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Characterization of antibiotic resistance in Listeria spp. isolated from slaughterhouse environments, pork and human infections

Moreno, Luisa Zanolli; Paixão, Renata; Gobbi, Débora Dirani Sena de; Raimundo, Daniele Cristine; Ferreira, Thaís Sebastiana Porfida; Moreno, Andrea Micke; Hofer, Ernesto; Reis, Cristhiane M. F; Matte, Glavur Rogerio; Matte, Maria Helena
Fonte: JIDC; Tramaniglio Publicador: JIDC; Tramaniglio
Tipo: Artigo de Revista Científica
ENG
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66.26%
Introduction: Listeria species are susceptible to most antibiotics. However, over the last decade, increasing reports of multidrug-resistant Listeria spp. from various sources have prompted public health concerns. The objective of this study was to characterize the antibiotic susceptibility of Listeria spp. and the genetic mechanisms that confer resistance. Methodology: Forty-six Listeria spp. isolates were studied, and their minimal inhibitory concentrations of antibiotics were determined by microdilution using Sensititre standard susceptibility MIC plates. The isolates were screened for the presence of gyrA, parC, lde, lsa(A), lnu(A), and mprF by PCR, and the amplified genes were sequenced. Results: All isolates were susceptible to penicillin, ampicillin, tetracycline, erythromycin, and carbapenems. Resistance to clindamycin, daptomycin, and oxacillin was found among L. monocytogenes and L. innocua, and all species possessed at least intermediate resistance to fluoroquinolones. GyrA, parC, and mprF were detected in all isolates; however, mutations were found only in gyrA sequences. A high daptomycin MIC, as reported previously, was observed, suggesting an intrinsic resistance of Listeria spp. to daptomycin. Conclusions: These results are consistent with reports of emerging resistance in Listeria spp. and emphasize the need for further genotypic characterization of antibiotic resistance in this genus; FAPESP...

Análise do perfil de resistência a antibióticos e detecção dos genes de virulência e resistência em Aeromonas provenientes de amostras ambientais; Analysis of antibiotic resistance profile and detection of virulence and resistance genes in Aeromonas from environmental samples.

Moura, Elisabeth Mendes Martins de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/08/2010 PT
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66.27%
INTRODUÇÃO: As Aeromonas são bactérias distribuídas predominantemente em meio aquático. São consideradas patógeno emergente, podendo causar doenças em peixes como também no homem. Os problemas mais comuns são a gastrenterite no homem e morte em peixes. OBJETIVO: Este estudo foi desenvolvido para comparar a identificação fenotípica com a genotípica, e também para conhecer o perfil de resistência aos antibióticos em Aeromonas caviae, A. aquariorum, e A. sanarellii isoladas do ambiente aquático e a presença de genes de virulência e resistência. MATERIAL E MÉTODOS: O DNA das 24 cepas em estudo foi extraído por choque térmico e purificado utilizando CTAB. Foram realizadas as PCRs para a detecção dos genes de virulência e dos genes de resistência, após a realização do antibiograma. RESULTADOS: Foram identificadas 4 A. caviae das quais 3(75,0 por cento) apresentaram pelo menos um dos genes act, ast ou alt. Das 3 A. aquariorum, 1(33,3 por cento) apresentaram positividade para os genes act e ast. Entre os 5 isolados de A. sanarellii 1(50,0 por cento) possuíam os genes alt e ast. Seis isolados não foram posicionados taxonomicamente entre as espécies descritas de Aeromonas, e dentre essas um exemplar apresentou o gene alt. Em relação às enzimas MBL e AmpC foram obtidos respectivamente: 3(100 por cento) e 3(100 por cento) em A. aquariorum; 2(50...

