RESUMEN
Clostridioides (Clostridium) difficile infection (CDI) is the most common causative pathogen of health care-associated gastrointestinal infections; however, due to the overlap of clinical symptoms with those of other causes of acute gastroenteritis, the selection of the most appropriate laboratory test is difficult. From April to October 2018, 640 stool samples requested for CDI testing were examined using the mariPOC CDI and Gastro test (ArcDia), which allows the detection of C. difficile glutamate dehydrogenase (GDH) and toxin A/B, norovirus genogroups GI and GII.4, rotavirus, adenovirus, and Campylobacter spp. In parallel, the C. Diff Quik Chek Complete test (Alere) was used as a routine diagnostic assay, and C. difficile toxigenic culture was used as a reference method. The sensitivity of the mariPOC CDI and Gastro test was comparable to that of C. Diff Quik Chek Complete for the detection of GDH (96.40% [95% confidence interval {CI}, 91.81% to 98.82%] versus 95.68% [95% CI, 90.84 to 98.40%]; P = 1.00) and was higher for the detection of toxin A/B (66.67% [95% CI, 57.36 to 75.11%] versus 55.56% [95% CI, 46.08 to 64.74%]; P = 0.00). The specificity of the mariPOC CDI and Gastro test was lower than that of C. Diff Quik Chek Complete for GDH detection (95.21% [95% CI, 92.96% to 96.91%] versus 97.60% [95% CI, 95.85% to 98.76%]; P = 0.04) and comparable to that of C. Diff Quik Chek Complete for toxin A/B detection (99.24 [95% CI, 98.05% to 99.79%] versus 99.81% [95% CI, 98.94% to 100.0%]; P = 0.37). In 29 cases (4.53%), other causative agents of diarrhea were detected (Campylobacter spp. [n = 17], rotavirus [n = 7], and norovirus genogroup GII.4 [n = 5]).
Asunto(s)
Clostridioides difficile , Infecciones por Clostridium/diagnóstico , Infecciones por Clostridium/microbiología , Heces/microbiología , Inmunoensayo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Bacterianas/genética , Toxinas Bacterianas/genética , Niño , Preescolar , Clostridioides difficile/enzimología , Clostridioides difficile/genética , Clostridioides difficile/inmunología , Infecciones por Clostridium/inmunología , Pruebas Diagnósticas de Rutina , Manejo de la Enfermedad , Enterocolitis Seudomembranosa/diagnóstico , Enterocolitis Seudomembranosa/inmunología , Enterocolitis Seudomembranosa/microbiología , Enterotoxinas/genética , Femenino , Glutamato Deshidrogenasa , Humanos , Inmunoensayo/métodos , Inmunoensayo/normas , Lactante , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Clostridium difficile has been recovered from the faeces of several animal species as well as horses. Between April 2015 and October 2016, 213 samples of faeces from non-hospitalized (nâ¯=â¯138) and hospitalized horses (nâ¯=â¯75) were investigated and eighteen C. difficile isolates were cultured using an enrichment method. Sixteen C. difficile positive samples were identified from hospitalised horses (pâ¯<â¯0.01). Molecular typing revealed seven ribotypes and sequence types (RT033/ST11 nâ¯=â¯8, 44.4%; RT081/ST9 nâ¯=â¯4, 22.2%; RT009/ST3 nâ¯=â¯2, 11.1%; RT003/ST12 nâ¯=â¯1, 5.6%; RT010/ST15 nâ¯=â¯1, 5.6%; RT012/ST54 nâ¯=â¯1, 5.6%; RT039/ST26 nâ¯=â¯1, 5.6%). Seven identified STs clustered to two clades (1 and 5). All C. difficile isolates were susceptible to amoxicillin, metronidazole, moxifloxacin, and vancomycin. One isolate (RT039) exhibited a high level of resistance to erythromycin and clindamycin (256â¯mg/L) and carried the ermB, adenine methylase gene. Five isolates were resistant to clindamycin at lower minimal inhibitory concentrations (MICsâ¯=â¯8-16â¯mg/L) and were susceptible to erythromycin and also ermB negative. All isolates were resistant to enrofloxacin (MICs ranged between 4 and 32â¯mg/L). Eight isolates were resistant to tetracycline (MICs 12-32â¯mg/L). Of them, four isolates carried the tetM gene and four isolates the tetW gene. In addition, the tetracycline resistance determinants identified were: tetA (P) (nâ¯=â¯4); tetB (P); and tetL (nâ¯=â¯1 each). The presence of tetW or tetM, together with other tet-class mechanisms, lead to an increase in the MICs to tetracycline. C. difficile isolates derived from Czech horses are identical to the ribotypes identified in humans and carry acquired antimicrobial resistance genes whose dissemination from veterinary healthcare sector to humans should be monitored by the "One health" approach.
