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1.
AIDS ; 34(1): 91-101, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31634196

RESUMEN

OBJECTIVE: To analyze HIV drug resistance among MSM recruited for participation in the HPTN 078 study, which evaluated methods for achieving and maintaining viral suppression in HIV-infected MSM. METHODS: Individuals were recruited at four study sites in the United States (Atlanta, Georgia; Baltimore, Maryland; Birmingham, Alabama; and Boston, Massachusetts; 2016-2017). HIV genotyping was performed using samples collected at study screening or enrollment. HIV drug resistance was evaluated using the Stanford v8.7 algorithm. A multiassay algorithm was used to identify individuals with recent HIV infection. Clustering of HIV sequences was evaluated using phylogenetic methods. RESULTS: High-level HIV drug resistance was detected in 44 (31%) of 142 individuals (Atlanta: 21%, Baltimore: 29%, Birmingham: 53%, Boston: 26%); 12% had multiclass resistance, 16% had resistance to tenofovir or emtricitabine, and 8% had resistance to integrase strand transfer inhibitors (INSTIs); 3% had intermediate-level resistance to second-generation INSTIs. In a multivariate model, self-report of ever having been on antiretroviral therapy (ART) was associated with resistance (P = 0.005). One of six recently infected individuals had drug resistance. Phylogenetic analysis identified five clusters of study sequences; two clusters had shared resistance mutations. CONCLUSION: High prevalence of drug resistance was observed among MSM. Some had multiclass resistance, resistance to drugs used for preexposure prophylaxis (PrEP), and INSTI resistance. These findings highlight the need for improved HIV care in this high-risk population, identification of alternative regimens for PrEP, and inclusion of integrase resistance testing when selecting ART regimens for MSM in the United States.

2.
Sci Total Environ ; 700: 134446, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31648121

RESUMEN

Bacteriophage may play an important role in antimicrobial resistance genes (ARGs) transmission. However, the contribution of bacteriophage to the spread of ARGs in environment, especially in poultry farm environment, is rarely known. In this study, the prevalence of ARGs in bacteriophage DNA was investigated in chicken feces from 30 different poultry farms in China. Then the abundance of the aac(6')-Ib-cr, blaCTX-M, ermB, floR, mcr-1, sul1, tetM and intI1 genes was determined by qPCR in bacteriophage and compared with certain representative plasmid DNA samples. The results showed that 12 ARGs (aac(6')-Ib-cr, aph(3')-IIIa, blaCTX-M, ermB, ermF, floR, mcr-1, qnrS, sul1, sul2, vanA, tetM genes) and class 1 integron gene intI1 were detected in bacteriophage DNA fraction. The sul1, tetM and aac(6')-Ib-cr genes were most prevalent with high detection rates of 77%, 61% and 55%, respectively. To our best knowledge, this study firstly reported the presence of the mcr-1 gene in bacteriophage DNA derived from farms environments. We found that the gene copy (GC) numbers of the aac(6')-Ib-cr, ermB and sul1 genes were as high as 5.47, 5.22 and 5.54 log10 GC/g, respectively. Both the prevalence and abundance of ARGs in broiler fecal wastes were also generally higher than in laying hens. In addition, although the GC numbers of the aac(6')-Ib-cr, floR and tetM genes in plasmid DNA was higher than that in phage DNA fraction by 4.68, 3.59 and 3.9 orders of magnitude, respectively, the absolute abundances of the blaCTX-M and mcr-1 genes in phage DNA were close to or even higher than that in plasmid DNA at farm SIL2, SIL4 and SIB1. As potential vessels for ARGs, bacteriophage could not be ignored due to their unique extracellular persistence in environments. Overall, this is the first comprehensive survey about bacteriophage carried ARGs from farms in different regions in China.

