAgNPs showed greater antioxidative potential when compared with W. coagulans leaf extract. WcAgNPs have efficient antimicrobial potential and suppresses the growth of both gram positive and gram negative bacteria. In our finding we also observed cytotoxicity of WcAgNPs against SiHa (cervical cancerous, hyper-triploid) cell lines and apoptosis in SiHa cells after 48 hour incubation with 13.74 μg ml−1 (IC50) concentration of WcAgNPs. As results suggested, this is the first report which explain that W. coagulans leaf extract have potential as bio-reducing agent for synthesis of silver nanoparticles, which can be exploited as anti-oxidant, antimicrobial and anti-cancerous agent and depicting an effective way for utilizing bioactive resources in restoration of medicinal properties of this plant with high efficacy.

Multi-drug resistant cervicovaginal Escherichia coli (CVEC) infections are a serious health problem. The aim of this study is to determine the patterns of virulence genes, antibiotic resistance and O-serogroups of CVEC isolated in Mexico. Two hundred strains of CVEC were isolated from women attending two Clinics at the Instituto Mexicano del Seguro Social. E. coli O-serogroups and virulence markers were identified by PCR. Antibiotic susceptibility was determined using the Kirby-Bauer disc-diffusion method. Serogroups O25 (50%), O75 (9%) and O15 (7.5%) were the most frequent among the CVEC strains isolated. The frequencies for antibiotic resistance were ampicillin 97%, (n = 194); carbenicillin 93.5%, (n = 187); cefalotin 77%, (n = 154); and nitrofurantoin 71%, (n = 142). The frequency of multiresistant isolates (3–12 drugs) was 197 (98.5%). The most frequent virulence genes found were feoB (91.5%), fimH (89.5%), kpsMT11 (75%), iutA (66%), and iroN (59%). One hundred and four distinct patterns of virulence markers with antibiotic-resistance genes associated with O-serogroups were identified amongst CVEC isolates. In conclusion: most CVEC strains isolated were multiresistant to antibiotics, belonged to three O-serogroups, and possessed a battery of virulence factors. This knowledge may lead to improved guidelines and standards for treating cervicovaginal infections.

This study evaluated the diagnostic test accuracy of disc diffusion relative to broth-microdilution for clinical Staphylococcus pseudintermedius isolated from dogs in Australia (n = 614). Accuracy of disc diffusion and broth-microdilution for oxacillin relative to mecA real-time PCR was also assessed. Each isolate had paired minimum inhibitory concentration and zone diameter values for ten antimicrobial agents. Data was dichotomised using Clinical and Laboratory Standards Institute susceptible and resistant clinical breakpoints. Test accuracy was reported using relative diagnostic sensitivity (RSe), specificity (RSp), likelihood ratio pairs, diagnostic odds ratio, and area-under-the receiver-operating characteristic (ROC AUC) analysis. Disc diffusion was found to have high test accuracy for most antimicrobials (ROC AUC range: 0.96 – 0.99) except rifampicin (ROC AUC = 0.80). The RSp of disc diffusion was high for all antimicrobials (range, 97.1%–100%). However, RSe was considerably variable (range, 35.7%–98.8%), particularly for amoxicillin-clavulanic acid (51.5%, 95% CI, 38.9%, 64.0%), cefoxitin (35.7%, 95% CI, 12.8%, 64.9%), and cephalothin (43.6%, 95% CI, 27.8%, 60.4%). When disc diffusion and broth-microdilution were compared to mecA real-time PCR, the overall accuracy of both assays was similar (ROC AUC, 0.99 respectively). However, the RSe for broth-microdilution (96.1%, 95% CI, 88.9%, 99.2%) was significantly higher than for disc diffusion (86.8%, 95% CI, 77.1%, 93.5%) (McNemars mid-p value 0.01). Overall, these findings demonstrate that for most antimicrobials, disc diffusion performed according to CLSI guidelines can be used to differentiate clinical S. pseudintermedius isolates that might otherwise be assessed by broth-microdilution, provided consideration is given to the performance estimates reported here.

