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1.
Nucleic Acids Res ; 48(4): 2013-2025, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-31930301

RESUMO

The rolling-circle replication is the most common mechanism for the replication of small plasmids carrying antibiotic resistance genes in Gram-positive bacteria. It is initiated by the binding and nicking of double-stranded origin of replication by a replication initiator protein (Rep). Duplex unwinding is then performed by the PcrA helicase, whose processivity is critically promoted by its interaction with Rep. How Rep and PcrA proteins interact to nick and unwind the duplex is not fully understood. Here, we have used magnetic tweezers to monitor PcrA helicase unwinding and its relationship with the nicking activity of Staphylococcus aureus plasmid pT181 initiator RepC. Our results indicate that PcrA is a highly processive helicase prone to stochastic pausing, resulting in average translocation rates of 30 bp s-1, while a typical velocity of 50 bp s-1 is found in the absence of pausing. Single-strand DNA binding protein did not affect PcrA translocation velocity but slightly increased its processivity. Analysis of the degree of DNA supercoiling required for RepC nicking, and the time between RepC nicking and DNA unwinding, suggests that RepC and PcrA form a protein complex on the DNA binding site before nicking. A comprehensive model that rationalizes these findings is presented.


Assuntos
Proteínas de Bactérias/genética , DNA Helicases/genética , Replicação do DNA/genética , Farmacorresistência Bacteriana/genética , Quebras de DNA de Cadeia Simples/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Geobacillus stearothermophilus/efeitos dos fármacos , Geobacillus stearothermophilus/genética , Geobacillus stearothermophilus/patogenicidade , Plasmídeos/efeitos dos fármacos , Plasmídeos/genética , Ligação Proteica/genética , Domínios e Motivos de Interação entre Proteínas/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Tetraciclina/farmacologia , Transativadores/genética
2.
J Dairy Sci ; 103(1): 840-845, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733844

RESUMO

This study investigated the antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) isolated from cases of subclinical bovine mastitis in China, as well as resistance mechanisms and virulence genes encoding adhesins and toxins. We determined antimicrobial susceptibility using the disk diffusion method, and analyzed resistance, adhesin, and toxin genes using PCR. We confirmed MRSA in 73 of 498 (14.7%) Staph. aureus isolates recovered from subclinical mastitic milk samples. All isolates were positive for mecA. The MRSA isolates showed high resistance to penicillin (100.0%), gentamicin (100.0%), and tetracycline (98.6%). All MRSA isolates harbored resistance genes blaZ (penicillin), aacA/aphD (gentamicin), and tetM (alone or in combination with tetK, tetracycline). Moreover, all isolates carried the adhesin genes fnbpA, clfA, clfB, cna, sdrE, and map/eap, and most carried sdrC (98.6%), sdrD (95.9%), bbp (94.5%), and ebpS (80.8%). The toxin genes seh, hla, and hld were present in all isolates, and most isolates carried sea (71.2%), seg (84.9%), sei (82.2%), lukE-lukD (97.3%), and hlg (72.6%). These findings of high-level resistance to antimicrobials commonly used in dairy cattle should lead to calls for antibiogram analysis before antimicrobial therapy. The high frequency of adhesin and toxin genes in MRSA indicates their potential virulence in bovine mastitis in China.


Assuntos
Mastite Bovina/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/veterinária , Adesinas Bacterianas/genética , Animais , Antibacterianos/farmacologia , Bovinos , China , Feminino , Gentamicinas/farmacologia , Mastite Bovina/tratamento farmacológico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase/veterinária , Infecções Estafilocócicas/microbiologia , Tetraciclina/farmacologia , Virulência/genética
3.
Ecotoxicol Environ Saf ; 188: 109910, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31740237

RESUMO

To alleviate the harmful effects of antibiotics on the environment and human health, the stress response and molecular network of Bacillus under tetracycline stress were investigated using a proteomics approach. During the exposure process, Bacillus subtilis exhibited a strong adaptation mechanism. Cell membrane and intracellular reactive oxygen species (ROS) level returned to normal after 5 h. A total of 312 upregulated and 65 downregulated proteins were identified, mainly involved in metabolism and the synthesis of ribosomes, DNA, and RNA. After tetracycline exposure, the core metabolism network was accelerated to supply precursors for the synthesis of DNA, RNA, proteins, peptidoglycans, and saturated fatty acids that were involved in ribosome protection, and strengthened the cell wall and cell membrane. The signal transduction pathways involved were analyzed in association with the stress response of B. subtilis at 15 min of exposure to tetracycline. The primary damage to the ribosome by tetracycline activated a series of response proteins. Antitoxin and heat-shock proteins were activated for the global regulation of transcription and metabolism. Trigger factor Tig was upregulated to ensure proper initiation of transcription and aerobic respiration. Temperature-sensor protein VicR from the two-component system was used by the cell to regulate the composition of the cell wall and cell membrane. The over-consumption of metabolites, such as phosphoribosyl diphosphate (PRPP), purine nucleoside triphosphate (GTP), and acetyl-CoA forced the cells to assimilate more sugar for glycolysis. To this end, methyl-accepting chemotaxis proteins (MCPs) and sugar transportation protein PtsG were upregulated, simultaneously. Ultimately, peroxidase was activated to eliminate the redundant ROS, to minimize cell damage. These findings presented a system-level understanding of adaption processes of bacteria to antibiotic stress.