3.
J Colloid Interface Sci ; 559: 313-323, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31675662

RESUMEN

Antibiotic resistance is a common phenomenon observed during treatment with antibacterials. Use of nanozymes, especially those with synergistic enzyme-like activities, as antibacterials could overcome this problem, but their synthesis is limited by their high cost and/or complex production process. Herein, vanadium oxide nanodots (VOxNDs) were prepared via a one-step bottom-up ethanol-thermal method using vanadium trichloride as the precursor. VOxNDs alone possess bienzyme mimics of peroxidase and oxidase. Accordingly, highly efficient antibacterials against drug-resistant bacteria can be obtained through synergistic catalysis; the oxidase-like activity decomposes O2 to generate superoxide anion radical (O2-) and hydroxyl radicals (OH), and the intrinsic peroxidase-like activity can further induce the production of OH from external H2O2. Consequently, H2O2 concentration could decrease up to four magnitude orders with VOxNDs to achieve an antibacterial efficacy similar to that of H2O2 alone. Wound healing in vivo further confirms the high antibacterial efficiency, good biocompatibility, and application potential of the synergistic antibacterial system due to the "nano" structure of VOxNDs. The method of synthesis of nanodot antibacterials described in this paper is inexpensive, and the results of this study reveal the multi-enzymatic synergism of nanozymes.

4.
Food Microbiol ; 85: 103295, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31500701

RESUMEN

Fermented red pepper (FRP) sauce has been eaten in worldwide for many years. The salt content and resident microbial community influences the quality of the FRP sauce and may confer health (e.g., probiotics) or harm (e.g., antibiotic resistance genes) to the consumers in some circumstances; however, the salt-mediated alteration of microbial community and antibiotic resistance genes are little known. In this study, a combination of whole genome sequencing and amplicon analysis was used to investigate the changes in microbial community and antimicrobial resistance genes in response to different salt content during red pepper fermentation. While the family Enterobacteriaceae dominated in high-salt (15-25%) samples, Lactobacillaceae quickly became the dominant population in place of Enterobacteriaceae after 24 days in 10% salt samples. Compared to 0.05 antibiotic resistance genes (ARGs) per cell number on average in 10% salt sample, 16.6 ARGs were present in high-salt samples, wherein the bacterial hosts were major assigned to Enterobacteriaceae including genera Enterobacter, Citrobacter, Escherichia, Salmonella and Klebsiella. Multidrug resistance genes were the predominant ARG type. Functional profiling showed that histidine kinase functions were of much higher abundance in high-salt samples and included several osmotic stress-related two-component systems that simultaneously encoded ARGs. These results give first metagenomic insights into the salt-mediated changes in microbial community composition and a broad view of associated antibiotic resistance genes in the process of food fermentation.

5.
Biomed Pharmacother ; 121: 109663, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31751870

RESUMEN

P-glycoprotein (P-gp) plays a significant role in multi-drug resistance (MDR) of cancer cells, resulting in the failure of cancer chemotherapy. Lathyrane diterpene was a class of promising MDR modulator. The phytochemical investigation on the seeds of Euphorbia lathyris L. aff ;orded four new lathyrol-type diterpenoids (1-4), together with seventeen known ones (5-23). The structures of these compounds were elucidated by using 1D and 2D NMR spectroscopy. All the compounds were evaluated reversing MDR activity in HepG2/ADR cells. Compounds 2-4, 7-9, 11, 13-14, 16, 18-19, and 2 1-2 3 at 20 µM was able to reverse MDR of HepG2/ADR cells to adriamycin (reversal fold: 10.05-448.39). In the investigation of reversing the MDR mechanism, the most potent compound 21 facilitated the accumulation of intracellular adriamycin in HepG2/ADR cells in the time-dependent model. Although 21 neither affected the P-gp distribution nor expression in HepG2/ADR cells, the amount of P-gp monomer was induced by 21 and verapamil. Compound 21 has also activated the P-gp coupled ATPase activity in a dose-dependent model. The molecular docking analysis implied that 21 had lower binding energy than verapamil and adriamycin. The present data demonstrated that lathyrane diterpenes may act as a class of high-affinity P-gp substrate and was effluxed by P-gp monomer to reverse the MDR.

