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1.
PLoS One ; 18(6): e0287800, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37352213

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0247655.].

2.
Microb Drug Resist ; 28(4): 492-497, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35180355

RESUMO

Global dissemination of mobilized colistin resistance (mcr)-1-carrying plasmids has been reported. This study aimed to investigate the global dissemination of these plasmids using whole genome sequencing to provide better understanding on genetic characteristics. Sixty-seven complete plasmid genomes harboring mcr-1 were obtained. Phylogeny was built against full plasmid genomes. Different replicon types of plasmid were compared in terms of antimicrobial resistance genes (ARGs), insertion sequence, and other functional genes. Five different replicon types of plasmid (IncX4, IncI2, IncP1, IncHIA, and IncFIB) were found to harbor mcr-1. IncX4 and IncI2 types of plasmid were well clustered in accordance with the country where they were isolated (and not as IncHIA and IncFIB). Three insertion sequences (ISApl1, ISKpn26, and IS1294) were identified in up- and/or downstream of mcr-1. Plasmids IncX4 and IncI2 were observed across the sample origin. Plasmids IncX4 showed high uniformity regardless of the origin of isolates and harbored H-NS coding genes, a facilitator for successful plasmid transfer. All three insertion sequences were observed in IncI2 plasmids. IncHI2 plasmids harbored various ARGs in addition to mcr-1. Our results elucidate the characteristics and phylogenetic relationships of complete mcr-1-harboring plasmids, indicating that global dissemination of mcr-1 is primarily owing to plasmid transfer rather than clonal spread.


Assuntos
Colistina , Proteínas de Escherichia coli , Antibacterianos/farmacologia , Colistina/farmacologia , Elementos de DNA Transponíveis/genética , Farmacorresistência Bacteriana/genética , Enterobacteriaceae , Escherichia coli , Proteínas de Escherichia coli/genética , Filogenia , Plasmídeos/genética
3.
Front Vet Sci ; 8: 650866, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34026890

RESUMO

Feline parvovirus (FPV) is a small, non-enveloped, single-stranded DNA virus that infects cats. We recently isolated a feline parvovirus Fe-P2 strain from a dead stray cat in Iksan, 2017. Its partial genomic sequence (4,643 bases) was obtained, and phylogenetic analysis based on the VP2 nucleotide sequence showed that the FPV Fe-P2 strain was closely related to the FPV isolate Gigucheon in cat, 2017 (MN400978). In addition, we performed a serum neutralization (SN) test with the FPV isolates in various mammalian sera. These were from raccoon dog, water deer, Eurasian otter, Korean hare, leopard cat, and Asian badger, which were kindly provided by Chungnam Wild Animal Rescue Center. Notably, serological evidence of its infection was found in Asian badger, Meles leucurus (2/2) and leopard cat, Prionailurus bengalensis (5/8) through SN tests, whereas there was no evidence in raccoon dog, water deer, Eurasian otter, and Korean hare based on the collected sera in this study. These findings might provide partial evidence for the possible circulation of FPV or its related viruses among wild leopard cat and Asian badger in Korea. There should be additional study to confirm this through direct detection of FPVs in the related animal samples.

4.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34001598

RESUMO

Collective intelligence (CI) is critical to solving many scientific, business, and other problems, but groups often fail to achieve it. Here, we analyze data on group performance from 22 studies, including 5,279 individuals in 1,356 groups. Our results support the conclusion that a robust CI factor characterizes a group's ability to work together across a diverse set of tasks. We further show that CI is predicted by the proportion of women in the group, mediated by average social perceptiveness of group members, and that it predicts performance on various out-of-sample criterion tasks. We also find that, overall, group collaboration process is more important in predicting CI than the skill of individual members.


