Escherichia coli and Klebsiella pneumoniae cause a wide range of infections. Multidrug-resistance strains carrying extended-spectrum β-lactamases (ESBLs) has become a growing problem worldwide. The CTX-M type ESBLs has emerged distinctly, especially in Escherichia coli and Klebsiella pneumoniae. CTX-M type has been associated with many outbreaks of infections both in the hospitals and community. CTX-M-15 is now identified as the most predominantly distributed CTX-M enzyme. Clonal outbreaks of CTX-M-15 producing Enterobacteriaceae have been described in many countries including the United Kingdom, and Escherichia coli is the most commonly involved species. A total of 100 isolates were received in 2010 from London St George’s hospital, England, 50 Escherichia coli, 17 Klebsiella spp, 9 Enterobacter spp, 13 Proteus spp, 6 Lactose fermenting coliforms, 2 Pantoea spp, one Serratia marcescens, one Morganella morganii, and one Hafnia alvei. The antimicrobial susceptibility results showed that 5 Escherichia coli and one Klebsiella pneumoniae isolates were found to be resistance to cefotaxime, ceftazidime, ceftriaxone, cefotaxime, ciprofloxacin, and gentamicin, making them multi-drug resistant bacteria. None of the isolates showed resistance to imipenem, ertapenem, or morepenem, thus making carbapenems the drug of choice for the treatment of these infections due to multi-resistant isolates. The overall frequency of CTX-M-15 type ESBL-producers detected in this study was 6 (6%) most of them 5/6 (83%) were from Escherichia coli and one was (17%) Klebsiella pneumoniae isolates. The 6 CTX-M-positive isolates were typed by PFGE, only two strains of Escherichia coli showed more than 85% similarity, owing to clonal homology for both strains. The rest strains showed less than 85% similarity. S1 nuclease plasmid profiles were obtained for ESBL-producers isolates. A total of one to three plasmids per isolate, ranging from approximately 78.0 to 152.0 kb, were observed. The plasmids from most isolates were assigned to be IncFA and IncFB replicons. Analysis of phylogenetic groups showed group A and group B2. The method of phylogenetic classification of exteraintestinal pathogenic Escherichia coli depends on examine and combination of two preserved genes (chuaA and yjaA) and the DNA fragment TSP. Primer walking and PCR experiments were used for the genetic environment studies which showed 5 different genetic constructions for the described blaCTX-M-15 genes. Conjugation studies were used to detect the transferability of the plasmids harbouring the reported blaCTX-M-15 genes. Three isolates were found transferable by conjugation. In conclusion, this study reports the presence of hospital highly resistant blaCTX-M-15 in St George’s hospital. The spread of blaCTX-M-15 is probably due to horizontal gene transfer harbouring ISEcp1 and the conjugative properties of plasmids carrying blaCTX-M-15.

Antibiotic resistance is a serious global public health problem. ESBLs are enzymes that destroy expanded-spectrum beta-lactam antibiotics rendering these drugs ineffective. Infection with ESBL-producing K.pneumoniae are hard to treat and result in longer hospital stay and higher mortality rates. The Clinical Laboratory Standard Institute (CLSI) have standard methods for detection of ESBL producing strains of bacteria in infected patients to guide antibiotic therapy, reduce the risk of mortality and risk of transmission. The presence of K.pneumoniae and E.coli which produce ESBLs have been confirmed in natural environments such as soil and water but no standard methods exist to identify directly and quantify these bacteria to understand the risk of human exposure in these settings. The purpose of this research is to assess the ability of an agar dilution method, using a differential agar Bio-Rad Rapid E.coli 2 agar utilized in environmental water quality studies, to identify correctly ESBL-producing K.pneumoniae. The minimum inhibitory concentration (MIC) of ceftriaxone antibiotic for wild-type ESBL producing K.pneumoniae isolates were compared on Mueller-Hinton broth (MHB) and Bio-Rad Rapid E.coli 2 agar. Using the MIC values, the isolates were classified as susceptible, intermediate or resistant. The MIC of wild-type strains of K.pneumoniae were above 4μg/mL for both methods on all susceptibility tests performed. The results of this research suggest that Bio-Rad Agar dilution method performed well, correctly identifying these strains as resistant to ceftriaxone, an indication of ESBL production. The Bio-Rad agar dilution method can be considered as a viable standard method for direct identification of ESBL-producing K.pneumoniae in natural environments.