Asunto(s)
Antibacterianos/farmacología , Clostridioides difficile/clasificación , Clostridioides difficile/efectos de los fármacos , Análisis por Conglomerados , Enrofloxacina/farmacología , Genotipo , Caballos/microbiología , Animales , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , República Checa , Genes Bacterianos , Pruebas de Sensibilidad Microbiana , Ribotipificación , Análisis de Secuencia de ADNRESUMEN
Clostridium difficile is a major nosocomial pathogen in humans with an increasing incidence in the community. The "one-health" approach of research is needed to investigate possible reservoirs of C. difficile and route of its transmission. The objective of this study is to investigate the occurrence of C. difficile in pigs in the Czech Republic with characterisation of the isolates to determine their genetic relatedness to C. difficile isolates from European and Asian pigs. A total of 198 pig faeces samples from 23 farms were investigated and of those 57 samples (55 piglets, 2 sows) from 11 farms were confirmed as C. difficile positive. The majority of C. difficile isolates belonged to the sequence type 11 and clade 5. The predominant ribotypes were 078 (nâ¯=â¯23), 078-variant (nâ¯=â¯5), 033 (nâ¯=â¯10) followed by RTs 150 (nâ¯=â¯7), 011 (nâ¯=â¯5), 045 (nâ¯=â¯4), 126, 014, 002 (nâ¯=â¯1, each). All isolates were susceptible to metronidazole, vancomycin and tetracycline. Isolates of RTs 150 and 078-variant were moxifloxacin resistant (MIC≥32â¯mg/L) and carried the amino acid substitution Thr82Ile in the GyrA. A multi-locus variable number tandem-repeats analysis (MLVA) revealed a clonal relatedness of isolates within individual farms and in C. difficile RT078 isolates between two Czech farms. Czech C. difficile RT078 isolates clustered with German C. difficile RT078 isolates and Czech C. difficile 078-variant isolates clustered with C. difficile RT078 isolates from Japan and Taiwan. This study found an emergence of C. difficile RT078 in Czech piglets that was related genetically to C. difficile RT078 isolates from Germany, Japan and Taiwan.
Asunto(s)
Clostridioides difficile/clasificación , Clostridioides difficile/genética , Infecciones por Clostridium/transmisión , Infecciones por Clostridium/veterinaria , Sustitución de Aminoácidos/genética , Animales , Antibacterianos/farmacología , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/microbiología , República Checa , Girasa de ADN/genética , Alemania , Japón , Metronidazol/farmacología , Pruebas de Sensibilidad Microbiana , Moxifloxacino/farmacología , Tipificación de Secuencias Multilocus , Ribotipificación , Porcinos , Taiwán , Tetraciclina/farmacología , Vancomicina/farmacologíaRESUMEN
Bacteroides pyogenes can cause infections in humans. We describe a case of bloodstream infection caused by Bacteroides denticanum that probably originated from a dog bite. MALDI-TOF MS misidentified this new species as B. pyogenes. Subsequent analysis using the 16S rRNA sequencing approach identified the species as B. denticanum.