Assuntos
Inteligência/fisiologia , Eventos de Massa , Percepção Social/psicologia , Adolescente , Adulto , Idoso , Feminino , Processos Grupais , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
5.
PLoS One ; 16(3): e0247655, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735258

RESUMO

Collective intelligence (CI) is the ability of a group to solve a wide range of problems. Synchrony in nonverbal cues is critically important to the development of CI; however, extant findings are mostly based on studies conducted face-to-face. Given how much collaboration takes place via the internet, does nonverbal synchrony still matter and can it be achieved when collaborators are physically separated? Here, we hypothesize and test the effect of nonverbal synchrony on CI that develops through visual and audio cues in physically-separated teammates. We show that, contrary to popular belief, the presence of visual cues surprisingly has no effect on CI; furthermore, teams without visual cues are more successful in synchronizing their vocal cues and speaking turns, and when they do so, they have higher CI. Our findings show that nonverbal synchrony is important in distributed collaboration and call into question the necessity of video support.


Assuntos
Processos Grupais , Inteligência , Percepção Social/psicologia , Fala/fisiologia , Adolescente , Adulto , Sinais (Psicologia) , Expressão Facial , Feminino , Humanos , Internet , Masculino , Projetos de Pesquisa , Comunicação por Videoconferência/organização & administração
6.
Food Sci Biotechnol ; 29(10): 1433-1438, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32999751

RESUMO

This study aimed to investigate the influence of sodium reduction and storage temperature on the growth of total microbes and Bacillus cereus in naturally contaminated hamburger patty and loaf bread, respectively. The sodium reduction rate of hamburger patty and loaf bread was 20% and 30%, respectively, and experimental samples were kept at 4 °C, 25 °C, and 40 °C for 60 h. The microbiological analysis included the colony count of total microbes and B. cereus. The water activity (Aw), titratable acidity (TA), and pH were assessed as factors that inhibit microbial growth. In this study, Aw, TA, and pH of all samples were affected by the growth of total microbes and B. cereus during the storage period. Hence, these results suggested that sodium reduction in processed foods should be preferentially applied as a potent inhibition strategy after accurate assessment of inhibitors for different food types.

7.
J Clin Neurol ; 16(2): 261-269, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32319243

RESUMO

BACKGROUND AND PURPOSE: The first-line medications for the symptomatic treatment of rapid eye movement sleep behavior disorder (RBD) are clonazepam and melatonin taken at bedtime. We aimed to identify the association between depression and treatment response in patients with idiopathic RBD (iRBD). METHODS: We reviewed the medical records of 123 consecutive patients (76 males; age, 66.0±7.7 years; and symptom duration, 4.1±4.0 years) with iRBD who were treated with clonazepam and/or melatonin. Clonazepam and melatonin were initially administered at 0.25-0.50 and 2 mg/day, respectively, at bedtime, and the doses were subsequently titrated according to the response of individual patients. Treatment response was defined according to the presence or absence of any improvement in dream-enacting behaviors or unpleasant dreams after treatment. RESULTS: Forty (32.5%) patients were treated with clonazepam, 56 (45.5%) with melatonin, and 27 (22.0%) with combination therapy. The doses of clonazepam and melatonin at followup were 0.5±0.3 and 2.3±0.7 mg, respectively. Ninety-six (78.0%) patients reported improvement in their RBD symptoms during a mean follow-up period of 17.7 months. After adjusting for potential confounders, depression was significantly associated with a negative treatment response (odds ratio=3.76, 95% confidence interval=1.15-12.32, p=0.029). CONCLUSIONS: We found that comorbid depression is significantly associated with a negative response to clonazepam and/or melatonin in patients with iRBD. Further research with larger numbers of patients is needed to verify our observations and to determine the clinical implications of comorbid depression in the pathophysiology of iRBD.

8.
Microbiol Resour Announc ; 9(7)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054707

RESUMO

Cases of human infection with a swine influenza A virus variant have been reported in the United States, and since 2011, H3N2 variant viruses have also been regularly isolated from swine in the Republic of Korea. Here, we genetically characterized an influenza A H3N2 isolate (A/swine/P17-4/2017). BLASTN analysis of the 8 gene sequences revealed a high degree of nucleotide similarity (97.0 to 99.0%) to porcine strains circulating in the Republic of Korea and the United States. Specifically, we found a high degree of similarity in the nucleotide matrix gene to those of recent isolates from North Carolina. Therefore, continuous epidemiological surveillance is necessary to monitor the variation and evolution of influenza A viruses.