by Yuen Pui-yee, Joyce. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 213-221). / Acknowledgments --- p.i / Abstract --- p.ii / List of Tables --- p.ix / List of Figures --- p.xi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Problems of Pollution From Textile Industries --- p.1 / Chapter 1.2 --- Current Treatment Methods of Wastewater from Textile Industries --- p.5 / Chapter 1.3 --- Adverse Effects of Dyes on the Environment --- p.11 / Chapter 1.4 --- Classification of Dyes --- p.16 / Chapter 1.5 --- Azo Dyes --- p.17 / Chapter 1.6 --- Metabolisms of Azo Dyes in Microbial and Animal Systems --- p.21 / Chapter 1.7 --- "Toxicity, Mutagenicity and Carcinogenicity of Azo Dyes" --- p.31 / Chapter 1.8 --- Removal of Azo Dyes --- p.35 / Chapter 1.8.1 --- Biological Methods --- p.35 / Chapter 1.8.2 --- Physico-chemical Methods --- p.49 / Chapter 1.9 --- Purposes of Study --- p.50 / Chapter 2. --- Objectives --- p.53 / Chapter 3. --- Materials and Methods --- p.54 / Chapter 3.1 --- "Isolation, Selection and Characterization of Methyl Red-degrading and N,N-Dimethyl-p-phenylene diamine-degrading Microbial Isolates" --- p.54 / Chapter 3.1.1 --- "Isolation of Methyl Red-degrading Microbial Isolates from Dye- containing Wastewater, Activated Sludge and Soil" --- p.54 / Chapter 3.1.2 --- Selection of Methyl Red-degrading Microbial Isolates --- p.56 / Chapter 3.1.3 --- "Enrichment of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria from Dye-containing wastewater, Activated Sludge and Soil" --- p.59 / Chapter 3.1.4 --- "Isolation of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.60 / Chapter 3.1.5 --- Selection of N，N-Dimethyl-p-phenylene diamine-degrading Bacteria --- p.60 / Chapter 3.1.6 --- "Identification of the Selected Methyl Red-degrading and N,N- Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.61 / Chapter 3.1.7 --- Correlationship of Dry Weight and Absorbance of Cells of Selected Methyl Red-degrading Bacterial Isolates --- p.63 / Chapter 3.2 --- "Characterization of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.64 / Chapter 3.2.1 --- "Chemical Stability of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.64 / Chapter 3.2.2 --- Change of UV-Vis Spectra of Methyl Red and N，N-Dimethyl-p- phenylene diamine at Different pH and Matrixes --- p.64 / Chapter 3.2.3 --- "UV-Vis Spectra and Standard Curves of Methyl Red, N，N- Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.66 / Chapter 3.2.4 --- "HPLC separation of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.67 / Chapter 3.3 --- Methyl Red Degradation by Selected Methyl Red-degrading Microbial Isolates --- p.68 / Chapter 3.3.1 --- "Monitoring of Percentage of Methyl Red Cleaved, Degradation Value of N,N-Dimethyl-p-phenylene diamine and o- Aminobenzoic acid, and Growth of Selected Methyl Red- degrading Bacteria by Spectrophotometric Analysis " --- p.68 / Chapter 3.3.2 --- Study of Degrading Products of Methyl Red by Selected Methyl Red-degrading Isolates --- p.71 / Chapter 3.4 --- Degradation of Other Azo Dyes by Selected Methyl Red-degrading Isolates --- p.73 / Chapter 4. --- Results --- p.74 / Chapter 4.1 --- "Isolation, Selection and Characterization of Methyl Red-degrading and N,N-dimethyl-p-phenylene diamine-degrading Microbial Isolates " --- p.74 / Chapter 4.1.1 --- "Isolation of Methyl Red-degrading Microbial Isolates from Dye- containing Wastewater, Activated Sludge and Soil " --- p.74 / Chapter 4.1.2 --- Selection of Methyl Red-degrading Microbial Isolates --- p.79 / Chapter 4.1.3 --- "Enrichment of N,N-dimethyl-p-phenylene diamine-degrading Bacteria from Dye-containing Wastewater, Activated Sludge and Soil " --- p.85 / Chapter 4.1.4 --- "Isolation of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.85 / Chapter 4.1.5 --- "Selection of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.90 / Chapter 4.1.6 --- "Identification of