7.
J Antibiot (Tokyo) ; 73(1): 72-75, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31586155

RESUMEN

A total of 24 non-antibiotic compounds were tested for their antimicrobial activity against Escherichia coli, Klebsiella pneumoniae (ATCC) and an MDR strain of Acinetobacter baumannii using an agar well diffusion assay. To study additive effects, 100 µl of each antibiotic and 50 µl of each non-antibiotic were used. Cloprostenol was the only non-antibiotic that showed antibacterial activity against all bacterial strains. Cloprostenol had an additive antimicrobial effect with the tested antibiotics against the MDR A. baumannii strain.

8.
Int J Hyg Environ Health ; 223(1): 151-158, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31648934

RESUMEN

The association of antimicrobial resistance (AMR) with climatic factors gained higher attention since resistance increased with increasing local temperatures in the USA. We aimed to investigate whether the explanatory strength of climatic factors holds true in a region encompassing diverse healthcare systems, like Europe. In particular, we determined whether exposure to temporal climate warming is associated with an increase in AMR prevalence for clinically relevant pathogens. A 30-country cross-sectional study was conducted. The six-year prevalence of carbapenem-resistant Pseudomonas aeruginosa (CRPA), Klebsiella pneumoniae (CRKP), Multiresistant Escherichia coli (MREC), and Methicillin-resistant Staphylococcus aureus (MRSA) was determined based on > 900 k clinical isolates. Bi- and multivariate analysis were performed to identify associations with climatic variables using healthcare and socio-economic confounders. CRPA was significantly associated with the warm-season change in temperature, which, alongside corruption perception, explained 78% of total CRPA variance. Accordingly, a 0.5 °C increase of year-wise temperature change (exposition) resulted in a 1.02-fold increase (p = 0.035) in CRPA prevalence (outcome). For a given country, exposition status doubled the odds of outcome attainment compared to non-exposition (OR = 2.03, 95%-CI [1.03-3.99]). Moreover, we found significant associations of CRKP, MREC, and MRSA with the warm-season mean temperature, which had a higher contribution to MRSA variance explanation than outpatient antimicrobial drug use. We identified a novel association between AMR and climatic factors in Europe, which reveals two aspects: climatic factors significantly contribute to the explanation of AMR in different types of healthcare systems, while climate change (i.e. warming) might increase AMR transmission, in particular CRPA.

9.
Int J Hyg Environ Health ; 223(1): 56-64, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31722832

RESUMEN

BACKGROUND: Point sources such as wastewater treatment plants (WWTPs) commonly discharge their effluent into rivers. Their waste may include antibiotic residues, disinfectants, antibiotic resistant bacteria (ARB), and Antimicrobial Resistance Genes (ARG). There is evidence that ARG can be found in the natural environment, but attribution to specific point sources is lacking. OBJECTIVES: The goal of this study was to assess the release and dissemination of ARG from three WWTPs in southern Chile via two pathways: through the river systems, and through wild birds. METHODS: A longitudinal study was conducted, collecting river sediment samples at different distances both upstream and downstream from each WWTP. Wild birds were sampled from around one of the WWTPs once a month for 13 months. A microfluidic q-PCR approach was used to quantify 48 genes covering different molecular mechanisms of resistance, and data was analyzed using ordination methods and linear mixed regression models. RESULTS: There was a statistically significant increase downstream from the WWTPs (p < 0.05) for 17 ARG, but the downstream dissemination through the rivers was not clear. Beta-lactamase genes blaKPC, blaTEM, and blaSHV were the most abundant in birds, with higher abundance of blaSHV in migratory species compared to resident species (p < 0.05). The gene profile was more similar between the migratory and resident bird groups compared to the WWTP gene profile. CONCLUSIONS: While results from this study indicate an influence of WWTPs on ARG abundance in the rivers, the biological significance of this increase and the extent of the WWTPs influence are unclear. In addition, wild birds were found to play a role in disseminating ARG, although association to the specific WWTP could not be ascertained.