Nocardia spp. is a pathogen responsible for a variety of clinical infections, ranging from skin and soft tissue infections, to the respiratory tract and central nervous system infections. Its epidemiological characteristics, including species distribution, clinical features, and antimicrobial susceptibility profiles, should be under surveillance for the prevention and treatment of nocardiosis. In the present study, over a 9-year period (from 2009 to 2017), 53 non-repetitive Nocardia isolates were collected from 8 tertiary general hospitals of 7 cities in China. These isolates were identified to species level by multilocus sequence analysis(MLSA). The clinical data were also reviewed. The susceptibilities to 10 commonly-used antibiotics for Nocardia were determined by E-test stripes, and the resistance rates, MIC50 and MIC90 to each antibiotic by different species were analyzed. Of 53 Nocardia isolates, N. farcinica was the most common species (24.5%, 13/53), followed by N. cyriacigeorgica (20.8%, 11/53), N. terpenica (15.1%, 8/53), N. abscessus (9.43%, 5/53), N. otitidiscaviarum (7.55%, 4/53), respectively. Furthermore, 31 Nocardia (58.5%) isolates were recovered from lower respiratory tract (sputum and BALF), 15 (28.3%) from superficial Infection, 3 (5.7%) from pleural effusion, 2 (3.8%) from CSF, and 1 from bone marrow and 1 from synovial fluid, respectively. The antibiotic resistance profiles varied between different Nocardia species. All Nocardia isolates were susceptible to linezolid, followed by imipenem and amikacin (both 92.5% susceptibility rate). N. terpenica, rarely documented elsewhere, showed a different antimicrobial susceptibility profile. In summary, herein, the clinical and antibiotic resistance features of Nocardia species reported would be helpful for understanding the diversity of Nocardia species circulating in China and for decision making in the context of empiric therapy.

Staphylococcus lugdunensis is a coagulase-negative staphylococcus (CoNS) with unusual pathogenicity resembling that of S. aureus. Unlike other CoNS, S. lugdunensis remains susceptible to most antibiotics. The resistance to penicillin varies widely (range, 15–87% worldwide), whereas methicillin resistance is still rare. We aimed to evaluate treatment options for infections caused by S. lugdunensis and more specifically to investigate whether penicillin G could be a better treatment choice than oxacillin. Susceptibility testing was performed using the disc diffusion method for penicillin G, cefoxitin, trimethoprim/sulfamethoxazole, erythromycin, clindamycin, gentamicin, norfloxacin, fusidic acid, rifampicin, and fosfomycin. Isolates susceptible to penicillin G were further tested with a gradient test for penicillin G and oxacillin. Of the 540 clinical isolates tested, 74.6% were susceptible to penicillin G. Among these penicillin-susceptible isolates, the MIC50 and MIC90 values for penicillin G were threefold lower than that for oxacillin. A majority of the isolates were susceptible to all other antibiotics tested. Breakpoints for fosfomycin have not yet been defined, and so no conclusions could be drawn. Two isolates were resistant to cefoxitin and carried the mecA gene; whole-genome sequencing revealed that both harbored the SCCmec element type IVa(2B). S. lugdunensis isolated in Sweden were susceptible to most tested antibiotics. Penicillin G may be a more optimal treatment choice than oxacillin. Although carriage of the mecA gene is rare among S. lugdunensis, it does occur. Electronic supplementary material The online version of this article (10.1007/s10096-019-03571-6) contains supplementary material, which is available to authorized users.