the Selected Methyl Red-degrading and N,N- Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.90 / Chapter 4.1.7 --- Correlationship of Dry Weight and Absorbance of Cells of Selected Methyl Red-degrading Bacterial Isolates --- p.94 / Chapter 4.2 --- "Characterization of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.94 / Chapter 4.2.1 --- "Chemical Stability of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.94 / Chapter 4.2.2 --- "Change of UV-Vis Spectra of Methyl Red and N,N-Dimethyl-p- phenylene diamine at Different pH and Matrixes " --- p.108 / Chapter 4.2.3 --- "UV-Vis Spectra and Standard Curves of Methyl Red, N，N- Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.123 / Chapter 4.2.4 --- "HPLC Separation of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.129 / Chapter 4.3 --- Methyl Red Degradation by Selected Methyl Red-degrading Microbial Isolates --- p.138 / Chapter 4.3.1 --- "Monitoring of Percentage of Methyl Red Cleaved and Degradation Value of N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid and Growth of Selected Methyl Red- degrading Bacterial Isolates by Spectrophotometric Analysis " --- p.138 / Chapter 4.3.2 --- Study of Degradation Products of Methyl Red by Selected Methyl Red-degrading Isolates by HPLC --- p.175 / Chapter 4.4 --- Degradation of Other Azo Dyes by Selected Methyl Red-degrading Isolates --- p.175 / Chapter 5. --- Discussion --- p.181 / Chapter 5.1 --- "Isolation, Selection and Characterization of Methyl Red-degrading and N,N-dimethyl-p-phenylene diamine-degrading Microbial Isolates " --- p.181 / Chapter 5.1.1 --- "Isolation and Selection of Methyl Red-degrading Microbes from Dye-containing Wastewater, Activated Sludge and Soil " --- p.181 / Chapter 5.1.2 --- "Isolation and Selection of N,N-Dimethyl-p-phenylene diamine- degrading Microbial Isolates from Dye-containing Wastewater, Activated Sludge and Soil " --- p.183 / Chapter 5.1.3 --- Identification of the Selected Methyl Red-degrading and N，N- Dimethyl-p-phenylene diamine-degrading Bacteria --- p.185 / Chapter 5.1.4 --- Correlationship of Dry Weight and Absorbance of Cells of Selected Methyl Red-degrading Bacterial Isolates --- p.185 / Chapter 5.2 --- "Characterization of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.186 / Chapter 5.2.1 --- "Chemical Stability of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid in 0.05 M phosphate buffer and 0.2MHC1 " --- p.186 / Chapter 5.2.2 --- "Change of UV-Vis Spectra of Methyl Red and N,N-Dimethyl-p- phenylene diamine at Different pH and Matrixes " --- p.187 / Chapter 5.2.3 --- "Change of UV-Vis Spectra of N,N-Dimethyl-p-phenylene diamine in Different Matrixes at Different pH " --- p.187 / Chapter 5.2.4 --- "UV-Vis Spectra and Standard Curve of Methyl Red, N,N- dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.188 / Chapter 5.2.5 --- "HPLC Separation of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.189 / Chapter 5.3 --- Methyl Red Degradation by Selected Methyl Red-degrading Microbial Isolates --- p.190 / Chapter 5.3.1 --- Effect of Glucose --- p.194 / Chapter 5.3.2 --- Effect of Ethanol --- p.196 / Chapter 5.3.3 --- Effect of Ammonium Sulphate --- p.198 / Chapter 5.3.4 --- Effect of Yeast Extract --- p.199 / Chapter 5.3.5 --- Effect of Phosphate Buffer (pH 7) --- p.200 / Chapter 5.3.6 --- Effect of pH --- p.201 / Chapter 5.3.7 --- Effect of Temperature at Static and Shaking Conditions --- p.203 / Chapter 5.3.8 --- Study of Degradation Products of Methyl Red by Selected Methyl Red-degrading Isolates by HPLC Analysis --- p.206 / Chapter 5.4 --- Degradation of Other Azo Dyes by Selected Methyl Red-degrading Isolates --- p.207 / Chapter 6. --- Conclusion --- p.209 / Chapter 7. --- References --- p.213 / Chapter 8. --- Appendix 1: Composition of Media --- p.222 / Appendix 2: Composition of Buffers --- p.225 / Appendix 3 --- p.228

No description available.