9.
Front Psychol ; 10: 814, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31057455

RESUMO

Management of effort is one of the biggest challenges in any team, and is particularly difficult in distributed teams, where behavior is relatively invisible to teammates. Awareness systems, which provide real-time visual feedback about team members' behavior, may serve as an effective intervention tool for mitigating various sources of process-loss in teams, including team effort. However, most of the research on visualization tools has been focusing on team communication and learning, and their impact on team effort and consequently team performance has been hardly studied. Furthermore, this line of research has rarely addressed the way visualization tool may interact with team composition, while comprehension of this interaction may facilitate a conceptualization of more effective interventions. In this article we review the research on feedback in distributed teams and integrate it with the research on awareness systems. Focusing on team effort, we examine the effect of an effort visualization tool on team performance in 72 geographically distributed virtual project teams. In addition, we test the moderating effect of team composition, specifically team members' conscientiousness, on the effectiveness of the effort visualization tool. Our findings demonstrate that the effort visualization tool increases team effort and improves the performance in teams with a low proportion of highly conscientious members, but not in teams with a high proportion of highly conscientious members. We discuss the theoretical and practical implications of our findings, and suggest the need of future research to address the way technological advances may contribute to management and research of team processes.

10.
Clin Pharmacol ; 11: 51-56, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30936756

RESUMO

PURPOSE: The purpose of this study was to investigate the effects of the type of formulation on the efficacy of warfarin. MATERIALS AND METHODS: The electronic medical records of patients with cerebral infarction, who were administered tablet or powder formulations of warfarin from 2013-2015, were retrospectively analyzed. Clinical data, changes in the international normalized ratio (INR), the warfarin dose, and the time to reach the plasma warfarin concentration that could induce an adverse effect, such as bleeding, were evaluated. Coefficients of variation of INR and of the warfarin dose, as well as the warfarin sensitivity index (WSI), were used to evaluate the INR stability. Statistical analysis of the data was performed using a independent t-test. Additionally, survival analysis was performed. RESULTS: The data showed that 57 and 137 patients were administered warfarin as powder and tablet formulations, respectively. We noted that INR, WSI, and INR/dose × body weight differed significantly between the two groups of patients. The median survival times to reach the plasma warfarin concentration that could induce adverse effects were 3.6 and 4.2 days of treatment with the powder and tablet formulations, respectively. The efficacy of warfarin was higher when the drug was administered as a powder than when it was administered as a tablet. CONCLUSION: The findings of this study indicate that INR should be carefully monitored in the first 4 days of warfarin administration as a powder formulation.

11.
J Food Sci ; 84(1): 133-137, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30557913

RESUMO

The presence of unwanted competing flora has been the most common confounding factor in the enumeration of Bacillus cereus (B. cereus) using selective media such as mannitol-yolk-polymyxin B agar (MYPA). The objective of this study was to improve MYPA selectivity for B. cereus by supplementation with a second-generation cephalosporin, cefuroxime. The performance of cefuroxime-supplemented MYPA (cefu-MYPA) was evaluated by comparison with original MYPA in 60 food products with established microbiological standards for B. cereus contamination. Cefu-MYPA demonstrated superior recoverability and selectivity for B. cereus compared with original MYPA in most tested foods. B. cereus numbers on MYPA and cefu-MYPA were 363.5 and 462.0 CFU/g, respectively. Competing flora on cefu-MYPA was detected in significantly less samples (70%) compared to original MYPA (93%). In addition, the detection and isolation of suspected colonies were significantly improved in cefu-MYPA because of the reduction or elimination of competing flora in all tested foods except fruit juice, indicating superior selectivity of the modified medium. Our findings suggest that cefuroxime supplementation of MYPA would markedly improve the detection rate of B. cereus, particularly in foods with high levels of indigenous flora.