Assuntos
Adaptação Fisiológica/fisiologia , Antibacterianos/metabolismo , Bacillus subtilis/fisiologia , Estresse Fisiológico , Tetraciclina/metabolismo , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/metabolismo , Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Parede Celular/metabolismo , Proteômica , Transdução de Sinais , Tetraciclina/farmacologia
4.
Huan Jing Ke Xue ; 40(7): 3263-3269, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854727

RESUMO

The high content of tetracycline in municipal sludge may result in vermicomposting products carrying a high abundance of antibiotic resistance genes, thus lowering the utilization value of the vermicompost. Hence, this study aimed to reveal the underlying effects of tetracycline concentrations on the resistance genes involved in vermicomposting systems for sludge recycling. For this purpose, fresh sludge substrates with different concentrations of tetracycline (100, 500, and 1000 mg·kg-1) were vermicomposted for 60 days using Eisenia foetida. In parallel, sludge treatment without the addition of the tetracycline was used as a control. During the experiment, changes in bacterial communities, tetracycline resistance genes (tetC, tetG, tetM, tetW, and tetX), and class 1 integron (intI1) were detected using high-throughput sequencing and qualitative PCR, respectively. The results showed that the addition of tetracycline reduced the abundance of Proteobacteria but increased the abundance of Bacteroidetes in the sludge vermicompost. Furthermore, the concentrations of tetracycline had a significant negative correlation with Shannon and Pielou indexes of bacterial diversity. In addition, tetracycline increased intI1 genes and tetracycline resistance genes in the sludge by 4.25 times and 4.7-186.9 times, respectively. Moreover, there was a significantly positive correlation between the abundance of tetM genes and tetracycline concentration. This study suggests that higher concentration of tetracycline in sludge can modify the microbial community structure of vermicompost, enhancing the abundance of antibiotic resistance genes and their associated dissemination risks.


Assuntos
Antibacterianos/farmacologia , Compostagem , Resistência Microbiana a Medicamentos/genética , Microbiota , Esgotos/microbiologia , Tetraciclina/farmacologia , Animais , Genes Bacterianos , Oligoquetos , Resistência a Tetraciclina/genética
5.
Int J Food Microbiol ; 311: 108356, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31670141

RESUMO

Different samples of three products including Bikalga and Soumbala from Burkina Faso (West Africa) and Ntoba Mbodi from Congo-Brazzaville (Central Africa) were evaluated. The bacteria (400) were phenotyped and genotypically characterized by Rep-PCR, PFGE, 16S rRNA and rpoB gene sequencing and spa typing. Their PFGE profiles were compared with those of 12,000 isolates in the Center for Disease Control (CDC, USA) database. They were screened for the production of enterotoxins, susceptibility to 19 antimicrobials, presence of 12 staphylococcal toxin and 38 AMR genes and the ability to transfer erythromycin and tetracycline resistance genes to Enterococcus faecalis JH2-2. Fifteen coagulase negative (CoNS) and positive (CoPS) species characterized by 25 Rep-PCR/PFGE clusters were identified: Staphylococcus arlettae, S. aureus, S. cohnii, S. epidermidis, S. gallinarum, S. haemolyticus, S. hominis, S. pasteuri, S. condimenti, S. piscifermentans, S. saprophyticus, S. sciuri, S. simulans, S. warneri and Macrococcus caseolyticus. Five species were specific to Soumbala, four to Bikalga and four to Ntoba Mbodi. Two clusters of S. gallinarum and three of S. sciuri were particular to Burkina Faso. The S. aureus isolates exhibited a spa type t355 and their PFGE profiles did not match any in the CDC database. Bacteria from the same cluster displayed similar AMR and toxin phenotypes and genotypes, whereas clusters peculiar to a product or a location generated distinct profiles. The toxin genes screened were not detected and the bacteria did not produce the staphylococcal enterotoxins A, B, C and D. AMR genes including blazA, cat501, dfr(A), dfr(G), mecA, mecA1, msr(A) and tet(K) were identified in CoNS and CoPS. Conjugation experiments produced JH2-2 isolates that acquired resistance to erythromycin and tetracycline, but no gene transfer was revealed by PCR. The investigation of the heterogeneity of Staphylococcus species from alkaline fermented foods, their relationship with clinical and environmental isolates and their safety in relation to antimicrobial resistance (AMR) and toxin production is anticipated to contribute to determining the importance of staphylococci in alkaline fermented foods, especially in relation to the safety of the consumers.