Pseudomonas aeruginosa PAO1 (tobramycin MIC = 0.064 µg/mL) was used to perform agar diffusion tests employing tobramycin-containing tablets. Bacterial growth and formation of inhibition zones were studied by stereomicroscopy and by blotting with microscope slides and staining with methylene blue, Alcian blue and a fluorescent lectin for the P. aeruginosa PSL, which was studied by confocal laser scanning microscopy. Diffusion of tobramycin from the deposit was modelled using a 3D geometric version of Fick's second law of diffusion. The time-dependent gradual increase in the minimum biofilm eradication concentration (MBEC) was studied using a Calgary Biofilm Device. The early inhibition zone was visible after 5 h of incubation. The corresponding calculated tobramycin concentration at the border was 1.9 µg/mL, which increased to 3.2 µg/mL and 6.3 µg/mL after 7 h and 24 h, respectively. The inhibition zone increased to the stable final zone after 7 h of incubation. Bacterial growth and small aggregate formation (young biofilms) took place inside the inhibition zone until the small aggregates contained less than ca. 64 cells and production of polysaccharide matrix including PSL had begun; thereafter, the small bacterial aggregates were killed by tobramycin. Bacteria at the border of the stable inhibition zone and beyond continued to grow to a mature biofilm and produced large amount of polysaccharide-containing matrix. Formation of the inhibition zone during agar diffusion antimicrobial susceptibility testing is due to a switch from a planktonic to biofilm mode of growth and gives clinically important information about the increased antimicrobial tolerance of biofilms.

Introduction: Carbapenemase producing Enterobacteriaceae are emerging as important pathogens worldwide with serious effects on patients’ outcome. The study aimed to investigate the emergence of carbapenemases associated with enterobacterial infection in Western region of Saudi Arabia. Methodology: Clinical isolates from suspected patients with enterobacterial infection were investigated over a one-year period from four tertiary care hospitals of Makkah, Saudi Arabia. All isolates were identified using Vitek-2 system and then screened for potential carbapenemase production using disk diffusion test. Suspected isolates with reduced susceptibility to carbapenems were further investigated for blaNDM-1, blaKPC and blaOXA-48 resistant genes. Results: Out of 120 confirmed Enterobacteriaceae isolates, Klebsiella pneumoniae and Escherichia coli comprised the largest proportion (35% and 34.2%, respectively) of encountered infections. Twenty-six (21.7%) isolates showed resistance to carbapenems, the majority of which (21/26) were K. pneumoniae. Remarkably, 17 isolates carried triple resistant genes KPC/NDM-1/OXA-48 while the other 4 carried double resistant genes (KPC/OXA-48) or (NDM-1/OXA-48). The current study revealed that the mentioned triple resistance genes have the higher incidence with significant association risk among males (COR 4.5; CI: 1.9-17.3; P = 0.018), non-Saudi nationalities (COR 4.9; CI: 1.5-19.3; P = 0.003), ICU-obtained specimens (COR 3.6; CI: 1.5-8.4; P = 0.002) and blood specimens (COR 2.8; CI: 1.1-6.9; P = 0.02). Conclusion: Multidrug-resistant Enterobacteriaceae isolates in particular K. pneumoniae co-harboring KPC, NDM-1 and OXA-48 genes are emerging in Western region, Saudi Arabia. This is the first record of triple carbapenemase genes co-producing K. pneumoniae associated with enterobacterial infection.

Objectives Ceftriaxone resistance in Neisseria gonorrhoeae is a major public health concern globally because a high-dose (1 g) injection of ceftriaxone is the only remaining option for empirical monotherapy of gonorrhoea. The ceftriaxone-resistant gonococcal strain FC428, cultured in Osaka in 2015, is suspected to have spread nationally and internationally. We describe the complete finished genomes of FC428 and two closely related isolates from Osaka in 2015, and examine the genomic epidemiology of these isolates plus three ceftriaxone-resistant gonococcal isolates from Osaka and Hyogo in 2016-17 and four ceftriaxone-resistant gonococcal isolates cultured in 2017 in Australia, Canada and Denmark. Methods During 2015-17, we identified six ceftriaxone-resistant gonococcal isolates through our surveillance systems in Kyoto, Osaka and Hyogo. Antimicrobial susceptibility testing (six antimicrobials) was performed using Etest. Complete whole-genome sequences of the first three isolates (FC428, FC460 and FC498) from 2015 were obtained using PacBio RS II and Illumina MiSeq sequencing. The three complete genome sequences and draft genome sequences of the three additional Japanese (sequenced with Illumina MiSeq) and four international ceftriaxone-resistant isolates were compared. Results Detailed genomic analysis suggested that the Japanese isolates (FC428, FC460, FC498, KU16054, KM383 and KU17039) and the four international MLST ST1903 isolates from Australia, Canada and Denmark formed four linked subclades. Conclusions Using detailed genomic analysis, we describe the clonal expansion of the ceftriaxone-resistant N. gonorrhoeae strain FC428, initially identified in 2015 in Japan, and closely related isolates. FC428 and its close relatives show some genomic diversity, suggesting multiple genetic subclades are already spreading internationally.