10.
Mater Sci Eng C Mater Biol Appl ; 107: 110264, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31761183

RESUMEN

In vitro drug screening is widely used in the development of new drugs, because they constitute a cost-effective approach to select compounds with more potential for therapy. They are also an attractive alternative to in vivo testing. However, most of these assays are done in two-dimensional culture models, where cells are grown on a polystyrene or glass flat surface. In order to develop in vitro models that would more closely resemble physiological conditions, three-dimensional models have been developed. Here, we introduce two novel fully synthetic scaffolds produced using the polymer polyhydroxybutyrate (PHB): a Solvent-Casting Particle-Leaching (SCPL) membrane; and an electrospun membrane, to be used for 3D cultures of B16 F10 murine melanoma cells and 4T1 murine breast cancer cells. A 2D cell culture system in regular tissue culture plates and a classical 3D model where cells are grown on a commercially available gel derived from Engelbreth-Holm Swarm (EHS) tumor were used for comparison with the synthetic scaffolds. Cells were also collected from in vivo tumors grown as grafts in syngeneic mice. Morphology, cell viability, response to chemotherapy and gene expression analysis were used to compare all systems. In the electrospun membrane model, cells were grown on nanometer-scale fibers and in the SCPL membrane, which provides a foam-like structure for cell growth, pore sizes varied. Cells grown on all 3D models were able to form aggregates and spheroids, allowing for increased cell-cell contact when compared with the 2D system. Cell morphology was also more similar between 3D systems and cells collected from the in vivo tumors. Cells grown in 3D models showed an increase in resistance to dacarbazine, and cisplatin. Gene expression analysis also revealed similarities among all 3D platforms. The similarities between the two synthetic systems to the classic EHS gel model highlight their potential application as cost effective substitutes in drug screening, in which fully synthetic models could represent a step towards higher reproducibility. We conclude PHB synthetic membranes offer a valuable alternative for 3D cultures.

11.
J Hazard Mater ; 382: 121266, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31563808

RESUMEN

Probiotic microbes conferring health benefits to the hosts have attracted great attention. However, the safety of probiotics is not guaranteed, although the increasing widespread use of probiotics with excellent overall safety records. Here, we performed a systematic evaluation of the safety of commercial Bacillus probiotics intended for usage in humans, animals, plants, aquaculture and environment in China. Nearly half of the 65 isolated Bacillus spp. strains from these commercial probiotic products were capable of producing hazardous toxins. Infections with the representative isolates could cause sepsis, intestinal inflammation and liver injury in different mouse models. Additionally, these isolates harbor multiple antimicrobial resistance genes coupled with mobile genetic elements. Collectively, the capability for producing various toxins and harboring mobile antimicrobial resistance genes in Bacillus probiotics indicates a potential risk for One Health.

12.
Ann Lab Med ; 40(2): 142-147, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31650730

RESUMEN

BACKGROUND: Although the incidence of tuberculosis (TB) is decreasing, cases of multidrug-resistant (MDR) TB and extensively drug-resistant (XDR) TB continue to increase. As conventional phenotype drug susceptibility testing (pDST) takes six to eight weeks, molecular assays are widely used to determine drug resistance. we developed QuantaMatrix Multiplexed Assay Platform (QMAP) MDR/XDR assay (QuantaMatrix Inc., Seoul, Korea) that can simultaneously detect mutations related to both first- and second-line drug resistance (rifampin, isoniazid, ethambutol, fluoroquinolones, second-line injectable drugs, and streptomycin). METHODS: We used 190 clinical Mycobacterium tuberculosis (MTB) strains isolated from Myanmar, compared QMAP and pDST results, and determined concordance rates. Additionally, we performed sequence analyses for discordant results. RESULTS: QMAP results were 87.9% (167/190) concordant with pDST results. In the 23 isolates with discordant results, the QMAP and DNA sequencing results completely matched. CONCLUSIONS: The QMAP MDR/XDR assay can detect all known DNA mutations associated with drug resistance for both MDR- and XDR-MTB strains. It can be used for molecular diagnosis of MDR- and XDR-TB to rapidly initiate appropriate anti-TB drug therapy.