Relationship between biofilm formation and antibiotic resistance in commensal isolates of Staphylococcus epidermidis

Oliveira, Fernando; Melo, Luís D. R.; Cerca, Nuno
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 ENG
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66.41%
Staphylococcus epidermidis is a common bacterial coloniser of the normal human microflora and usually have a benign relationship with the host. For several years, S. epidermidis was regarded as a harmless commensal microorganism. However, this bacterium is now recognised as an opportunistic pathogen, representing a leading cause of healthcare-associated infections. The major recognised determinants in the pathogenesis of S. epidermidis infections are its ability to form thick and multilayered biofilms along with high resistance to several classes of antibiotics. Biofilms are defined as structured communities of microorganisms embedded in a self-produced matrix of extracellular polymeric. It is well established that bacteria exhibiting a biofilm phenotype are more recalcitrant to antibiotic therapy. Hence, these two pathogenic features stated above appear to be intimately related. The present study aimed to evaluate the pathogenic potential of commensal S. epidermidis isolates through the assessment of their biofilm formation ability and antibiotic susceptibility profiles, as well as to analyse the relationship between biofilm formation and antibiotic resistance. To achieve that, thirty-one S. epidermidis isolates from Portuguese healthy volunteers (obtained from September 2012 to April 2013) were tested for biofilm formation ability...

Antibiotic resistance in coagulase negative staphylococci isolated from wastewater and drinking water

Faria, Cátia; Vaz-Moreira, Ivone; Serapicos, Eduarda; Manaia, Célia M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2009 ENG
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66.22%
This study reports the antibiotic resistance patterns of coagulase negative staphylococci (CNS) isolated from a drinking water treatment plant (WTP), a drinking water distribution network, responsible for supplying water to the consumers (WDN), and a wastewater treatment plant (WWTP), responsible for receiving and treating domestic residual effluents. Genotyping and the 16S rRNA gene sequence analysis demonstrated a higher diversity of species both in the WTP (6 species/19 isolates) and WWTP (12 species/47 isolates) than in the WDN (6 species/172 isolates). Staphylococcus pasteuri and Staphylococcus epidermidis prevailed in the WTP and WDN and Staphylococcus saprophyticus in the WWTP. Staphylococci with reduced susceptibility (resistance or intermediary phenotype) to beta-lactams, tetracycline, clindamycin and erythromycin were observed in all types of water and belonged to the three major species groups. The highest resistance rate was found against erythromycin, presumably due to the presence of the efflux pump encoded by the determinant msrA, detected in the majority of the resistant isolates. This study demonstrates that antibiotic resistant CNS may colonize different types of water, namely drinking water fulfilling all the quality standards.

Factors influencing antibiotic resistance burden in municipal wastewater treatment plants

Novo, Ana; Manaia, Célia M.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2010 ENG
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66.19%
Municipal wastewater treatment plants are recognized reservoirs of antibiotic-resistant bacteria. Three municipal wastewater treatment plants differing on the dimensions and bio-treatment processes were compared for the loads of amoxicillin-, tetracycline-, and ciprofloxacinresistant heterotrophic bacteria, enterobacteria, and enterococci in the raw inflow and in the treated effluents. The sewage received by each plant, in average, corresponded to 85,000 inhabitant equivalents (IE), including pretreated industrial effluents (≤30%) in plant activated sludge, 105,000 IE, including pretreated hospital effluents (≤15%) in plant trickling filter, and 2,000 IE, exclusively of domestic sewage, in plant submerged aerated filter. The presence of pretreated industrial effluents or of pretreated hospital sewage in the raw inflow did not imply significantly higher densities (per milliliter or per IE) of antibiotic-resistant bacteria in the raw wastewater. Longer hydraulic residence periods (24 h) corresponded to higher bacterial removal rates than shorter periods (12 and 9 h), although such efficiency did not imply significant average decreases in the antibiotic resistance prevalence of the treated effluent. The bacterial loads in the treated effluent could be ranked according to the treatment efficiency...