Serotypes and antimicrobial susceptibility of Salmonella’s isolates from broiler production chain were determined. A total of 239 isolated strains from chicken, carcasses, breeding environments, and slaughter was analyzed by disk diffusion test, in the period of 2009 to 2010. For antibiotics with a high number of resistant strains, the minimal inhibitory concentration (MIC) was performed. We identified 24 serotypes, being the most frequent, Minnesota (31.4%) and Infantis (22.6%). The highest percentages of resistance were obtained for sulfonamide (42.7%), followed by tetracycline with 37.6% and amoxicillin with 27.6%. From the total, 32 resistance profiles were identified, being 60.7% of the strains were resistant to at least one antibiotic. Of these, 31.7% of the isolates showed multidrug resistance profiles belonging to serovar Minnesota, Saintpaul, and S. enterica. The highest resistance was found in isolates from slaughterhouse (66.9%) and aviary (58.7%). A large number of strains showed MIC above the maximum tested concentration for the antibiotics amoxicillin and sulfamethoxazole. The high number of Salmonella’s resistant strains indicates the need for prudent use of these drugs in poultry production in order to reduce the occurrence and spread of antibiotic resistance profiles, and the risk that multiresistant strains isolated from broilers may pose a risk to human health.

During the last years, the food industry is working on the replacement of high energy methodologies with more sustainable techniques for the encapsulation of natural preservatives, in order to enhance their effectiveness as food additives. In the present study, nisin, an antimicrobial agent, was encapsulated in essential oil-containing microemulsions. More specifically, rosemary, thyme, oregano, and dittany essential oil-containing microemulsions were formulated to encapsulate nisin enhancing the system's overall antimicrobial activity. The systems were investigated for the interfacial properties and size of the surfactants' monolayer using electron paramagnetic resonance spectroscopy and dynamic light scattering. Subsequently, nisin-loaded microemulsions were tested for their antimicrobial activity against Lactococcus lactis, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus, using the well diffusion assay. Finally, this technique was validated by a killing assay. Overall, this study provides important information on the antibacterial activity of nisin-loaded nano-carriers enhanced by essential oils, in relation to the microemulsions' structure.

Background The global resurgence of pertussis in countries with high vaccination coverage has been a concern of public health. Methods Nasopharyngeal swabs were collected for Bordetella pertussis culture from children with suspected pertussis. Clinical and vaccination information were reviewed through electronic medical chart and immunization record. Antibiotics susceptibility was evaluated using E-test for erythromycin, azithromycin, clarithromycin and sulfamethoxazole/trimethoprim. The MLST genotypes and 7 antigenic genes (ptxP, ptxA, ptxC, Prn, fim3, fim2 and tcfA) of Bordetella pertussis were identified by polymerase chain reaction amplification and sequencing. Results During January 2016 to September 2017, a total of 141 children 1-48 months of age were culture-confirmed with pertussis, of whom 98 (69.5%) were younger than 6 months, 25 (17.7%) had completed at least 3 doses of DTaP and 75 (53.2%) had a clear exposure to household members with persistent cough. Fully vaccinated cases manifested milder disease than unvaccinated and not-fully vaccinated cases. All strains were MLST2. High-virulent strains characteristic of ptxP3/prn2/ptxC2 constituted 41.1% (58/141) and were all susceptible to macrolides while low-virulent strains characteristic of ptxP1/prn1/ptxC1 constituted 58.9% (83/141) and 97.6% (81/83), respectively, were highly resistant to macrolides. Conclusions Pertussis is resurging among infants and young children in Shanghai, and household transmission is the main exposure pathway. The high-virulent strains harboring ptxP3/prn2/ptxC2 and the macrolide-resistant Bordetella pertussis strains are quite prevalent. These issues impose a public health concern in Shanghai. Our findings are important to modify the DTaP vaccination strategy and the management guideline of pertussis in China.