Assuntos
Enterotoxinas/genética , Staphylococcus , Antibacterianos/farmacologia , Burkina Faso , Coagulase/genética , Congo , RNA Polimerases Dirigidas por DNA/genética , Farmacorresistência Bacteriana/genética , Eritromicina/farmacologia , Genótipo , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Tetraciclina/farmacologia
6.
Arq Gastroenterol ; 56(4): 361-366, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31721972

RESUMO

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 <0.05 were considered statistically significant. RESULTS: A total of 41% of 1435 patients were detected to be infected with H. pylori by bacteriological culture in 2005-2007 period, meanwhile 32.7% from 220 patients were also infected in 2015-2017 period. The clinical isolates of H. pylori are mostly susceptible to amoxicillin and tetracycline (both over 98% of strains), but less susceptible to levofloxacin in both periods analysed (over 79% of the strains). On the other hand, metronidazole continuous showing the highest score of resistant isolates (over 40% of resistant strains), although an 18% fewer resistant strains were observed in 2015-2017 period. Clarithromycin, the key antibiotic in eradication therapies, has an increased frequency of resistant strain isolated in the decade (22.5% in 2005-2007 and 29.2% in 2015-2017). Multidrug resistant strains (two, three and four antibiotics) were also detected in both periods with the highest scores for simultaneous resistance to clarithromycin-metronidazole (18%) and clarithromycin-metronidazole-levofloxacin (12.5%) resistant strains. According to gender, the isolates resistant to amoxicillin, clarithromycin and metronidazole were more frequent in female, with a specific increment in amoxicillin and clarithromycin resistance. CONCLUSION: The frequency of clarithromycin resistance (29.2%) detected in 2015-2017 suggests that conventional triple therapy is no longer effective in this region.


Assuntos
Antibacterianos/farmacologia , Helicobacter pylori/efeitos dos fármacos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Amoxicilina/farmacologia , Chile , Claritromicina/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana Múltipla , Feminino , Infecções por Helicobacter/microbiologia , Humanos , Levofloxacino/farmacologia , Masculino , Metronidazol/farmacologia , Pessoa de Meia-Idade , Vigilância da População , Tetraciclina/farmacologia , Adulto Jovem
7.
Emerg Microbes Infect ; 8(1): 1553-1562, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31662120

RESUMO

Molecular epidemiology of Clostridium difficile infection (CDI) has been extensively studied in North America and Europe; however, limited data on CDI are available in the Asia-Pacific region. A multicentre retrospective study was conducted in this region. C. difficile isolates were subjected to multilocus sequence typing (ST) and antimicrobial susceptibility testing. Totally, 394 isolates were collected from Hangzhou, Hong Kong, China; Busan, South Korea; Fukuoka, Japan; Singapore; Perth, Sydney, Australia; New York, the United States. C. difficile isolates included 337 toxin A-positive/B-positive/binary toxin-negative (A+B+CDT-), 48 A-B+CDT-, and nine A+B+CDT+. Distribution of dominant STs varied geographically with ST17 in Fukuoka (18.6%), Busan (56.0%), ST2 in Sydney (20.4%), Perth (25.8%). The antimicrobial resistance patterns were significantly different among the eight sites (χ2 = 325.64, p < 0.001). Five major clonal complexes correlated with unique antimicrobial resistances. Healthcare-associated (HA) CDI was mainly from older patients with more frequent antimicrobial use and higher A-B+ positive rates. Higher resistance to gatifloxacin, tetracycline, and erythromycin were observed in HA-CDI patients (χ2 = 4.76-7.89, p = 0.005-0.029). In conclusion, multiple C. difficile genotypes with varied antimicrobial resistance patterns have been circulating in the Asia-Pacific region. A-B+ isolates from older patients with prior antimicrobial use were correlated with HA-CDI.


Assuntos
Antibacterianos/farmacologia , Infecções por Clostridium/microbiologia , Clostridium difficile/efeitos dos fármacos , Farmacorresistência Bacteriana , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ásia , Criança , Pré-Escolar , Clostridium difficile/classificação , Clostridium difficile/genética , Clostridium difficile/isolamento & purificação , Infecção Hospitalar/microbiologia , Eritromicina/farmacologia , Feminino , Gatifloxacina/farmacologia , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Filogenia , Tetraciclina/farmacologia , Adulto Jovem
8.
Future Microbiol ; 14: 1099-1108, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31512516

RESUMO

Aim: To describe the molecular types of Treponema pallidum and the proportion of macrolide and tetracycline resistance mutations in Barcelona. Materials & methods: Molecular type was determined using the Enhanced-CDC Typing system and antibiotic resistance was determined by sequencing the 23S and 16S rRNA genes. Results: A total of 183 patients were enrolled and 213 specimens (99 ulcers, 114 bloods) were collected. Sixty-two (70.5%) of 88 ulcers and 0 (0%) of bloods T. pallidum-DNA containing samples were fully typed. Up to 21 different strain types were identified (14d/g in 27.4%; 14f/g in 14.5%). Macrolide resistance mutations were present in 95% and tetracycline in 0%. Conclusion: Several different strains co-exist in Barcelona with a high proportion of macrolide resistance and absence of tetracycline resistance.