Antibiotic resistance of Vibrio parahaemolyticus isolated from pond-reared Litopenaeus vannamei marketed in Natal, Brazil

Melo,Ligia Maria Rodrigues de; Almeida,Dulce; Hofer,Ernesto; Reis,Cristhiane Moura Falavina dos; Theophilo,Grace Nazareth Diogo; Santos,André Felipe das Mercês; Vieira,Regine Helena Silva dos Fernandes
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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66.32%
Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei) collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil) tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50%) presented multiple antibiotic resistance to ampicillin (90%) and amikacin (60%), while two strains (20%) displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90%, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29), indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

Incidence and transferability of antibiotic resistance in the enteric bacteria isolated from hospital wastewater

Alam,Mohammad Zubair; Aqil,Farrukh; Ahmad,Iqbal; Ahmad,Shamim
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2013 EN
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66.29%
This study reports the occurrence of antibiotic resistance and production of β-lactamases including extended spectrum beta-lactamases (ESβL) in enteric bacteria isolated from hospital wastewater. Among sixty-nine isolates, tested for antibiotic sensitivity, 73.9% strains were resistant to ampicillin followed by nalidixic acid (72.5%), penicillin (63.8%), co-trimoxazole (55.1%), norfloxacin (53.6%), methicillin (52.7%), cefuroxime (39.1%), cefotaxime (23.2%) and cefixime (20.3%). Resistance to streptomycin, chloramphenicol, nitrofurantoin, tetracycline, and doxycycline was recorded in less than 13% of the strains. The minimum inhibitory concentration (MIC) showed a high level of resistance (800-1600 µg/mL) to one or more antibiotics. Sixty three (91%) isolates produced β-lactamases as determined by rapid iodometric test. Multiple antibiotic resistances were noted in both among ESβL and non-ESβL producers. The β-lactamases hydrolyzed multiple substrates including penicillin (78.8% isolates), ampicillin (62.3%), cefodroxil (52.2%), cefotoxime (21.7%) and cefuroxime (18.8%). Fifteen isolates producing ESβLs were found multidrug resistant. Four ESβL producing isolates could transfer their R-plasmid to the recipient strain E. coli K-12 with conjugation frequency ranging from 7.0 x 10-3 to 8.8 x 10-4. The findings indicated that ESβL producing enteric bacteria are common in the waste water. Such isolates may disseminate the multiple antibiotic resistance traits among bacterial community through genetic exchange mechanisms and thus requires immediate attention.

Occurrence of heavy metals and antibiotic resistance in bacteria from internal organs of american bullfrog (Rana catesbeiana) raised in Malaysia

Lee,SW; Najiah,M; Wendy,W; Nadirah,M; Faizah,SH
Fonte: Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP Publicador: Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
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66.22%
A total of 40 bacteria have been successfully isolated from internal organs of the American bullfrog (Rana catesbeiana) raised in Malaysia, namely, eight isolates of Aeromonas spp., 21 of Edwardsiella spp., six of Flavobacterium spp. and five of Vibrio spp. In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3%) cases of sensitivity and 61 (7.3%) cases of partial sensitivity. Meanwhile, 297 (35.4%) bacterial isolates were registered as resistant. The multiple antibiotic resistance (MAR) index of each bacterial species indicated that bacteria from raised bullfrogs have been exposed to tested antibiotics with results ranging from 0.27 to 0.39. Additionally, high percentages of heavy metal resistance among these isolates were observed, with values ranging from 85.0 to 100.0%. The current results provided us information on bacterial levels of locally farmed bullfrogs exposed to copper, cadmium, chromium as well as 21 types of antibiotics.