Background Antimicrobial resistance (AMR) in food-producing animals is a global public health issue. This study investigated AMR and virulence profiles of E. coli isolated from healthy chickens in Vietnam. E. coli were isolated from fecal samples collected in five chicken farms located in the provinces of Hoa Binh, Thai Nguyen and Bac Giang in the North of Vietnam. These isolates were examined by disk diffusion for their AMR, PCR for virulence and AMR genes, pulsed-field gel electrophoresis for relatedness between blaCMY-2/blaCTX-M–positive isolates, electroporation for transferability of blaCMY-2 or blaCTX-M genes and sequencing for mutations responsible for ciprofloxacin resistance. Results Up to 99% of indicator isolates were multidrug resistant. Resistance to third-generation cephalosporins (3GC) was encoded by both blaCTX-M and blaCMY-2 genes; blaCTX-M genes being of genotypes blaCTX-M-1, − 14, − 15, − 17, − 57 and − 87, whereas ciprofloxacin resistance was due to mutations in the gyrA and parC genes. Some isolates originating from farms located in different provinces of Vietnam were found to be closely related, suggesting they may have been disseminated from a same source of contamination. Plasmids may also have played a role in the diffusion of 3GC-resistance as the blaCMY-2 gene was located on plasmids A/C and I1, and the blaCTX-M gene variants were carried by I1, FIB, R and HI1. Plasmids carrying the blaCMY-2/blaCTX-M genes also co-transferred resistance to other antimicrobials. In addition, isolates potentially capable of infecting humans, of which some produced blaCMY-2/blaCTX-M, were identified in this study. Conclusions Both clones and plasmids could be involved in the dissemination of 3GC-resistant E. coli within and between chicken farms in Vietnam. These results demonstrate the necessity to monitor AMR and control antimicrobial use in poultry in Vietnam. Electronic supplementary material The online version of this article (10.1186/s12917-019-1849-1) contains supplementary material, which is available to authorized users.

Introduction: In Bangladesh, human sludge from dry pit latrines is commonly applied directly to agricultural lands as manure. This study was conducted to investigate the presence of antibiotic resistance, virulence factors and plasmid contents of E. coli strains isolated from sludge samples. Methodology: E. coli were isolated from human feces from closed pit latrines and identified by culture method. Antibiotic susceptibility patterns of the isolates were determined by Standard Kirby-Bauer disk diffusion method. Pathogenic genes and antibiotic resistance genes of ESBL producing isolates were determined by PCR assay. Results: Of the 34 samples tested, 76.5% contained E. coli. Of 72 E. coli isolates, 76.4% were resistant to at least one of the 12 antibiotics tested and 47.2% isolates were resistant to three or four classes of antibiotics. Around 18% isolates were extended spectrum β- lactamase producing and of them 6 were positive for blaTEM specific gene, 4 for blaCTX-M gene, 1 for blaOXA gene and 2 for both blaTEM and blaCTX-M genes. Moreover, among 72 isolates, 4.2% carried virulence genes of enterotoxigenic E. coli; two isolates were positive for st and one was positive for both st and lt genes. In addition, 59.7% of the isolates contained plasmids (range 1.4 to 140 MDa) of which 19.5% isolates contained a single plasmid and 40.2% contained multiple plasmids. Conclusions: The presence of pathogenic, drug resistant E. coli in human sludge necessitates a regular surveillance before using as a biofertilizer.