Assuntos
Bacillus cereus/isolamento & purificação , Cefuroxima/química , Meios de Cultura/química , Gema de Ovo/química , Contaminação de Alimentos/análise , Manitol/química , Ágar/química , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Polimixina B/química
12.
PLoS One ; 13(10): e0204547, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30304044

RESUMO

Today, many complex tasks are assigned to teams, rather than individuals. One reason for teaming up is expansion of the skill coverage of each individual to the joint team skill set. However, numerous empirical studies of human groups suggest that the performance of equally skilled teams can widely differ. Two natural question arise: What are the factors defining team performance? and How can we best predict the performance of a given team on a specific task? While the team members' task-related capabilities constrain the potential for the team's success, the key to understanding team performance is in the analysis of the team process, encompassing the behaviors of the team members during task completion. In this study, we extend the existing body of research on team process and prediction models of team performance. Specifically, we analyze the dynamics of historical team performance over a series of tasks as well as the fine-grained patterns of collaboration between team members, and formally connect these dynamics to the team performance in the predictive models. Our major qualitative finding is that higher performing teams have well-connected collaboration networks-as indicated by the topological and spectral properties of the latter-which are more robust to perturbations, and where network processes spread more efficiently. Our major quantitative finding is that our predictive models deliver accurate team performance predictions-with a prediction error of 15-25%-on a variety of simple tasks, outperforming baseline models that do not capture the micro-level dynamics of team member behaviors. We also show how to use our models in an application, for optimal online planning of workload distribution in an organization. Our findings emphasize the importance of studying the dynamics of team collaboration as the major driver of high performance in teams.


Assuntos
Comportamento Cooperativo , Processos Grupais , Modelos Psicológicos , Humanos , Processos Mentais , Análise de Regressão
13.
Nutrients ; 10(6)2018 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-29880741

RESUMO

We evaluate the accuracy of whole body muscle mass (WBMM) and appendicular skeletal muscle mass (ASMM) assessed by bioelectrical impedance analysis (BIA) using an InBody770 machine (InBody, Seoul, Korea) referenced to dual-energy X-ray absorptiometry (DXA) in 507 people (mean age 63.7 ± 10.8 years, body mass index (BMI) 25.2 ± 3.5 kg/m²). Mean WBMMs measured by BIA and DXA were 49.3 ± 6.6 kg and 46.8 ± 6.5 kg in men and 36.1 ± 4.7 kg and 34.0 ± 4.8 kg in women, respectively. The respective effect sizes and 95% confidence intervals (CIs) for the difference were 2.49 (2.22⁻2.76) for men, and 2.12 (1.91⁻2.33) for women. Mean ASMMs measured by BIA and DXA were 22.1 ± 3.3 kg and 19.9 ± 3.2 kg in men, and 15.3 ± 2.5 kg and 13.5 ± 2.2 kg in women, respectively. The respective effect sizes and 95% CIs for the difference were 2.26 (2.10⁻2.41) for men and 1.75 (1.65⁻1.87) for women. The BIA clearly overestimated WBMM by 2.28 kg and ASMM by 1.97 kg compared with DXA. Using BMI, gender, and fat percentage, we derive equations that improved the residuals to.


Assuntos
Absorciometria de Fóton , Composição Corporal , Músculo Esquelético/anatomia & histologia , Adiposidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Impedância Elétrica , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Análise Multivariada , Reprodutibilidade dos Testes , Fatores Sexuais , Adulto Jovem
14.
Anal Chim Acta ; 1029: 78-85, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-29907294