Assuntos
Farmacorresistência Bacteriana , Macrolídeos/farmacologia , Tipagem Molecular , Sífilis/epidemiologia , Tetraciclina/farmacologia , Treponema pallidum/classificação , Treponema pallidum/efeitos dos fármacos , Antibacterianos/farmacologia , DNA Bacteriano/genética , DNA Ribossômico/genética , Humanos , Mutação , Prevalência , Estudos Prospectivos , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Análise de Sequência de DNA , Espanha/epidemiologia , Sífilis/microbiologia , Treponema pallidum/genética , Treponema pallidum/isolamento & purificação
9.
Curr Microbiol ; 76(12): 1407-1416, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31555856

RESUMO

The study provides phenotypic and molecular analyses of the antibiotic resistance in 20 Lactobacillus strains including 11 strains newly isolated from fermented plant material. According to the results of disc diffusion method, 90% of tested lactobacilli demonstrated sensitivity to clindamycin and 95% of strains were susceptible to tetracycline, erythromycin, and rifampicin. Ampicillin and chloramphenicol were found to inhibit all bacteria used in this study. The vast majority of tested strains revealed phenotypic resistance to vancomycin, ciprofloxacin, and aminoglycosides. Most of Lactobacillus strains showed high minimum inhibitory concentrations (MICs) of cefotaxime, ceftriaxone, and cefazolin and therefore were considered resistant to cephalosporins. All the strains exhibited multidrug resistance. The occurrence of resistance genes was associated with phenotypic resistance, with the exception of phenotypically susceptible strains that contained genes for tetracycline (tetK, tetL) and erythromycin (ermB, mefA) resistance. The vanX gene for vancomycin resistance was among the most frequently identified among the lactobacilli (75% of strains), but the occurrence of the parC gene for ciprofloxacin resistance was sporadic (20% of strains). Our results mainly evidence the intrinsic nature of the resistance to aminoglycosides in lactobacilli, though genes for enzymatic modification of streptomycin aadA and aadE were found in 20% of tested strains. The occurrence of extended spectrum beta-lactamases (ESBL) was unknown in Lactobacillus, but our results revealed the blaTEM gene in 80% of strains, whereas blaSHV and blaOXA-1 genes were less frequent (20% and 15% of strains, respectively).


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Lactobacillus/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Laticínios/microbiologia , Eritromicina/farmacologia , Lactobacillus/classificação , Lactobacillus/genética , Lactobacillus/metabolismo , Testes de Sensibilidade Microbiana , Tetraciclina/farmacologia , Vancomicina/farmacologia
10.
J Food Sci ; 84(10): 2925-2931, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31546283

RESUMO

This study provides phenotypic and molecular analyses of the antibiotic resistance of Ensifer adhaerens strain YX1 (CICC 11008s), a strain that was identified using a polyphasic taxonomy approach. The antibiotic resistance profile of E. adhaerens YX1 was assessed using the Clinical & Laboratory Standards Inst. (CLSI) method. The strain was susceptible to ciprofloxacin, levofloxacin, norfloxacin, ofloxacin, gentamicin, tobramycin, chloramphenicol, tetracycline, imipenem, and ceftazidime, and resistant to kanamycin, streptomycin, fosfomycin, and nitrofurantoin. The antibiotic resistance genes nsfA, nsfB, fosA, aph, and aadA1 were not detected in E. adhaerens YX1 via PCR using gene-specific primers. Subsequently, the genome sequence of E. adhaerens was screened for antibiotic genes. Although no antibiotic resistance genes were identified using the ResFinder database, five genes copies of one resistance gene, adeF, were detected using the Comprehensive Antibiotic Resistance Database (CARD). The results of this study will be useful for understanding the phenotypic and genotypic aspects of E. adhaerens antibiotic resistance. No safety issues were identified for E. adhaerens YX1 in terms of antibiotic resistance. Performing similar studies will be conducive to the safety assessment and control of the use of E. adhaerens in the food and feed industry. PRACTICAL APPLICATION: Few relevant reports are currently available regarding antibiotic resistance assessments or other safety evaluations for Ensifer adhaerens. Because of a lack of relevant information on the safety of this bacterium, including the genetic basis of antibiotic resistance in the production strain, it has not been recommended for use in the "qualified presumption of safety" (QPS) list and subsequent updated lists. The current study shows no safety issue of E. adhaerens YX1 in terms of its antibiotic resistance. These results are important as they provide an initial basis for an understanding of the antibiotic resistance/susceptibility of E. adhaerens YX1 (CICC 11008s), which produces vitamin B12 and is widely used in the food and feed industry.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Rhizobiaceae/efeitos dos fármacos , Vitamina B 12/metabolismo , Ração Animal/microbiologia , Cloranfenicol/farmacologia , Ciprofloxacino/farmacologia , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Rhizobiaceae/metabolismo , Tetraciclina/farmacologia
11.
Curr Microbiol ; 76(11): 1306-1312, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471686