Biofouling is a phenomenon that describes the fouling organisms attached to man-made surfaces immersed in water over a period of time. It has emerged as a chronic problem to the oceanic industries, especially the shipping and aquaculture fields. The metal-containing coatings that have been used for many years to prevent and destroy biofouling are damaging to the ocean and many organisms. Therefore, this calls for the critical need of natural product-based antifoulants as a substitute for its toxic counterparts. In this study, the antibacterial and antibiofilm activities of the bioactive compounds of Pseudoalteromonas sp. IBRL PD4.8 have been investigated against selected fouling bacteria. The crude extract has shown strong antibacterial activity against five fouling bacteria, with inhibition zones ranging from 9.8 to 13.7 mm and minimal inhibitory concentrations of 0.13 to 8.0 mg/ml. Meanwhile, the antibiofilm study has indicated that the extract has attenuated the initial and pre-formed biofilms of Vibrio alginolyticus FB3 by 45.37 ± 4.88% and 29.85 ± 2.56%, respectively. Moreover, micrographs from light and scanning electron microscope have revealed extensive structural damages on the treated biofilms. The active fraction was fractionated with chromatographic methods and liquid chromatography-mass spectroscopy analyses has further disclosed the presence of a polyunsaturated fatty acid 4,7,10,13-hexadecatetraenoic acid (C16H24O2). Therefore, this compound was suggested as a potential bioactive compound contributing to the antibacterial property. In conclusion, Pseudoalteromonas sp. IBRL PD4.8 is a promising source as a natural antifouling agent that can suppress the growth of five fouling bacteria and biofilms of V. alginolyticus FB3. Biofouling is a phenomenon that describes the fouling organisms attached to man-made surfaces immersed in water over a period of time. It has emerged as a chronic problem to the oceanic industries, especially the shipping and aquaculture fields. The metal-containing coatings that have been used for many years to prevent and destroy biofouling are damaging to the ocean and many organisms. Therefore, this calls for the critical need of natural product-based antifoulants as a substitute for its toxic counterparts. In this study, the antibacterial and antibiofilm activities of the bioactive compounds of Pseudoalteromonas sp. IBRL PD4.8 have been investigated against selected fouling bacteria. The crude extract has shown strong antibacterial activity against five fouling bacteria, with inhibition zones ranging from 9.8 to 13.7 mm and minimal inhibitory concentrations of 0.13 to 8.0 mg/ml. Meanwhile, the antibiofilm study has indicated that the extract has attenuated the initial and pre-formed biofilms of Vibrio alginolyticus FB3 by 45.37 ± 4.88% and 29.85 ± 2.56%, respectively. Moreover, micrographs from light and scanning electron microscope have revealed extensive structural damages on the treated biofilms. The active fraction was fractionated with chromatographic methods and liquid chromatography-mass spectroscopy analyses has further disclosed the presence of a polyunsaturated fatty acid 4,7,10,13-hexadecatetraenoic acid (C16H24O2). Therefore, this compound was suggested as a potential bioactive compound contributing to the antibacterial property. In conclusion, Pseudoalteromonas sp. IBRL PD4.8 is a promising source as a natural antifouling agent that can suppress the growth of five fouling bacteria and biofilms of V. alginolyticus FB3.