Virulence factors and antibiotic resistance of Helicobacter pylori isolated from raw milk and unpasteurized dairy products in Iran

Mousavi,Soolmaz; Dehkordi,Farhad Safarpoor; Rahimi,and Ebrahim
Fonte: Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP Publicador: Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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66.22%
Background Despite the high importance of Helicobacter pylori, the origin and transmission of this bacterium has not been clearly determined. According to controversial theories and results of previous studies, animal source foods – especially milk – play an important role in the transmission of H. pylori to humans. The aim of the present study was to determine the distribution of vacA, cagA, iceA and oipA virulence factors in H. pylori strains isolated from milk and dairy products and study their antimicrobial resistance properties. Methods A total of 520 raw milk and 400 traditional dairy product samples were cultured and tested. Those that were H. pylori-positive were analyzed for the presence of vacA, cagA, iceA and oipA virulence factors. Antimicrobial susceptibility testing was performed by the disk diffusion method. Results One hundred and three out of 520 milk samples (19.8%) and 77 out of 400 dairy products samples (19.2%) were contaminated with H. pylori. The most frequently contaminated samples were ovine milk (35%) and traditional cheese (30%). Total prevalence of vacA, cagA, iceA and oipA factors were 75%, 76.6%, 41.6% and 25%, respectively. H. pylori strains of milk and dairy products harbored high levels of resistance to ampicillin (84.4%)...

Isolated cell behavior drives the evolution of antibiotic resistance

Artemova, Tatiana; Gerardin, Ylaine; Dudley, Carmel; Vega, Nicole M; Gore, Jeff
Fonte: John Wiley & Sons, Ltd Publicador: John Wiley & Sons, Ltd
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
66.36%
Bacterial antibiotic resistance is typically quantified by the minimum inhibitory concentration (MIC), which is defined as the minimal concentration of antibiotic that inhibits bacterial growth starting from a standard cell density. However, when antibiotic resistance is mediated by degradation, the collective inactivation of antibiotic by the bacterial population can cause the measured MIC to depend strongly on the initial cell density. In cases where this inoculum effect is strong, the relationship between MIC and bacterial fitness in the antibiotic is not well defined. Here, we demonstrate that the resistance of a single, isolated cell—which we call the single-cell MIC (scMIC)—provides a superior metric for quantifying antibiotic resistance. Unlike the MIC, we find that the scMIC predicts the direction of selection and also specifies the antibiotic concentration at which selection begins to favor new mutants. Understanding the cooperative nature of bacterial growth in antibiotics is therefore essential in predicting the evolution of antibiotic resistance.

Temperate bacteriophages and the molecular epidemiology of antibiotic resistance in Salmonella enterica.

Tan, Sophia
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
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66.45%
Foodborne diseases caused by non-typhoidal Salmonella represent an important public health problem worldwide (Zhao et al., 2003). The transmission of Salmonella between animals and humans has been well established in epidemiological studies. In the case of complicated illness caused by Salmonella where antibiotics need to be administered, treatment can be compromised if the infecting organism is resistant to the prescribed antimicrobial agent. This study and earlier studies have shown that many Salmonella carry temperate bacteriophages as lysogens. Many of these bacteriophages are capable of mediating generalised transduction (Schicklmaier and Schmieger, 1995; Schicklmaier et al., 1998; Mmolawa et al., 2002). Schmieger and Schicklmaier (1999) demonstrated that bacteriophages ES18 and PDT17 are capable of transduction of antibiotic resistance genes from DT104. Phage-mediated transduction of antibiotic resistance genes has been largely neglected in the study of genetic transfer of antibiotic resistance in bacteria. This study investigates whether bacteriophages exist in antibiotic resistant Salmonella isolates. Such temperate phages in antibiotic resistant isolates could play a significant role in the transfer of resistance to other species of enteric bacteria...