Asunto(s)
Bacteriemia/microbiología , Infecciones por Bacteroides/microbiología , Bacteroides/aislamiento & purificación , Anciano , Animales , Bacteriemia/diagnóstico , Técnicas de Tipificación Bacteriana , Bacteroides/química , Bacteroides/clasificación , Bacteroides/genética , Infecciones por Bacteroides/diagnóstico , Perros , Femenino , Humanos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Two decontamination solutions, commercially produced BASEâ¢128 and laboratory decontamination solution (LDS), with analogous content of antibiotic and antimycotic agents, were compared in their antimicrobial efficiency and stability (pH and osmolarity). Both solutions were compared immediately after thawing aliquots frozen for 1, 3 or 6 months. Agar well diffusion method was used to test their antimicrobial efficiency against five human pathogens: Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli and Enterococcus faecalis. The difference in the inhibition of growth between the two decontamination solutions was mostly not statistically significant, with few exceptions. The most pronounced difference between the LDS and BASEâ¢128 was observed in their decontamination efficacy against E. coli and E. faecalis, where the LDS showed to be more efficient than BASEâ¢128. The osmolarity value of LDS decreased with cold-storage, the osmolarity values of the BASEâ¢128 could not be measured as they were below the range of the osmometer. Slight changes were found in pH of the less stable LDS solution, whose pH increased from initial value 7.36 ± 0.07 to 7.72 ± 0.19 after 6 m-storage. We verified that BASEâ¢128 and LDS are similarly efficient in elimination of possible placental bacterial contaminants and may be used for decontamination of various tissues.
Asunto(s)
Antiinfecciosos/farmacología , Descontaminación , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Concentración de Iones de Hidrógeno , Pruebas de Sensibilidad Microbiana , Concentración Osmolar , SolucionesRESUMEN
This study aimed to characterize Clostridium difficile isolates cultured from stool samples of patients with C. difficile infection (CDI) and swabs from a medical environment in a gastroenterology center in Tehran, Iran. A total of 158 samples (105 stool samples from hospitalized patients and 53 swabs from medical devices and the environment) were collected from January 2011 to August 2011 and investigated for the presence of C. difficile by direct anaerobic culture on a selective media for C. difficile. C. difficile isolates were further characterized by capillary electrophoresis (CE) ribotyping and toxin gene multiplex PCR. Of 158 samples, C. difficile was cultured in 19 of 105 stool samples (18%) and in 4 of 53 swabs (7.5%). C. difficile PCR ribotype (RT) 126 was the most common RT in the study (21.7%). Further RTs were: 001, 003, 014, 017, 029, 039, 081, 103 and 150. RTs 126, 001, 150 were cultured from both the stool samples and swabs of medical devices and the hospital environment which suggest a possible route of transmission.
Asunto(s)
Clostridioides difficile/clasificación , Clostridioides difficile/aislamiento & purificación , Equipos y Suministros/microbiología , Heces/microbiología , Variación Genética , Ribotipificación , Toxinas Bacterianas/genética , Clostridioides difficile/genética , Clostridioides difficile/crecimiento & desarrollo , Femenino , Hospitales , Humanos , Irán , Masculino , Reacción en Cadena de la PolimerasaRESUMEN
In 2014, 18 hospitals in the Czech Republic participated in a survey of the incidence of Clostridium difficile infections (CDI) in the country. The mean CDI incidence was 6.1 (standard deviation (SD):7.2) cases per 10,000 patient bed-days and 37.8 cases (SD: 41.4) per 10,000 admissions. The mean CDI testing frequency was 39.5 tests (SD: 25.4) per 10,000 patient bed-days and 255.8 tests (SD: 164.0) per 10,000 admissions. A total of 774 C. difficile isolates were investigated, of which 225 (29%) belonged to PCR ribotype 176, and 184 isolates (24%) belonged to PCR ribotype 001. Multilocus variable-number tandem repeat analysis (MLVA) revealed 27 clonal complexes formed by 84% (190/225) of PCR ribotype 176 isolates, and 14 clonal complexes formed by 77% (141/184) of PCR ribotype 001 isolates. Clonal clusters of PCR ribotypes 176 and 001 were observed in 11 and 7 hospitals, respectively. Our data demonstrate the spread of two C. difficile PCR ribotypes within 18 hospitals in the Czech Republic, stressing the importance of standardising CDI testing protocols and implementing mandatory CDI surveillance in the country.