RESUMO

Wolbachia are the most common symbionts in arthropods; antibiotic treatment for eliminating the symbionts from their host is necessary to investigate the functions. Tetracycline antibiotics are widely used to remove endosymbiont Wolbachia from insect hosts. However, very little has been known on the effects of tetracycline on population size of Wolbachia in small brown planthopper (SBPH), Laodelphax striatellus (Fallén), an important insect pest of rice in Asia. Here, we investigated the dynamics of Wolbachia population density in females and males of L. striatellus by real-time fluorescent quantitative PCR method. The Wolbachia density in females and males of L. striatellus all declined sharply after treatment with 2 mg/mL tetracycline for one generation, and continued to decrease to a level which could not be detected by both qPCR and diagnostic PCR after treated for another generation, then maintained at 0 in the following three generations with continuous antibiotic treatment. Wolbachia infection did not recover in L. striatellus after stopping tetracycline treatment for ten generations. This is the first report to precisely monitor the population dynamics of Wolbachia in L. striatellus during successive tetracycline treatment and after that. The results provide a useful method for evaluating the efficiency of artificial operation of endosymbionts.


Assuntos
Antibacterianos/farmacologia , Hemípteros/microbiologia , Tetraciclina/farmacologia , Wolbachia/efeitos dos fármacos , Animais , Biodiversidade , Feminino , Masculino , Wolbachia/crescimento & desenvolvimento
12.
BMC Res Notes ; 12(1): 621, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547851

RESUMO

OBJECTIVE: To determine bacterial contaminants and their antimicrobial susceptibility patterns from medical equipment and inanimate surfaces. RESULTS: Of 130 swabs, 115 (88.5%) swabs were culture positive, of which contaminated medical equipment and inanimate surfaces account 70 (83.3%) and 45 (97.8%), respectively. All the swabs collected from sphygmomanometer, bedside table, computer and computer standing tables were 100% contaminated with bacteria. From the culture-positive swabs, a total of 171 bacterial isolates were identified, out of which 117 (68.4%) and 54 (31.6%) isolates were gram-positive and gram-negative, respectively. Most isolates (82%) were resistant to ampicillin and 13%, 8.6%, and 14% was observed in ciprofloxacin, gentamicin, and tetracycline respectively. Multi-drug resistant was observed in Escherichia coli (72.7%) and Staphylococcus aureus (58.7%).


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Contaminação de Equipamentos/estatística & dados numéricos , Fômites/microbiologia , Ciprofloxacino/farmacologia , Estudos Transversais , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Etiópia , Gentamicinas/farmacologia , Hospitais Especializados , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Tetraciclina/farmacologia
13.
Lett Appl Microbiol ; 69(4): 286-293, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392736

RESUMO

The prevalence of Listeria monocytogenes in the retail fish markets of the Kerala, India was investigated by screening 227 samples comprising of marine finfish (n = 97) shellfish (n = 19), ready-to-cook fish products (n = 47), ready-to-eat fish products (n = 10), dried fish (n = 11) and retail ice (n = 43). The prevalence of L. monocytogenes and L. innocua was 2·7% and 17·2% respectively. Sample category wise, prevalence of L. monocytogenes was higher in marine finfish (1·8%) and retail ice (0·9%). All the L. monocytogenes isolates carried virulent genes namely inlA, inlC, inlJ, hlyA, iap, plcA, prfA genes and majority (82%) belonged to 1/2a, 3a serogroups. L. monocytogenes isolates were multidrug-resistant and showed resistance to ampicillin, penicillin, erythromycin, tetracycline and clindamycin. Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) delineated 58% genetic heterogeneity among the L. monocytogenes strains. The study reports that genetic similarities of the isolates were interlinked to their serogroup and sample origin. SIGNIFICANCE AND IMPACT OF THE STUDY: Prevalence of Listeria monocytogenes, in the retail fish markets of Kerala, India was low but their relatively higher presence in marine finfish and retail ice and virulent nature of the isolates signifies food safety concerns. Moreover, multidrug-resistant nature of these isolates may potentially lead to spread of antimicrobial resistance. This study identified retail ice as a vehicle for entry of L. monocytogenes in retail fish and hence, there is a need to ensure quality of retail ice used for maintaining the cold-chain.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Listeria monocytogenes/efeitos dos fármacos , Alimentos Marinhos/microbiologia , Frutos do Mar/microbiologia , Ampicilina/farmacologia , Animais , Clindamicina/farmacologia , Eritromicina/farmacologia , Pesqueiros , Peixes/microbiologia , Microbiologia de Alimentos , Inocuidade dos Alimentos , Heterogeneidade Genética , Gelo/análise , Índia , Listeria monocytogenes/genética , Listeria monocytogenes/isolamento & purificação , Penicilinas/farmacologia , Prevalência , Sorogrupo , Tetraciclina/farmacologia
14.
J Med Microbiol ; 68(10): 1526-1533, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31418669