13.
Eur J Pharm Sci ; 141: 105124, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31669761

RESUMEN

Influenza virus infections are a persistent threat to human health due to seasonal outbreaks and sporadic pandemics. Amantadine and rimantadine are FDA-approved influenza antiviral drugs and work by inhibiting the viral M2 proton channel. However, the therapeutic potential for the antiviral amantadine/rimantadine was curtailed by the emergence of drug-resistant mutations in its target protein M2. In this study, we identified four amantadine-resistant M2 mutants among avian and human influenza A H5N1 strains circulating between 2002 and 2019: the single S31N and V27A mutants, and the S31N/L26I and S31N/V27A double mutants. Herein, utilizing two-electrode voltage clamp (TEVC) assays, we screened a panel of structurally diverse M2 inhibitors against these single and double mutant channels. Three compounds 6, 7, and 15 were found to significantly block all three M2 mutants: M2-S31N, M2-S31N/L26I, and M2-S31N/V27A. Using recombinant viruses generated from reverse genetics, we further showed that these compounds also inhibited the replication of recombinant viruses harboring either the single S31N or double S31N/L26I and S31N/V27A mutants. This work represents the first example in developing antivirals by targeting the drug-resistant double mutants of M2 proton channels.

14.
Clin Pediatr (Phila) ; 59(1): 31-33, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31603009

RESUMEN

Enteric fever (formerly typhoid fever) is a bacterial illness caused by fecal-oral transmission of Salmonella typhi or paratyphi. In early 2018, an outbreak of Salmonella typhi resistant to third-generation cephalosporins, ampicillin, ciprofloxacin, trimethroprim-sulfamethoxazole, and chloramphenicol was reported in Pakistan. This strain, termed "extensively resistant typhi," has infected more than 5000 patients in endemic areas of South Asia, as well as travelers to and from these areas, including 5 cases in the United States. We present the case of one such child who developed extensively resistant enteric fever during a recent visit to Pakistan and required broader antimicrobial treatment than typically required. Clinicians should be aware that incoming cases of enteric fever may be nonsusceptible to commonly recommended antibiotics and that extensively resistant typhi requires treatment with carbapenems such as meropenem or azithromycin.

15.
Drug Resist Updat ; 48: 100663, 2019 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-31785545

RESUMEN

Drug resistance is a major obstacle in the field of pre-clinical and clinical therapeutics. The development of novel technologies and targeted therapies have yielded new modalities to overcome drug resistance, but multidrug resistance (MDR) remains one of the major challenges in the treatment of cancer. The ubiquitin-proteasome system (UPS) has a central role in regulating the levels and activities of a multitude of proteins as well as regulation of cell cycle, gene expression, response to oxidative stress, cell survival, cell proliferation and apoptosis. Therefore, inhibition of the UPS could represent a novel strategy for the treatment and overcoming of drug resistance in chemoresistant malignancies. In 2003, bortezomib was approved by the FDA for the treatment of multiple myeloma (MM). However, due to its limitations, second generation proteasome inhibitors (PIs) like carfilzomib, ixazomib, oprozomib, delanzomib and marizomib were introduced which displayed clinical activity in bortezomib-resistant tumors. Past studies have demonstrated that proteasome inhibition potentiates the anti-cancer efficacy of other chemotherapeutic drugs by: i) decreasing the expression of anti-apoptotic proteins such as TNF-α and NF-kB, ii) increasing the levels of Noxa, a pro-apoptotic protein, iii) activating caspases and inducing apoptosis, iv) degrading the pro-survival protein, induced myeloid leukemia cell differentiation protein (MCL1), and v) inhibiting drug efflux transporters. In addition, the mechanism of action of the immunoproteasome inhibitors, ONX-0914 and LU-102, suggested their therapeutic role in the combination treatment with PIs. In the current review, we discuss various PIs and their underlying mechanisms in surmounting anti-tumor drug resistance when used in combination with conventional chemotherapeutic agents.