Asunto(s)
Clostridioides difficile/clasificación , Clostridioides difficile/genética , Infecciones por Clostridium/epidemiología , Diarrea/microbiología , Heces/microbiología , Ribotipificación/métodos , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/diagnóstico , República Checa/epidemiología , Diarrea/epidemiología , Electroforesis Capilar , Hospitales/estadística & datos numéricos , Humanos , Incidencia , Notificación Obligatoria , Repeticiones de Minisatélite , Reacción en Cadena de la PolimerasaRESUMEN
PURPOSE: The objective of this survey was to determine the incidence of Clostridium difficile infections (CDI) at the Department of Infectious Diseases, Bulovka Hospital, and to evaluate clinical and epidemiological data on CDI patients together with a detailed molecular characterisation of C. difficile isolates. The patient outcomes were correlated to causative C. difficile PCR-ribotype. METHODS: The twelve-month study (2013) comprised patients two years of age and older with CDI. CDI severity was estimated using ESCMID criteria and ATLAS scoring. C. difficile isolates were further characterized using ribotyping, Multiple-Locus Variable Tandem-Repeats analysis (MLVA) and investigation of antibiotic-resistance determinants (gyrA, gyrB, rpoB, ermB). RESULTS: A total of 619 diarrhoeal stools were investigated. Seventy-two stool samples were GDH and toxin A/B positive, and 39 samples were GDH positive only and subsequently toxigenic C. difficile was cultured. In total, 111 C. difficile isolates were characterized, of which 64 (57.7%) belonged to PCR-ribotype 176. MLVA analysis of PCR-ribotype 176 isolates revealed 11 clonal complexes. Seventy-two isolates (64.9%) showed amino acid substitution Thr82Ile in the GyrA, and sixty-two isolates (55.9%) showed amino acid substitutions Arg505Lys together with His502Asn, or Asp492Glu together with Arg505Lys in the RpoB. Twelve isolates (10.8%) were ermB positive. Severe CDI according to the ESCMID criteria was recorded in forty-two patients (37.8%), and sixteen patients (14.4%) had ATLAS score ≥ 6. Twenty-nine patients (26.1%) had recurrent CDI and twenty-four patients (21.6%) died during the study period. CONCLUSIONS: A higher rate of severe CDI, recurrences and mortality in association with PCR-ribotype 176 infections were observed. The high incidence of PCR-ribotype 176 in the study, and the presence of clonal relatedness between PCR-ribotype 176 isolates, indicate its higher capacity to spread in a hospital setting, which in turn highlights the need to implement strict epidemic measures when PCR-ribotype 176 occurs.
Asunto(s)
Proteínas Bacterianas/genética , Clostridioides difficile/clasificación , Infección Hospitalaria/diagnóstico , Diarrea/diagnóstico , Enterocolitis Seudomembranosa/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Niño , Preescolar , Clostridioides difficile/efectos de los fármacos , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/mortalidad , Infección Hospitalaria/patología , Diarrea/tratamiento farmacológico , Diarrea/mortalidad , Diarrea/patología , Farmacorresistencia Bacteriana/genética , Enterocolitis Seudomembranosa/tratamiento farmacológico , Enterocolitis Seudomembranosa/mortalidad , Enterocolitis Seudomembranosa/patología , Femenino , Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Mutación , Estudios Retrospectivos , Ribotipificación , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: Clostridium difficile infection (CDI) is a major cause of antibiotic-associated diarrhoea. Given an increasing CDI incidence and global spread of epidemic ribotypes, a 1-year study was performed to analyse the molecular characteristics of C. difficile isolates and associated clinical outcomes from patients diagnosed with CDI in the Internal Medicine department at University Hospital Motol, Prague from February 2013 to February 2014. RESULTS: A total of 85 unformed stool samples were analysed and CDI was laboratory confirmed in 30 patients (6.8 CDI cases per 10,000 patient bed days and 50.6 CDI cases per 10,000 admissions). The CDI recurrence rate within 3 months of treatment discontinuation was 13.3% (4/30). Mortality within 3 months after first CDI episode was 26.7% (8/30), with CDI the cause of death in two cases. 51.9% of C. difficile isolates belonged to PCR-ribotype 176. MLVA of ribotype 176 isolates revealed two clonal complexes formed by 10/14 isolates. ATLAS scores and Horn's index were higher in patients with ribotype 176 infections than with non-ribotype 176 infections. CONCLUSION: This study highlights the clinical relevance of C. difficile PCR-ribotype 176 and its capacity to spread within a healthcare facility.