RESUMO

Campylobacter is the most common cause of infectious intestinal disease, with nearly all cases caused by two species: C. jejuni and C. coli. We recently reported a gold nanoparticle-based two-stage aptasensing platform, which was improved in the present study for the rapid and on-site detection of both C. jejuni and C. coli in food samples. Compared to the previous platform, the improved platform yielded a more obvious colour change from red to purple due to the aggregation of gold nanoparticles, and does not require additional time or a pH optimization step for the aptamers to be adsorbed onto the gold nanoparticles. Using a highly specific aptamer that binds to live C. jejuni and C. coli, the improved aptasensor was highly effective for testing pure culture samples. The accuracy of the newly developed platform was comparable (p = 0.688) to that of the gold-standard detection method of tazobactam-supplemented culture, whereas it was superior to the official agar-based detection method (p = 0.016) in a validation study with 50 naturally contaminated chicken carcass samples. This is the first study on a colorimetric sensor that targets both live C. coli and C. jejuni in naturally contaminated samples. In addition, we provide the first evidence that both morphological status and the amount of Campylobacter present play key roles in the effectiveness of colorimetric detection. Thus, suitable selection of an antibody or aptamer with consideration of the morphological status of pathogens in samples is essential for direct detection without enrichment. Our data suggest that the sensor developed in this study can provide an excellent screening method, with a reduction in the detection time from 48 h to 30 min after enrichment, thus saving time, labour, and cost.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/métodos , Campylobacter coli/isolamento & purificação , Campylobacter jejuni/isolamento & purificação , Galinhas/microbiologia , Colorimetria/métodos , Microbiologia de Alimentos , Animais , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Campylobacter coli/metabolismo , Campylobacter coli/fisiologia , Campylobacter jejuni/metabolismo , Campylobacter jejuni/fisiologia , Limite de Detecção , Nanopartículas Metálicas/química , Viabilidade Microbiana , Fatores de Tempo
15.
Int J Hyg Environ Health ; 221(2): 300-307, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29254843

RESUMO

Although the prevalence of community-acquired Stenotrophomonas maltophilia infections is sharply increasing, the sources and likely transmission routes of this bacterium are poorly understood. We studied the significance of the presence of S. maltophilia in final effluents and receiving rivers of pig farm wastewater treatment plants (WWTPs). The loads and antibiotic resistance profiles of S. maltophilia in final effluents were assessed. Antibiotic resistance determinants and biofilm formation genes were detected by PCR, and genetic similarity to clinical isolates was investigated using multilocus sequence typing (MLST). S. maltophilia was recovered from final effluents at two of three farms and one corresponding receiving river. Tests of resistance to antibiotics recommended for S. maltophilia infection revealed that for each agent, at least one isolate was classified as resistant or intermediate, with the exception of minocycline. Furthermore, multidrug resistant S. maltophilia susceptible to antibiotics of only two categories was isolated and found to carry the sul2 gene, conferring trimethoprim/sulfamethoxazole resistance. All isolates carried spgM, encoding a major factor in biofilm formation. MLST revealed that isolates of the same sequence type (ST; ST189) were present in both effluent and receiving river samples, and phylogenetic analysis showed that all of the STs identified in this study clustered with clinical isolates. Moreover, one isolate (ST192) recovered in this investigation demonstrated 99.61% sequence identity with a clinical isolate (ST98) associated with a fatal infection in South Korea. Thus, the pathogenicity of the isolates reported here is likely similar to that of those from clinical environments, and WWTPs may play a role as a source of S. maltophilia from which this bacterium spreads to human communities. To the best of our knowledge, this represents the first report of S. maltophilia in pig farm WWTPs. Our results indicate that nationwide epidemiological investigations are needed to examine the possible link between WWTP-derived S. maltophilia and hospital- and community-acquired infections.


Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Stenotrophomonas maltophilia/genética , Suínos , Águas Residuárias/microbiologia , Animais , Infecções Comunitárias Adquiridas/microbiologia , Farmacorresistência Bacteriana/genética , Fazendas , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Rios/microbiologia , Stenotrophomonas maltophilia/isolamento & purificação , Gerenciamento de Resíduos , Purificação da Água
16.
Poult Sci ; 97(1): 289-293, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29112760