16.
Brain Res ; : 146558, 2019 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-31794706

RESUMEN

BACKGROUND AND PURPOSE: Epilepsy is one of the most common diseases of the nervous system. Approximately one-third of epilepsy cases are drug-resistant, among which generalized-onset seizures are very common. The present study aimed to analyze abnormalities of the thalamocortical fiber pathways in each hemisphere of the brains of patients with drug-resistant generalized epilepsy. MATERIALS AND METHODS: The thalamocortical structural pathways were identified by diffusion tensor imaging (DTI) in 15 patients with drug-resistant generalized epilepsy and 16 gender/age-matched controls. The thalami of both groups were parcellated into subregions according to the local thalamocortical connectivity pattern. DTI measures of thalamocortical connections were compared between the two groups. RESULTS: Probabilistic tractography analyses showed that fractional anisotropy of thalamocortical pathways in patients with epilepsy decreased significantly, and the radial diffusivity of the left thalamus pathways with homolateral motor and parietal-occipital cortical regions in the drug-resistant epilepsy group increased significantly. In addition to the right thalamus pathway and prefrontal cortical region, fractional anisotropy of all other pathways was inversely correlated with disease duration. CONCLUSION: The results provide evidence indicating widespread bilateral abnormalities in the thalamocortical pathways in epilepsy patients and imply that the degree of abnormality in the pathway increases with the disease duration.

17.
PLoS Negl Trop Dis ; 13(12): e0007917, 2019 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-31790418

RESUMEN

BACKGROUND: Limited epidemiological and antimicrobial resistance data are available on Salmonella enterica from sub-Saharan Africa. We determine the prevalence of resistance to antibiotics in isolates in the Central African Republic (CAR) between 2004 and 2013 and the genetic basis for resistance to third-generation cephalosporin (C3G). METHODOLOGY/PRINCIPAL FINDINGS: A total of 582 non-duplicate human clinical isolates were collected. The most common serotype was Typhimurium (n = 180, 31% of the isolates). A randomly selected subset of S. Typhimurium isolates were subtyped by clustered regularly interspaced short palindromic repeat polymorphism (CRISPOL) typing. All but one invasive isolate tested (66/68, 96%) were associated with sequence type 313. Overall, the rates of resistance were high to traditional first-line drugs (18-40%) but low to many other antimicrobials, including fluoroquinolones (one resistant isolate) and C3G (only one ESBL-producing isolate). The extended-spectrum beta-lactamase (ESBL)-producing isolate and three additional ESBL isolates from West Africa were studied by whole genome sequencing. The blaCTX-M-15 gene and the majority of antimicrobial resistance genes found in the ESBL isolate were present in a large conjugative IncHI2 plasmid highly similar (> 99% nucleotide identity) to ESBL-carrying plasmids found in Kenya (S. Typhimurium ST313) and also in West Africa (serotypes Grumpensis, Havana, Telelkebir and Typhimurium). CONCLUSIONS/SIGNIFICANCE: Although the prevalence of ESBL-producing Salmonella isolates was low in CAR, we found that a single IncHI2 plasmid-carrying blaCTX-M-15 was widespread among Salmonella serotypes from sub-Saharan Africa, which is of concern.

18.
Res Vet Sci ; 128: 135-144, 2019 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-31785428

RESUMEN

Swine respiratory disease complex (SRDC) causes massive economic losses to the swine industry and is a major animal welfare concern. Antimicrobials are mainstay in treatment and control of SRDC. However, there is a lack of data on the prevalence and trends in resistance to antimicrobials in bacterial pathogens associated with SRDC. The objective of this study was to estimate the prevalence and changes in resistance to 13 antimicrobials in swine bacterial pathogens (Streptococcus suis, Pasteurella multocida, Actinobacillus suis and Haemophilus parasuis) in the U.S.A using data collected at University of Minnesota Veterinary Diagnostic Laboratory between 2006 and 2016. For antimicrobials for which breakpoints were available, prevalence of resistance remained below 10% except for tetracycline in S. suis and P. multocida isolates, and these prevalence estimates remained consistently low over the years despite statistical significance (p < .05) in trend analysis. For antimicrobial-bacterial combinations without available breakpoints, the odds of isolates being resistant increased by >10% annually for 7 and 1 antimicrobials in H. parasuis and S. suis isolates respectively, and decreased >10% annually for 4 and 1 antimicrobials in A. suis and H. parasuis isolates, respectively, according to the ordinal regression models. Clinical implications of changes in AMR for A. suis and H. parasuis should be interpreted cautiously due to the lack of interpretive criteria and challenges in antimicrobial susceptibility tests in the case of H. parasuis. Future studies should focus on surveillance of antimicrobial resistance and establishment of standardized susceptibility testing methodologies and interpretive criteria for these animal pathogens of critical importance.