Asunto(s)
Antibacterianos/efectos adversos , Clostridioides difficile/clasificación , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/patología , Diarrea/inducido químicamente , Diarrea/patología , Ribotipificación , Anciano , Anciano de 80 o más Años , Antibacterianos/administración & dosificación , Clostridioides difficile/genética , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/microbiología , Infecciones por Clostridium/mortalidad , República Checa/epidemiología , Diarrea/epidemiología , Diarrea/microbiología , Heces/microbiología , Femenino , Hospitales Universitarios , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Recurrencia , Análisis de SupervivenciaRESUMEN
Antibiotic profiling of twenty Czech Clostridium difficile PCR-ribotype 176 isolates revealed a high level of resistance to erythromycin, ciprofloxacin and moxifloxacin (n = 20) and to rifampicin (n = 13). Accumulation of resistance mechanisms to multiple antibiotics highlight that PCR-ribotype 176 belong to problematic epidemic strains.
Asunto(s)
Antibacterianos/farmacología , Clostridioides difficile/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple , Enterocolitis Seudomembranosa/microbiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Clostridioides difficile/clasificación , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , República Checa , Humanos , Datos de Secuencia Molecular , Mutación , RibotipificaciónRESUMEN
The first case of Clostridium difficile RT027 infection in the Czech Republic (CZ) was identified. The patient had been hospitalised in Germany prior to moving to CZ. Multiple-Locus Variable number tandem repeat Analysis revealed a genetic relatedness between the patient's isolate and RT027 isolate collected in the German hospital.
Asunto(s)
Clostridioides difficile/clasificación , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/microbiología , Reacción en Cadena de la Polimerasa , Ribotipificación , Viaje , Anciano de 80 o más Años , Clostridioides difficile/genética , Infecciones por Clostridium/diagnóstico , República Checa , Femenino , Alemania , Hospitalización , Humanos , Repeticiones de MinisatéliteRESUMEN
Clostridium difficile infection (CDI) is a disease of varying severity. Its manifestations range from mild diarrhea to life-threatening paralytic ileus, painful distension of the large bowel, and sepsis. Another possible manifestation of the disease is recurring colitis that can exhaust the patient. For establishing the diagnosis, the patient's stool should be examined with two or three different microbiological methods (testing for clostridial toxins A and B; testing for clostridial glutamate dehydrogenase, anaerobic culture with specific media, or PCR detection of genes for production of clostridial toxins). An alternative way of assessing the etiology is colonoscopic examination; the disease is confirmed if characteristic patchy pseudomembranes are present in the bowel mucosa. Optimal treatment depends on severity of the disease and on the risk of recurrence. Metronidazole, vancomycin and fidaxomicin are used as basic drugs. Fecal transplantation is effective in recurrent disease. In the hospital setting, patients suffering from CDI should be isolated for the entire duration of diarrhea. Surveillance rules also should be applied, together with early treatment of symptomatic patients and prevention of the spread of the infection. Higher incidence of CDI in a ward implies that the local antibiotic prescription habits should be revised.
Asunto(s)
Antibacterianos/uso terapéutico , Clostridioides difficile/aislamiento & purificación , Enterocolitis Seudomembranosa/diagnóstico , Infecciones por Clostridium/microbiología , República Checa/epidemiología , Diarrea/microbiología , Enterocolitis Seudomembranosa/epidemiología , Enterocolitis Seudomembranosa/metabolismo , Heces/microbiología , Política de Salud , Humanos , Guías de Práctica Clínica como AsuntoRESUMEN
Clostridium difficile infection (CDI) is a disease of varying severity. Its manifestations range from mild diarrhea to life-threatening paralytic ileus, painful distension of the large bowel and sepsis. Another possible manifestation of the disease is recurrent colitis that can exhaust the patient. For establishing the diagnosis, the patient's stool should be examined with two or three different microbiological methods. Immunochemical testing for the presence of clostridial toxins A and B shows good specificity but poor sensitivity. Therefore, it must be combined with other methods: stool testing for glutamate dehydrogenase (Clostridium antigen), anaerobic culture or PCR detection. An alternative way of assessing the etiology is colonoscopic examination; the disease is confirmed if typical pseudomembrane isles are present in the bowel mucosa. The basic drugs to treat CDI are still metronidazole (oral or parenteral) and/or vancomycin (oral or rectal). Fidaxomicin seems to be promising. Stool transplant via a nasojejunal tube is effective in recurrent disease. In the hospital setting, patients suffering from CDI should be isolated for the entire duration of diarrhea. Surveillance rules should also be applied, together with early treatment of symptomatic patients and prevention of the spread of the infection. Higher incidence of CDI in a ward implies that the local antibiotic prescription habits should be revised.