RESUMO

Overgrowth of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (E. coli) on Campylobacter media prevents the latter's selective isolation, thereby making the improvement of Campylobacter-selective media necessary. We evaluated tazobactam (an ESBL inhibitor) to supplement Bolton enrichment broth (Tz-Bolton broth) for the selective isolation of Campylobacter in chicken carcass rinses. First, using 20 strains of ESBL-producing E. coli and 13 Campylobacter strains, we found 4 µg/mL of tazobactam to be optimal for inhibiting the ESBL-producing E. coli while allowing the growth of all tested Campylobacter strains. Next, 80 whole chicken carcasses were rinsed with buffered peptone water (BPW), and 25 mL of BPW rinse was mixed with 2 × blood-free Bolton broth (25 mL) with or without tazobactam followed by incubation at 42°C for 48 h under microaerobic conditions. A loopful of the incubated broth was inoculated on modified charcoal-cefoperazone-deoxycholate agar (mCCDA) and microaerobically incubated at 42°C for 48 h. The tazobactam supplemented Bolton broth showed a higher Campylobacter isolation rate (38.8%, p < 0.05) than normal Bolton broth (15%). Moreover, the number of mCCDA plates with non-Campylobacter was much lower (p < 0.05) after enrichment in Tz-Bolton broth (0%) than in the normal Bolton broth (80%), suggesting that selectivity of the modified broth was superior to normal Bolton broth.


Assuntos
Campylobacter/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Microbiologia de Alimentos/métodos , Carne/microbiologia , Ácido Penicilânico/análogos & derivados , Inibidores de beta-Lactamases/farmacologia , Animais , Técnicas Bacteriológicas/métodos , Galinhas/microbiologia , Meios de Cultura , Ácido Penicilânico/farmacologia , Tazobactam
17.
Ecotoxicol Environ Saf ; 149: 36-42, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29145163

RESUMO

Wastewater treatment plants (WWTPs) that release treated wastewater into the environment have emerged as a major threat to public health. In this study, we investigated Escherichia coli load and antibiotic-resistance profiles across different treatment processes at a swine farm WWTP. The frequency of the detection of class 1 and 2 integrons, and their association with antibiotic resistance, were also analyzed. Samples were obtained at each of five sampling sites that represented each processing step within the WWTP. The largest decrease in E. coli load was observed during the anaerobic digestion step (from 4.86 to 2.89log CFU/mL). Isolates resistant to ß-lactam antibiotics were efficiently removed after a series of treatment steps, whereas the proportions of isolates resistant to non-ß-lactam antibiotics and multidrug-resistant strains were maintained across treatments. The occurrence of integron-positive strains was not significantly different at the various sampling sites (43.4-70%; p>0.05). Of the class 1 integron-positive isolates, 17.9% harbored the integron-associated gene cassettes aadA2, aadA12, aadA22, and dfrA15. To the best of our knowledge, this is the first description of a class 1 integron containing the aadA12 gene cassette from a swine farm and the presence of a class 1 integron containing dfrA15 in E. coli. This suggests that novel antibiotic-resistance gene cassette arrays could be generated in swine farm WWTPs. Moreover, 75% of integron-positive strains were categorized as multidrug resistant, whereas only 15.4% of integron-negative strains were multidrug resistant (p<0.05), indicating that integrons may be responsible for mediating resistance in WWTPs. With regard to the occurrence of multidrug-resistant, integron-positive E. coli recovered from the final effluent, our results highlighted the potential risks associated with wastewater discharge from swine farm WWTPs in terms of the spread of antibiotic-resistant bacteria to the aquatic environment.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Integrons/genética , Águas Residuárias/química , Purificação da Água/métodos , Animais , Escherichia coli/genética , Fazendas , Suínos , Águas Residuárias/microbiologia
18.
J Food Sci ; 82(7): 1688-1692, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28621455