Towards an ecological approach to antibiotics and antibiotic resistance genes

Fajardo, Alicia; Linares, Juan F.; Martínez, José L.
Fonte: European Society of Clinical Microbiology and Infectious Diseases Publicador: European Society of Clinical Microbiology and Infectious Diseases
Tipo: Artículo Formato: 6080 bytes; image/gif
ENG
Relevância na Pesquisa
66.22%
Antibiotics are likely the most important compounds used for human therapy. Conversely, antibiotic resistance is a relevant medical problem. However, besides their relevance for human health, antibiotics and their resistance genes are important elements that can influence the structure of microbial populations. In this article, we discuss antibiotics and antibiotic resistance genes in non-clinical enviromnents.; This work was supported by grants BIO2005-04278, LSHMCT- 2005-518152 and LSHM-CT-2005-018705. A. Fajardo is the recipient of a fellowship from the Spanish ‘Ministerio de Educacion y Ciencia’. All authors declare no conflicts of interests; Peer reviewed

Magic bullets and moving targets : antibiotic resistance and experimental chemotherapy, 1900-1940

Gradmann, Christoph
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2011 ENG
Relevância na Pesquisa
66.28%
It was in the 1940s that antibiotic resistance arose as an object of study for clinical medicine. Somewhat earlier it had become an important analytical tool for bacterial geneticists. However, the concept of antibiotic resistance as an induced and inheritable trait of microbial species was introduced a generation earlier in the years preceding the First World War. The paper reconstructs the concept that was put forward by the German immunologist Paul Ehrlich in 1907. He came across the phenomenon when trying to develop chemotherapies for trypa n osomiasis, the best known of which is African sleeping sickness. However, resistance was studied by him for other than therapy-related purposes. It provided a productive laboratory model for the study of cell functions. Induced resistance to chemicals facilitated the development of ideas on the relation of a parasite’s cellular metabolism and of drug action, i.e. by providing a negative proof for the existence of chemoreceptors on the surfaces of parasite cells. This approach does also serve to explain why British and German researchers continued to study the phenomenon of induced resistance in microbes for decades —despite it being absent from clinical medicine. After all, there existed very few chemotherapies of infectious diseases prior to the arrival of the sulfa drugs. Moreover...

Variations in antibiotic resistance profile in Enterobacteriaceae isolated from wild Australian mammals

Sherley, Miranda; Gordon, David; Collignon, Peter J
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
66.34%
We carried out a retrospective analysis of 946 strains of Enterobacteriaceae isolated from wild Australian mammals between 1993 and 1997. The prevalence of resistance to fixed concentrations of 32 antimicrobial agents was determined, and the respective roles that taxonomic family of the host, state of origin and bacterial species play in defining prevalence and range of resistance were investigated. Our results demonstrated a low but widespread prevalence of antimicrobial resistance in wild isolates. Only amikacin, ciprofloxacin, meropenem and gentamicin inhibited growth in all 946 samples. There was extensive variation in the combination of antibiotics to which isolates were resistant, and multiple antibiotic resistance was common. Geographical location and host group significantly influenced the antibiotic resistance profile of an isolate, whereas bacterial species influenced both the resistance profile of an isolate and the number of antibiotics it was resistant to. The role of these factors in determining observed antibiotic resistance profiles suggests that any study measuring resistance in wild isolates should include the broadest possible range of bacterial species, host species and sampling locations. As such, this study provides an important new baseline for future measurements of antibiotic resistance in the Australian environment.

Antibiotic resistance in Streptococcus pneumoniae isolated from children

Nasrin, Dilruba; Collignon, Peter J; Wilson, Elena Alexandrovna; Pilotto, Louis; Douglas, Robert M
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
66.4%
Objective: To determine the level of antibiotic resistance in pneumoniae (S. pneumoniae) isolated from nasal swabs of healthy children. Method: Cross- sectional community survey. Setting: Survey was undertaken in general practice settings in Canberra during March and April 1998. Subjects: Four hundred and sixty-one children under 3 years of age enrolled in a general practice trial of clinical practice guidelines for antibiotic use. Outcome measures: Resistance to penicillin, erythromycin, co-trimoxazole, tetracycline, chloramphenicol and cefotaxime among the isolates of S. pneumoniae. Results: A total of 461 nasal swabs were collected and S. pneumoniae was isolated from 171 (37.1%). Penicillin resistance was found in 12.3% of these isolates, with high level resistance in 0.6%. Resistance rates were higher for cotrimoxazole (44.4%) and erythromycin (18.1%) than for penicillin. Multidrug resistance was found in 19% of these isolates. There was a significant association between the attendance at a day care centre and carriage of pneumococcus (53% vs 32%, odds ratio (OR) 2.4, 95% confidence interval (CI)1.5-3.7, P < 0.001). Children who attended day care centres and had received antibiotics during the 4 months prior to swab collection were three times more likely to carry an antibiotic-resistant isolate than children who had neither attended a day care centre nor received antibiotics (68% vs 40%...