RESUMO

Introduction. Among beta-haemolytic streptococci, Streptococcus pyogenes (GAS) is the prototype agent of bacterial pharyngitis and causes other human infections. Streptococcus dysgalactiae subsp. equisimilis (SDSE) causes GAS-like infections, while Streptococcus agalactiae (GBS) is a common neonate pathogen that is rarely associated with pharyngitis.Aim. To determine the prevalence and persistence of beta-haemolytic streptococci throat carriage and type the bacterial population.Methods. Throat swabs were collected from 121 children and 127 young adult volunteers and cultured. Colonized volunteers were screened quarterly, for up to 1 year, while beta-haemolytic streptococci could be detected. Isolates were identified and submitted to antimicrobial susceptibility testing and epidemiological typing.Results. Carriage was detected in 34 (13.7 %) volunteers. Seventeen children carried GAS (14 %), while 17 young adults carried SDSE (8, 6.3 %), GBS (4, 3.1 %), GAS (3, 2.4 %) and the Streptococcus anginosus group (2, 1.6 %). Persistent carriage was detected for up to 6 months in two children and for up to 1 year in three young adults. Three new emm subtypes were found, emm87.16 and emm90.9 (GAS) and stC36.11 (SDSE). While the GAS population among children was unexpectedly clonal, substantial genetic diversity was found among the isolates recovered from young adults. Resistance to erythromycin, clindamycin and tetracycline was detected in GAS, GBS and SDSE recovered from young adults.Conclusions. Prevalence was slightly greater among children, but persistent carriage was greater among young adults, with SDSE being the species most associated with persistence. Few sources seemed to disseminate GAS among children, since only two clonal types were found. The volunteers hosted pathogenic streptococci persistently, including macrolide-resistant strains.


Assuntos
Portador Sadio/microbiologia , Faringe/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/isolamento & purificação , Adolescente , Adulto , Antibacterianos/farmacologia , Brasil/epidemiologia , Portador Sadio/epidemiologia , Criança , Pré-Escolar , Farmacorresistência Bacteriana , Feminino , Humanos , Macrolídeos/farmacologia , Masculino , Faringite/epidemiologia , Faringite/microbiologia , Estudos Prospectivos , Infecções Estreptocócicas/epidemiologia , Streptococcus/classificação , Streptococcus/efeitos dos fármacos , Streptococcus/genética , Tetraciclina/farmacologia , Adulto Jovem
15.
J Med Microbiol ; 68(9): 1287-1291, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31364966

RESUMO

The molecular mechanism of Helicobacter pylori resistance to tetracycline involves mutations in the primary binding site of the ribosome. A resistance or reduced susceptibility to tetracycline could be the result of single, double or triple mutations in the 16S rRNA gene of H. pylori. We investigated if the genotype was correlated to tetracycline resistance as determined phenotypically in vitro for 96 H. pylori isolates in the gastroesophageal mucosa of Venezuelan individual hosts. E-test for antimicrobial susceptibility test and real-time PCR for the detection of 16S rRNA gene mutations were performed in 96 H. pylori isolates (48 obtained from antrum, and 48 from oesophagus) from eight dyspeptic patients. In the gastric mucosa, 38 isolates were identified sensitive and 10 resistant to tetracycline by E-test, whereas 44 sensitive and 4 resistant isolates were found in the oesophagus. Real-time PCR detection of the 16S rRNA gene exhibited mutants with a single base-pair substitution (AGA926GGA) in six antrum isolates and seven oesophagus isolates, whereas only three harboured a low level of tetracycline resistance in vitro. Our results indicate that real-time PCR detection of 16S rRNA is a reliable method to classify among tetracycline-resistant genotypes and useful in patients who have experienced a first-line treatment failure with triple therapy.


Assuntos
Infecções por Helicobacter/microbiologia , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/genética , RNA Ribossômico 16S/genética , Resistência a Tetraciclina/genética , Tetraciclina/farmacologia , Antibacterianos/farmacologia , Mucosa Esofágica/microbiologia , Mucosa Gástrica/microbiologia , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Mutação , Reação em Cadeia da Polimerase em Tempo Real
16.
Int J Food Microbiol ; 305: 108252, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31276953

RESUMO

Shigella spp. can be isolated from various food sources and is responsible for many outbreaks and sporadic cases of foodborne diseases worldwide. Although Shigella species are known as one of the major foodborne pathogens, a few studies have characterized the prevalence and molecular basis of antibiotic resistance of Shigella spp. isolated from food origins. This study investigated the prevalence of Shigella spp. in a wide range of food samples (1400 samples), and the phenotypic and genotypic basis of antimicrobial resistance of the isolates. In addition, the potential of two Shigella specific phages (vB_SflS-ISF001 and vB_SsoS-ISF002) to control the growth of the isolates in food was tested. Shigella sonnei and Shigella flexneri were detected in 11 (0.8%) and 8 (0.6%) samples, respectively. The highest prevalence of Shigella spp. was observed in vegetables. Multidrug resistance phenotypes were noticeably frequent and observed in 17 isolates (89.5%) out of 19 isolates. Moreover, 13 (68.4%), 9 (47.4%) and 17 (89.5%) isolates were positive for ß-lactamase-encoding, plasmid-mediated quinolone resistance and tetracycline resistance genes, respectively. Treatment with the phages reduced bacterial counts up to 3 and 4 log when used individually or in cocktail form, respectively. The findings of this study indicate the prevalence of Shigella spp. in food sources and also provide useful information for a better understanding of the molecular aspects of antimicrobial resistance in Shigella spp.. The results also suggest that the combination of vB_SflS-ISF001 and vB_SsoS-ISF002 phages can effectively reduce contamination of two important species of Shigella in food.