RESUMO

Exponential growth of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in Campylobacter media has become a common problem for the detection of Campylobacter in chicken meats. We investigated the minimum inhibitory concentration of 40 ESBL-producing E. coli isolates from meats obtained from various countries against antibacterial agents in Bolton broth (cefoperazone, vancomycin, and trimethoprim). All ESBL-producing E. coli strains were resistant to cefoperazone and vancomycin, whereas 50% of them were resistant to trimethoprim and grew in Bolton broth. We found that 20 µg/mL of rifampicin inhibited the growth of trimethoprim-resistant E. coli strains. Hence, we added 20 µg/mL of rifampicin to Bolton broth to improve the isolation of Campylobacter from chicken carcass rinses. The isolation rate of Campylobacter was significantly higher in the modified broth (44 out of 58, 75.9%, P < 0.05) than in the normal broth (0 out of 58, 0%). Furthermore, the number of agar plates with non-Campylobacter spp. was much lower after enrichment in the modified broth (4 out of 58, 6.9%, P < 0.05) than in the normal broth (58 out of 58, 100%).


Assuntos
Antibacterianos/farmacologia , Campylobacter/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Carne/microbiologia , Rifampina/farmacologia , beta-Lactamases/metabolismo , Animais , Campylobacter/genética , Galinhas/microbiologia , Meios de Cultura/metabolismo , Escherichia coli/enzimologia , Microbiologia de Alimentos
19.
J Food Prot ; 80(6): 1050-1053, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28513216

RESUMO

We investigated the efficacy of syringe filtration for selective isolation of Campylobacter from chicken carcass rinse by combining syringe filtration with the conventional culture method. Whole chicken carcass rinses were incubated in Bolton enrichment broth, set aside or subjected to syringe filtration, and streaked on Campy-Cefex agar with or without cefoperazone antibiotic supplement. Compared with the conventional method without filtration, 0.65-µm-pore-size syringe filtration resulted in a significantly higher number of Campylobacter-positive samples (23.8 to 37.5% versus 70.0 to 72.5%; P < 0.05), a lower number of plates contaminated with non-Campylobacter (93.8% versus 6.3 to 26.3%), and a lower growth index (1 = growth of a few colonies; 2 = growth of colonies on about half of the plate; and 3 = growth on most of the plate) for competing microbiota (2.9 to 3.0 versus 1.2 to 1.4). When syringe filtration was applied, agar plates containing the antibiotic had significantly less contamination (6.3% versus 26.3%; P < 0.05) and a lower growth index (1.2 versus 1.4) compared with plates without the antibiotic, although the Campylobacter isolation rate was similar (P > 0.05). Syringe filtration combined with conventional enrichment improved the rate and selectivity of Campylobacter isolation from chicken carcasses.


Assuntos
Campylobacter , Galinhas , Animais , Meios de Cultura , Microbiologia de Alimentos , Seringas
20.
Foodborne Pathog Dis ; 14(2): 84-88, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28051328

RESUMO

Culture-based detection of nontyphoidal Salmonella spp. in foods requires at least four working days; therefore, new detection methods that shorten the test time are needed. In this study, we developed a novel single-step Salmonella enrichment broth, SSE-1, and compared its detection capability with that of commercial single-step ONE broth-Salmonella (OBS) medium and a conventional two-step enrichment method using buffered peptone water and Rappaport-Vassiliadis soy broth (BPW-RVS). Minimally processed lettuce samples were artificially inoculated with low levels of healthy and cold-injured Salmonella Enteritidis (100 or 101 colony-forming unit/25 g), incubated in OBS, BPW-RVS, and SSE-1 broths, and streaked on xylose lysine deoxycholate (XLD) agar. Salmonella recoverability was significantly higher in BPW-RVS (79.2%) and SSE-1 (83.3%) compared to OBS (39.3%) (p < 0.05). Our data suggest that the SSE-1 single-step enrichment broth could completely replace two-step enrichment with reduced enrichment time from 48 to 24 h, performing better than commercial single-step enrichment medium in the conventional nonchromogenic Salmonella detection, thus saving time, labor, and cost.


Assuntos
Meios de Cultura/química , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Salmonella enteritidis/isolamento & purificação , Verduras/microbiologia , Contagem de Colônia Microbiana , Lactuca/microbiologia , Salmonella enteritidis/crescimento & desenvolvimento
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