Magic bullets and moving targets: antibiotic resistance and experimental chemotherapy, 1900-1940

Gradmann,Christoph
Fonte: Dynamis Publicador: Dynamis
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/01/2011 ENG
Relevância na Pesquisa
66.28%
It was in the 1940s that antibiotic resistance arose as an object of study for clinical medicine. Somewhat earlier it had become an important analytical tool for bacterial geneticists. However, the concept of antibiotic resistance as an induced and inheritable trait of microbial species was introduced a generation earlier in the years preceding the First World War. The paper reconstructs the concept that was put forward by the German immunologist Paul Ehrlich in 1907. He came across the phenomenon when trying to develop chemotherapies for trypanosomiasis, the best known of which is African sleeping sickness. However, resistance was studied by him for other than therapy-related purposes. It provided a productive laboratory model for the study of cell functions. Induced resistance to chemicals facilitated the development of ideas on the relation of a parasite's cellular metabolism and of drug action, i.e. by providing a negative proof for the existence of chemoreceptors on the surfaces of parasite cells. This approach does also serve to explain why British and German researchers continued to study the phenomenon of induced resistance in microbes for decades -despite it being absent from clinical medicine. After all, there existed very few chemotherapies of infectious diseases prior to the arrival of the sulfa drugs. Moreover...

Antibiotic resistance of neustonic and planktonic fecal coliform bacteria isolated from two water basins differing in the level of pollution

Skórczewski,Piotr; Mudryk,Zbigniew Jan; Jankowska,Marta; Perliński,Piotr; Zdanowicz,Marta
Fonte: UAM, Unidad Iztapalapa, Publicador: UAM, Unidad Iztapalapa,
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
66.28%
Antibiotic resistance of fecal coliform bacteria isolated from the surface microlayer and the subsurface layer of a polluted pond and a non-polluted lake was studied. On the basis of the conducted studies it was stated that the isolated fecal coliform bacteria from both aquatic basins showed various resistance to tested antibiotics. Enteric bacteria were the most resistant to ampicillin, clindmycin, novobiocin, penicillin and the most sensitive to amikacin, gentamycin, neomycin and oxytetracycline. Fecal coliform bacteria inhabiting the pond showed similar resistance to the majority of tested antibiotics than coliform bacteria isolated from the lake. The multiple antibiotic resistance (MAR) index value for fecal coliform bacteria was higher in the pond than the lake. Only in a downtown pond fecal coliform bacteria isolated from the subsurface water were more resistant to tested antibiotics than those inhabiting the surface microlayer. The antibiotic resistance level of the bacteria depended on the chemical structure of antibiotics.

Antibiotic resistance profiles of Escherichia coli isolated from different water sources in the Mmabatho locality, north-west province, South Africa