Increasing carbapenem resistance among clinical isolates of E. coli and K. pneumoniae has become a serious public health problem over the last decade. Molecular epidemiology studies have shown that there is a global dissemination of epidemic clones of carbapenem-resistant E. coli and K. pneumoniae. Besides, successful epidemic plasmids were reported to disseminate carbapenemase genes in Enterobacteriaceae. The wide spread of carbapenem-resistant E. coli and K. pneumoniae limits treatment options of the infection, poses severe challenges to clinical professionals and threatens our health. Recently, carbapenem-resistant E. coli and K. pneumoniae are increasingly reported in Hong Kong. In 2012, our group has documented the emergence of carbapenem-resistant clinical isolates in Hong Kong. The findings of the previous study showed that 26.1% of the Enterobacteriaceae isolates were confirmed to produce carbapenemase. Notably, a novel IncX3 plasmid was found to be involved in the dissemination of blaNDM-1 gene. However, the previous findings fail to explicate the carbapenem resistance mechanisms of the remaining non-carbapenemase producing isolates. Further investigation is needed to elucidate the situation. Firstly, we investigated the carbapenem resistance mechanism of carbapenem-resistant E. coli and K. pneumoniae isolates recovered from the Hong Kong West Cluster hospitals from 2010 to 2012. PCRs were used to detect carbapenemase genes (blaNDM, blaKPC, blaIMP, blaVIM and blaOXA-48), blaCTX-M ESBL genes and blaAmpC genes. SDS-PAGE was used to detect porin loss. Among the 92 isolates in this study, only nine (9.8 %) isolates were detected with carbapenemase genes. The blaCTX-M and/or blaAmpC β-lactamase genes plus porin loss were detected in 47 non-carbapenemase-producing isolates (16 E. coli and 31 K. pneumoniae). The resistance determinant profiles of these 16 E. coli included: blaCTX-M + porin loss (n= 10), blaCIT + porin loss (n = 1), blaCTX-M + blaCIT/DHA + porin loss (n = 5). The resistance determinant profiles of the 31 K. pneumoniae included: blaCTX-M + porin loss (n= 4), blaDHA + porin loss (n = 7), blaCTX-M + blaCIT/DHA + porin loss (n = 20). The results showed that apart from acquired carbapenemases, the production of AmpC β-lactamase and/or ESBLs plus porin loss played a main role in the carbapenem resistance mechanism of the carbapenem-resistant E. coli and K. pneumoniae isolates. Secondly, we accessed the clonal relatedness of the isolates. Multi-locus sequence typing results showed that 55 (77.5%) K. pneumoniae isolates fall into the clonal complex 37. Our results suggest that the CC37 K. pneumoniae are associated with the acquisition of DHA-1 β-lactamase, CTXM-1-group β-lactamase and porin alterations which could confer a high-level of resistance to carbapenems resulting in their predominance in this study. Finally, we characterized the plasmids that carry carbapenemase gene by S1-PFGE, Southern blot, plasmid replicon typing and whole plasmid sequencing. A novel IncX3 plasmid was found to carry blaKPC gene. Together with the previously reported blaNDM-1 carrying IncX3 plasmids, it shows that IncX3 plasmids might be new epidemic plasmids involved in the dissemination of carbapenemase genes. These novel IncX3 plasmids are worrisome. Nationwide surveillance and more epidemiological study of IncX3 plasmids are needed. (Word / published_or_final_version / Microbiology / Master / Master of Philosophy

Staff shortages and lack of space at Prince Mshiyeni Hospital in Umlazi, south of Durban, was blamed for an outbreak of Klebsiella that has claimed the lives of five babies. Contaminated intravenous equipment and poor infection control measures were found to be the source of an outbreak of Klebsiella Pneumoniae, which killed twenty-one babies in another KwaZulu-Natal hospital. "Several flaws were identified" with infection control methods, according to the report that was released and compiled by medical microbiologist Professor Willem Sturm of the Nelson R Mandela School of Medicine in Durban. Initial investigations at the Mahatma Gandhi Memorial Hospital north of Durban, found Klebsiella Pneumoniae on the hands of 10% of staff. Interviews revealed that the nursery was usually overcrowded, under-equipped and under-staffed, which worked against adherence to infection control. Early in the investigation at this hospital, a link was found to the babies' intravenous treatment and after other possibilities were ruled out, medication information for seventeen of the babies showed that they had received regular intravenous injections. The spread was attributed to multiple-use of units of the medication to save costs, inadequate hand washing practices and inappropriate hand wash facilities. Recommendations included sealing off the nursery with strict hygiene controls and abandoning the practice of multiple uses of units of intravenous preparations. "Such preparations should be used only once. Multiple-use for one patient should also not be done" Furthermore, long sleeves on gowns, white coats and uniforms, or personal wear should be forbidden, and rings and watches should not be worn on hands and wrists as these interfere with hand washing. Such recommendations, though pertinent, do not disguise the seriousness of this situation in our hospitals. / A case study submitted in partial fulfillment of the requirements for the degree of Masters in Public Administration.