19.
Int J Food Microbiol ; 317: 108461, 2019 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-31794931

RESUMEN

Vibrio parahaemolyticus is the leading cause of foodborne bacterial poisoning in China. The aim of this research is to conduct a study on the prevalence, virulence, and antimicrobial resistance of V. parahaemolyticus from different types of food samples in 12 different cities of China. Since fluoroquinolones are the major choice of treatment for V. parahaemolyticus infections, the genetic basis for fluoroquinolone resistance in V. parahaemolyticus were also investigated. V. parahaemolyticus was detected in 163 of the 784 food samples collected from 12 different cities in China, resulting in a prevalence of 20.79%. The prevalence of V. parahaemolyticus in ready-to-eat (RTE) food (4.96%) was much lower than those of shrimp (32.62%) and fish (22.00%). Virulence gene screening showed that 44 (27.00%) V. parahaemolyticus strains carried at least one virulence gene. Four isolates from shrimp and three isolates from fish contained both the virulence genes tdh and trh. In addition, the trh was firstly detected in one isolate collected from RTE food. All isolates exhibited relatively high resistance rates to ampicillin (82.21%), gentamicin (19.63%), and tetracycline (14.11%), while <10% of strains were resistant to ciprofloxacin (4.91%), levofloxacin (4.91%), and tetracycline (4.29%). Eight fluoroquinolone-resistant V. parahaemolyticus were selected to determine the molecular basis for fluoroquinolone resistance. These eight isolates belonged to three different types according to enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR). A Ser83Ile substitution in GyrA was deteted in seven fluoroquinolone-resistant strains, except V209 which harbored a Ser83Phe substitution in GyrA. Moreover, A Ser85Leu substitution in ParC was found in five isolates (V52, V53, V61, V163, and V209). Plasmid-mediated quinolone resistance (PMQR) genes were detected in all eight fluoroquinolone-resistant V. parahaemolyticus strains. This is the first report of Ser83Phe substitution in GyrA, qnrD and qnrS1 in V. parahaemolyticus. The information generated in this study will provide valuable information for risk assessment of V. parahaemolyticus infections and future control of antibiotic-resistant V. parahaemolyticus species in China.

20.
Artículo en Inglés | MEDLINE | ID: mdl-31800331

RESUMEN

Introduction: Antimicrobial resistance (AMR) played an important role in the initial outbreaks of Clostridium difficile infection (CDI) in the 1970s. C. difficile ribotype (RT) 017 has emerged as the major strain of C. difficile in Asia, where antimicrobial use is poorly regulated. This strain has also caused CDI outbreaks around the world for almost 30 years. Many of these outbreaks were associated with clindamycin and fluoroquinolone resistance. AMR and selective pressure is likely to be responsible for the success of this RT and may drive future outbreaks.Areas covered: This narrative review summarizes the prevalence and mechanisms of AMR in C. difficile RT 017 and transmission of these AMR mechanisms. To address these topics, reports of outbreaks due to C. difficile RT 017, epidemiologic studies with antimicrobial susceptibility results, studies on resistance mechanisms found in C. difficile and related publications available through Pubmed until September 2019 were collated and the findings discussed.Expert opinion: Primary prevention is the key to control CDI. This should be achieved by developing antimicrobial stewardship in medical, veterinary and agricultural practices. AMR is the key factor that drives CDI outbreaks, and methods for the early detection of AMR can facilitate the control of outbreaks.

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