Kinge,Constance N. Wose; Ateba,C. Njie; Kawadza,D. Tonderai
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2010 EN
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66.34%
The antibiotic resistance profiles of Escherichia coli (E. coli), isolated from different water sources in the Mmabatho locality were evaluated. Water samples were collected from the local wastewater- and water-treatment plants, the Modimola Dam and homes in the area, and then analysed for the presence of E. coli, using standard methods. Presumptive isolates obtained were confirmed by the analytical profile index test. Antibiotic susceptibility testing was performed by the disc diffusion method. Of the 230 E. coli isolates tested, marked antibiotic resistances (over 70%) were observed for erythromycin, tetracycline, ampicillin, chloramphenicol and norfloxacin. Multiple antibiotic resistance patterns were also compiled. Overall, the phenotype T-Ap-E was frequent for E. coli isolated from the local wastewater and water-treatment plants, Modimola Dam and tap water. Cluster analysis performed showed a unique antibiotic resistance pattern which suggested a link between isolates from all sampling points. The findings indicated that improper wastewater treatment may have a potential impact on the dissemination and survival of E. coli, as well as other pathogenic bacteria in water for human and animal consumption. This may result in water- and food-borne disease outbreaks with a negative effect on antibiotic therapy.

Horizontal transfer of heavy metal and antibiotic-resistance markers between indigenous bacteria, colonizing mercury contaminated tailing ponds in southern Venezuela, and human pathogens

Gómez Calderón,Wileidy Andrea; Ball Vargas,María Mercedes; Botello Suárez,Wilmar Alirio; Yarzábal Rodríguez,Luis Andrés
Fonte: Organo Oficial de la Sociedad Venezolana de Microbiología. Publicador: Organo Oficial de la Sociedad Venezolana de Microbiología.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
66.22%
Bacteria colonizing heavily polluted tailing ponds in Southern Venezuela exhibit multiple resistances against mercurial compounds and antibiotics. The corresponding genetic determinants, mainly acquired through horizontal gene transfer, might also be transferred to pathogenic bacteria, an issue which represents an important risk to public health. In this work we show that indigenous, mercury-resistant bacterial strains isolated from a model tailing pond, located in El Callao (Bolivar State, Venezuela) and exhibiting a high concentration of soluble Hg, were able to transfer in vitro both heavy metal- and antibiotic resistance markers to potential human- and animal- pathogens (i.e. Escherichia coli and Pseudomonas aeruginosa). The frequencies of transfer ranged between 1.2x10-6 and 5.5x10-7 transconjugants per recipient. Transconjugants were also detected in the field, in model biofilms previously grown in natural sponges (Luffa cylindrica) and submersed in the ponds, at frequencies ranging from 1x10-4 to 5x10-3 transconjugants per recipient. These results are of particular relevance from the public health viewpoint, especially in light of the potential risk of horizontal flow of antibiotic resistance genes between indigenous bacteria and potential human pathogens.

Antibiotic resistance in clinical isolates of Pseudomonas aeruginosa in Jamaica

Brown,Paul D.; Izundu,Anicetus
Fonte: Organización Panamericana de la Salud Publicador: Organización Panamericana de la Salud
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2004 EN
Relevância na Pesquisa
66.27%
OBJECTIVE: To assess antibiotic resistance in clinical isolates of Pseudomonas aeruginosa in Jamaica, and to obtain baseline information on the presence of this important pathogen. METHODS: A total of 51 isolates of Pseudomonas aeruginosa, obtained from 162 clinical specimens from major hospitals and laboratories in seven parishes in Jamaica, were analyzed between May and August 2002. Isolates were tested against 18 different antibiotics by a disk diffusion method. RESULTS: Organisms were cultured from wound swabs (56%), high vaginal swabs (10.5%) and ear swabs (42.5%). Overall, the highest percentage rates of resistance were found for cefaclor (100% of all isolates), nalidixic acid (82.4%), kanamycin (76.5%), and trimethoprim/sulfamethoxazole (56.9%). Resistance rates were 25.5% or lower for tobramycin, gentamicin and polymyxin B, cefotaxime, ciprofloxacin and norfloxacin, piperacillin, carbapenems and amikacin. Forty-one isolates showed intermediate sensitivity to most of the antipseudomonal antibiotics, and the remaining 10 isolates were resistant to eight or more antibiotics. The multiresistant isolates, most of which were hospital isolates, were all resistant to tetracycline, nalidixic acid and trimethoprim/sulfamethoxazole, and highly (80%-90%) resistant to kanamycin...