Die Mehrzahl der jährlich 400.000 bis 600.000 Krankenhausinfektionen in Deutschland wird von Erregern der sog. ESCAPE-Gruppe (Enterococcus faecium, Staphylococcus aureus, Clostridium difficile, Acinetobacter baumannii, Pseudomonas aeruginosa und verschiedene Enterobacteriaceae, u.a. Klebsiella pneumoniae) verursacht. Besondere Sorge bereitet dabei die Ausbreitung von K. pneumoniae-Stämmen mit enzymvermittelter Resistenz gegenüber Carbapenem-Antibiotika (K. pneumoniae-Carbapenemase, KPC) und die Zunahme von C. difficile-Infektionen (CDI) durch hypervirulente Epidemiestämme (z.B. Ribotyp 027). Die spezifischen Erfahrungen eines prolongierten Ausbruchsgeschehens durch einen KPC-bildenden K. pneumoniae-Stamm (KPC-KP) am Leipziger Universitätsklinikum machen deutlich, dass bei diesem Erregertyp ein hohes Transmissionspotential bei enormer Tenazität (Umweltresistenz) zu berücksichtigen ist, ein Versagen von Standardhygienemaßnahmen in Betracht zu ziehen ist, und Infektionsketten oftmals unklar bleiben. Die Anwendung von Antibiotika ist bei KPC-KP-Infektionen auf einzelne Substanzen (Colistin, Tigecyclin, Gentamicin) beschränkt und vor allem bei immunsupprimierten Patienten (z.B. Lebertransplantierte) mit einem relevanten Risiko des Therapieversagens behaftet. Die Therapie von CDI wird gerade bei Immunsupprimierten durch eine steigende Zahl an Rezidiven erschwert, die teilweise antibiotisch (Vancomycin, Fidaxomicin) nicht beherrschbar sind, so dass alternative Therapieverfahren wie die fäkale Bakterientherapie („Stuhltransplantation“) zur Anwendung kommen. CDI-Rezidive, aber auch eine dauerhafte intestinale Besiedelung mit multiresistenten Enterobakterien wie KPC-KP, scheinen neben wirtsspezifischen Faktoren der Immunantwort durch eine Dysregulation der physiologischen intestinalen Standortflora mit Störung der Kolonisationsresistenz bedingt zu sein. Der Versuch einer Eradikationsbehandlung von Patienten mit persistierender intestinaler Besiedelung durch KPC-KP mittels oraler Applikation der nicht resorbierbaren Antibiotika Colistin und Gentamicin ist mit einem relevanten Risiko der Entstehung von Sekundärresistenzen behaftet. Die Zulassung neuer, besser wirksamer Antibiotika ist für die nächsten Jahre nicht in Sicht, so dass der Infektionsprävention überragende Bedeutung zukommt. Die Erfahrungen der KPC-Ausbruchsbewältigung am Leipziger Universitätsklinikum zeigen, dass nahezu lückenlose Compliance bei der Händedesinfektion, rigoros praktizierte und kontrollierte Barriere- und Isolationsmaßnahmen, Optimierung des Gebrauchs von Breitspektrum-Antibiotika (sog. „Antibiotic Stewardship“) und systematisches mikrobiologisches Erregerscreening dabei unabdingbar sind. Nachhaltige Verbesserungen hinsichtlich der globalen Ausbreitung von multiresistenten Krankenhausbakterien werden sich nur durch grundlegende Umgestaltungen in Umwelt, Landwirtschaft, Tierzucht und Gesundheitswesen mit sparsamer und möglichst gezielter Anwendung von Antibiotika erzielen lassen. Um Risikopopulationen hospitalisierter Patienten vor potentiell lebensbedrohlichen Erregertransmissionen effektiv schützen zu können, sind erweiterte Surveillance und konsequent umgesetzte krankenhaushygienische Maßnahmen erforderlich.