Assuntos
Bacteriófagos/fisiologia , Queijo/microbiologia , Farmacorresistência Bacteriana , Fast Foods/microbiologia , Carne/microbiologia , Leite/microbiologia , Shigella/virologia , Verduras/microbiologia , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bovinos , Contaminação de Alimentos/análise , Contaminação de Alimentos/estatística & dados numéricos , Humanos , Testes de Sensibilidade Microbiana , Prevalência , Shigella/efeitos dos fármacos , Shigella/genética , Shigella/isolamento & purificação , Tetraciclina/farmacologia , beta-Lactamases/genética , beta-Lactamases/metabolismo
17.
Environ Int ; 131: 104989, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31302481

RESUMO

The human gut microbiome (GM) in healthy people is chronically exposed to tetracycline (TET) via environmental exposure and dietary uptake. However, limited information is available on its effect on the GM metabolome and effect on the host, especially at the dietary exposure level. Here, we investigated how TET at both sub-pharmaceutical and dietary exposure levels affects the metabolome and the secretome-induced host immune response by studying several representative gut bacteria. Interestingly, the metabolome showed a highly species-specific pattern with a distinct dose-response relationship. B. fragilis was highly sensitive to TET and vitamin, nucleotide, and amino acid metabolism pathways were the most vulnerable metabolic pathways at dietary exposure level. For key metabolite short chain fatty acids, TET significantly induced the synthesis of butyrate in B. fragilis, rather than C. sporogenes and E. coli. Furthermore, TET induced the release of lipopolysaccharides (LPS) in E. coli and enhanced the immune response; however, there was no obvious effect on B. fragilis. Interestingly, the overall immune response modulation with TET exposure relied on the ratio between E. coli and B. fragilis, possibly due to the neutralization of active LPS from E. coli by the LPS from B. fragilis. Overall, our results showed that the effect of TET from environmental exposure on the host health would be highly dependent on the GM composition, especially for the gut bacterial metabolome and secretome induced immune response.


Assuntos
Antibacterianos/farmacologia , Bacteroides fragilis/metabolismo , Clostridium/metabolismo , Escherichia coli/metabolismo , Imunidade Inata/efeitos dos fármacos , Tetraciclina/farmacologia , Bacteroides fragilis/efeitos dos fármacos , Clostridium/efeitos dos fármacos , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Redes e Vias Metabólicas/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Células THP-1
18.
Biomed Res Int ; 2019: 3917841, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31346516

RESUMO

In this study, the prevalence, phenotypes, and clonal relationships of Escherichia coli (E. coli) strains isolated from minks were investigated. In July 2017, a total of 62 fresh faecal swab samples were randomly collected from one large-scale mink farm in Zhucheng, Shandong Province, China. In all the samples, 50 E. coli strains were isolated and then assigned to serotyping, antimicrobial susceptibility test, detection of antimicrobial resistance genes and the Class 1 integrons, and multilocus sequence typing (MLST). Four pathogenic serotypes were identified among all the isolates, while the most common serotype was enterohemorrhagic E. coli O104:H4 (6.0 %). Antimicrobial sensitivity testing revealed that most isolates were susceptible to cefoxitin (96.0 %) and amikacin (82.0 %), while most isolates were resistant to ampicillin (92.0 %) and tetracycline (90.0 %). An analysis of the nucleotide sequences revealed that 7 isolates (14.0%) carried 4 types of Class 1 integron cassette, including dfrA27+aadA2+qnrA (57.1%), dfrA17+aadA5 (14.3%), dfrA12+aadA2 (14.3%), and dfrA1+aadA1 (14.3%). PCR screening showed that 14 antibiotic resistance genes were presented in 50 isolates, while the most prevalent resistance gene was qnrS, which was detected in 60.0 % of isolates, followed by sul2 (40.0%) and oqxA (38.0%). MLST analysis showed that 32 sequence types (STs) were identified, while ST46 was the predominant genotype among all isolates. Clonal complex 3 (CC3) was dominant. Compared with 340 human E. coli STs reported in China, the ST10 clonal complex, known as the largest human clonal complex, was also found in the 50 mink E. coli isolates. Meanwhile, mink-derived strain ST206 formed a new clonal complex, CC206, which was different from human ST strains. Our results showed that farmed minks could be reservoirs of antimicrobial-resistant E. coli with Class 1 integron cassettes and resistance genes, which were likely to pose a threat to public health. Therefore, continuous inspections and monitoring of E. coli in minks are essential for detecting and controlling emerging E. coli with different serovars as well as antibiotic resistance.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/microbiologia , Escherichia coli/genética , Vison/microbiologia , Agricultura , Amicacina/farmacologia , Ampicilina/farmacologia , Animais , Cefoxitina/farmacologia , China , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Vison/genética , Tetraciclina/farmacologia
19.
Microb Pathog ; 135: 103635, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31352064