Although commonly regarded as human and animal intestinal tract commensals, Enterococcus spp. have emerged as important nosocomial pathogens due to their intrinsic or acquired resistance to a number of antibiotics. Poultry has been suggested to be a reservoir for antibiotic resistance that may aggravate the problem of transmission of enterococci infections. Between January and December 2016, 106 Enterococcus spp. were isolated from a total of three poultry species. The collection included isolates recovered from chickens (n = 30), ducks (n = 35) and pigeons (n = 41). All enterococci isolates were screened for their ability to form biofilm. The antibiotic susceptibility was determined against 13 antibiotics using the disc diffusion method. The presence of the eight resistance genes, vanA, vanB, vanC, catA, catB, fexA, fexB and cfr was determined by PCR. All 106 isolates were resistant to clindamycin, whereas majority of isolates (>90%) were resistant to erythromycin, oxytetracycline, doxycycline, gentamycin, ciprofloxacin, norfloxacin, and vancomycin. All isolates produced biofilms and were classified as extensive drug-resistant. MARindices for all isolates was determined to be > 0.8, indicating that they have been recovered from high risk contamination sources. The cfr resistance gene was not detected in any of the 106 enterococci isolates, whereas the chloramphenicol resistance genes catA and catB were found in 18.9% (20/106) of the isolates. Interestengly, fexA 11.9% (15/106), fexB 8.7% (11/106), vanA 18.9% (20/106), vanB 25.5% (27/106), and vanC 33% (35/106) genes were also determined in our study. The present study highlights the emergence of a linezolid sensitive-vancomycin resistant enterococci, which lacks the cfr gene reporting also for the first time the detection of van, fex and cat -genes in Enterococcus species recovered from chickens, ducks and pigeons in Egypt suggesting that poultry species could be potential vectors for transmission of multidrug resistant enterococci posing a public health risk.

This study aimed to investigate the antimicrobial susceptibility of Shigella isolated in Shanghai, China and to determine the genetic basis of its resistance to fluoroquinolones.A total of 402 strains of Shigella, including 145 Shigella flexneri and 257 Shigella sonnei isolates, were analyzed. The Kirby-Bauer disk diffusion method was used to determine the susceptibility of the strains to 13 antimicrobials. Minimum inhibitory concentration of ciprofloxacin was determined by E-test. Mutations within the quinolone resistance-determining regions (QRDRs) of gyrA and parC and in the plasmid-mediated quinolone resistance (PMQR) genes, including qnrA, qnrB, qnrS, and aac (6')-Ib-cr, were detected by polymerase chain reaction. All the products were then sequenced.Most of the Shigella isolates were found to be resistant to nalidixic acid (96.4%), streptomycin (96.4%), ampicillin (86.2%), tetracycline (79.8%), and sulfamethoxazole/trimethoprim (80.6%). S. flexneri isolates showed a significantly higher resistance to cefepime (33.6%), ciprofloxacin (54.2%), norfloxacin (34.1%), and levofloxacin (12.1%) compared with that observed for the S. sonnei strains (χThe mutation percentage within the QRDR of S. flexneri was as high as 98.6 in gyrA and 97.9 in parC. The significant abundance of mutations within QRDRs conferred high levels of fluoroquinolone resistance. Moreover, the PMQR genes, particularly qnrS, played an important role in the decreased susceptibility of Shigella to fluoroquinolones.

Between September 2013 and March 2016, 26 (1.95 %) of 1333 Staphylococcus aureus clinical isolates from a Chinese hospital were found to be resistant to mupirocin, including 18 (1.35 %) with high-level mupirocin resistance and 8 (0.6 %) with low-level mupirocin resistance. Among the 18 isolates with high-level mupirocin resistance, 17 were associated with plasmid-mediated mupA. Meanwhile, the 8 isolates with low-level mupirocin resistance were shown to have a V588F mutation in ileS. A total of 14 sequence types (STs) and 18 spa types were identified. All four isolates with t062 belonged to ST965. Three ST5-MRSA-SCCmec II were linked to t311, which was not previously reported. Furthermore, ST764-MRSA-SCCmec II-t002, exclusively found in Japan before, was identified in this study. In conclusion, we observed relatively low prevalence of mupirocin resistance among S. aureus with considerable heterogeneity in East China. Newly emerging MRSA clones with high-level mupirocin resistance should be of concern.