Syftet med denna magisteruppsats är att gå vidare med resultat från en kandidatuppsats (Westling, 2013) gällande opastöriserade franska mögel- och kittostar genom att undersöka vilka Enterobacteriaceae-arter som ett urval av de analyserade ostarna innehöll. API 20E används som identifieringssystem. Tre Enterobacteriaceae-arter gav acceptabel till utmärkt identifiering av 40 analyserade isolat från de fyra ostarna, nämligen Hafnia alvei, Escherichia coli och Klebsiella pneumoniae. Inga skillnader mellan de identifierade arterna vad gäller inverkan på smak- och doftupplevelser hos opastöriserade franska mögel- och kittostar gick att urskilja med tillgänglig sensorisk data från kandidatuppsatsen (Westling, 2013). Utifrån denna magisteruppsats räcker det inte med att dofta på ostarna för att säkerställa hygienisk kvalitet, ytterligare undersökningar behövs för att kunna identifiera vilka Enterobacteriaceae-arter de innehåller. Däremot skulle en förstudie i form av en sensorisk bedömning av opastöriserade mögel- och kittostar kunna påvisa om ett högt antal Enterobacteriaceae föreligger, vilka vid konsumtion kan vara sjukdomsframkallande.

Syftet med denna magisteruppsats är att gå vidare med resultat från en kandidatuppsats (Westling, 2013) gällande opastöriserade franska mögel- och kittostar genom att undersöka vilka Enterobacteriaceae-arter som ett urval av de analyserade ostarna innehöll. API 20E används som identifieringssystem. Tre Enterobacteriaceae-arter gav acceptabel till utmärkt identifiering av 40 analyserade isolat från de fyra ostarna, nämligen Hafnia alvei, Escherichia coli och Klebsiella pneumoniae. Inga skillnader mellan de identifierade arterna vad gäller inverkan på smak- och doftupplevelser hos opastöriserade franska mögel- och kittostar gick att urskilja med tillgänglig sensorisk data från kandidatuppsatsen (Westling, 2013). Utifrån denna magisteruppsats räcker det inte med att dofta på ostarna för att säkerställa hygienisk kvalitet, ytterligare undersökningar behövs för att kunna identifiera vilka Enterobacteriaceae-arter de innehåller. Däremot skulle en förstudie i form av en sensorisk bedömning av opastöriserade mögel- och kittostar kunna påvisa om ett högt antal Enterobacteriaceae föreligger, vilka vid konsumtion kan vara sjukdomsframkallande.

Entre membros da Família Enterobacteriaceae a produção de β-lactamases de espectro estendido (ESBL – Extended-Spectrum β-lactamase) se constitui em um importante mecanismo de resistência a antibióticos β-lactâmicos. O objetivo deste estudo foi determinar a prevalência de ESBL em diferentes gêneros da Família Enterobacteriaceae em um hospital universitário no sul do Brasil. Além disso, avaliou-se o teste de triagem proposto pelo CLSI, o teste que utiliza discos combinados e técnica de PCR para detecção de ESBL na Família Enterobacteriaceae. De forma complementar, foi feita pesquisa de KPC em amostras com resistência (plena ou intermediária) ao ertapenem. Foram analisados 731 isolados da Família Enterobacteriaceae, obtidos a partir de amostras clínicas de pacientes hospitalizados. A prevalência de isolados produtores de ESBL na Família Enterobacteriaceae foi de 26,8% (196/731). Destacam-se Providencia spp. com uma prevalência de 91,7% (11/12), seguida de Klebsiella pneumoniae com 56,7% (59/104) e Enterobacter spp. com 40,7% (48/118). Entre os antibióticos utilizados no Teste Confirmatório Fenotípico, a cefepima foi o substrato que detectou o maior percentual dos isolados (90,6% - 183/202) como produtores de ESBL. Utilizando a técnica de PCR foi possível detectar blaTEM em 89,6% (208/232), blaSHV em 59% (137/232) e blaCTX-M em 37,9% (88/232) dos isolados. Comparando o perfil de suscetibilidade global das amostras ESBL com as demais amostras consideradas como não produtoras de ESBL, notou-se um grande decréscimo na sensibilidade de todos antimicrobianos testados (p < 0,05) nas ESBL positivas. Apenas os carbapenêmicos (Imipenem e Meropenem) apresentaram total eficácia in vitro. Outros antibióticos com maior percentual de sensibilidade para isolados produtores de ESBL foram Amicacina, Doxaciclina e Piperacilina/Tazobactam com 35,1%, 29,9% e 28,0% de sensibilidade, respectivamente. Entre os microrganismos com teste de triagem para ESBL positivo, 39 apresentaram resistência (plena ou intermediária) ao ertapenem, mas em nenhuma destas amostras foi detectado o gene blaKPC por técnica de PCR.