RESUMO

OBJECTIVES: Mycoplasma hominis (M.hominis) infections are sexually transmitted and usually associated with urogenital and respiratory diseases. The aim of our study was to (i) detect M. hominis in the vaginal and urine samples of sexually active women using three different detection methods and (ii) to determine the antimicrobial susceptibility and recurrence after the treatment. METHODS: Both vaginal and urine samples were collected from 110 sexually active women at the Obstetrics and Gynecology Clinic, Baskent University Ankara Hospital, Turkey, between March 2015 and February 2016. The presence of M. hominis in the vaginal and urine samples was detected by in vitro culture, two biochemical diagnostics kits (Mycoplasma IES (Autobio, China) and Mycoplasma IST-2 (BioMérieux, France) and PCR. The antibiotic susceptibility of each sample was tested using the kits. The women positive for M. hominis were treated either singly or along with their sexual partners by tetracycline. RESULTS: M. hominis was detected in 72 of 220 (32.7%) samples (both vaginal and urine). Of which 37 showed contrary results with two different kits and then were confirmed by PCR. In 13 samples the IES kit identified M. hominis missed by IST-2, and in 8 samples the MIST-2 kit identified M. hominis missed by IES, while both kits missed 6 samples that were agar culture positive for M. hominis." The highest susceptibility rate was observed against pristinamycin (100%), followed by 91%, 83%, and 75% for doxycycline, tetracycline, and josamycin, respectively. Twenty-five patients treated with tetracycline were followed after one month. The recurrence of M. hominis was not observed in any of the 18 cases where both sexual partners were treated but recurred in 5 of the 7 singly treated women. CONCLUSIONS: The rate of M. hominis detection was significantly higher in the vaginal samples compared to the urine samples. The probability of detecting M. hominis by IST-2 kit was 1.18 times less than IES kit (p < 0.001). When the relationship between the samples was examined, the difference between IES and IST-2 for detecting M. hominis was statistically significant (p < 0.01). Antibiotic susceptibility tests indicated that the tetracycline group of antibiotics was effective in eliminating M. hominis when given to both the sexual partners.


Assuntos
Técnicas de Cultura de Células/métodos , Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/microbiologia , Mycoplasma hominis/crescimento & desenvolvimento , Mycoplasma hominis/isolamento & purificação , Patologia Molecular/métodos , Antibacterianos/farmacologia , Doxiciclina/farmacologia , Feminino , Hospitais Universitários , Humanos , Josamicina/farmacologia , Testes de Sensibilidade Microbiana , Infecções por Mycoplasma/tratamento farmacológico , Mycoplasma hominis/genética , Obstetrícia , Tetraciclina/farmacologia , Turquia , Vagina/microbiologia
20.
Environ Pollut ; 253: 152-160, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31306822

RESUMO

Antibiotic contamination caused by the long-term use of organic manure (OM) in greenhouse agricultural soils poses potential detrimental effects to the soil environment. By applying OM containing chlortetracycline (CTC) and/or ciprofloxacin (CIP) ten times in soil under laboratory conditions, we investigated the dissipation and accumulation characteristics of CTC and CIP in the soil, the changes in the microbial pollution-induced community tolerance (PICT), and the diversity and abundance of antibiotic resistance genes (ARGs) in the soil microbiome. The dissipation of CTC was rapid while CIP was accumulated in repeatedly treated soils; further, CIP could inhibit the dissipation of CTC. Meanwhile, the PICT to CTC and/or CIP significantly increased up to 15.0-fold after ten successive treatments compared to that in the first treatment. As the treatment frequency increased, significant upward trends in the abundances of tetracycline resistance genes tetA(G), tetX2, tetX, tetG, tetA(33), tetA, tetW, and tetA(P), fluoroquinolone resistance gene qnrA6, and multiple resistance gene mexF were revealed by both metagenomic and qPCR analyses. The findings demonstrated that repeated treatments with CTC and/or CIP can alter the dissipation rate, promote an increase in PICT to CTC and/or CIP, and increase the ARGs abundance in steps.


Assuntos
Antibacterianos/toxicidade , Clortetraciclina/toxicidade , Ciprofloxacino/toxicidade , Resistência Microbiana a Medicamentos/genética , Microbiologia do Solo , Agricultura , Clortetraciclina/análise , Esterco/análise , Metagenômica , Microbiota/efeitos dos fármacos , Solo , Tetraciclina/farmacologia , Resistência a Tetraciclina
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