Asunto(s)
Clostridioides difficile , Enterocolitis Seudomembranosa/diagnóstico , Enterocolitis Seudomembranosa/terapia , Enterocolitis Seudomembranosa/microbiología , Humanos , Factores de RiesgoRESUMEN
BACKGROUND: Mucormycosis is an invasive fungal disease severely complicating treatment of patients with hematologic diseases. Effective therapy is represented by the combination of surgery and amphotericin B administration and early initiation of the therapy is necessary for favorable outcome. The first clinical symptoms are usually non-specific and this can lead to late therapy onset. The objective of this retrospective work was to determine the frequency, risk factors and outcome of invasive mucormycosis in pediatric hematology patients. MATERIAL AND METHODS: The study cohort comprised 399 patients diagnosed with hematologic diseases in the Department of Pediatric Hematology and Oncology (DPHO), University Hospital Motol, Prague between 2005 and 2010. Risk factors for the development of mucormycosis, clinical symptoms and radiology and laboratory results were retrospectively evaluated. So were the therapy used and outcomes. The findings were analyzed using Fisher's exact test. RESULTS: During the selected period, mucormycosis was detected in 8 patients diagnosed with hematologic disease. The incidence of mucormycosis was 1.75 %. These conditions accounted for 20.6 % of all mycoses. In five patients, it was found as isolated infection; three cases were associated with other mycoses (one with candidiasis, two with aspergillosis). The most frequent underlying disease was acute leukemia; the most common risk factor was severe prolonged neutropenia (median duration 21.5 days). Three of eight patients survived mucormycosis, a mortality rate of 62.5 %. The effective therapy was amphotericin B administration in three patients (p = 0.02); in two of them, it was combined with radical surgery. CONCLUSION: In the cohort, the proportion of mucormycosis cases was surprisingly high when compared with other fungal diseases. Continuous surveillance of mucormycosis in the DPHO is needed. There was no significant influence of the combination of radical surgery and amphotericin B administration as compared to administration of amphotericin B alone. Nevertheless, according to the published data, we consider this approach as an optimal strategy for the management of mucormycosis at the present time.
Asunto(s)
Neoplasias Hematológicas/inmunología , Huésped Inmunocomprometido , Mucormicosis/diagnóstico , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Mucormicosis/microbiologíaRESUMEN
We report a reproducible preparation and characterization of highly homogeneous thermoplastic starch/pol(ε-caprolactone) blends (TPS/PCL) with a minimal thermomechanical degradation and co-continuous morphology. These materials would be suitable for biomedical applications, specifically for the local release of antibiotics (ATB) from the TPS phase. The TPS/PCL blends were prepared in the whole concentration range. In agreement with theoretical predictions based on component viscosities, the co-continuous morphology was found for TPS/PCL blends with a composition of 70/30 wt.%. The minimal thermomechanical degradation of the blends was achieved by an optimization of the processing conditions and by keeping processing temperatures as low as possible, because higher temperatures might damage ATB in the final application. The blends' homogeneity was verified by scanning electron microscopy. The co-continuous morphology was confirmed by submicron-computed tomography. The mechanical performance of the blends was characterized in both microscale (by an instrumented microindentation hardness testing; MHI) and macroscale (by dynamic thermomechanical analysis; DMTA). The elastic moduli of TPS increased ca four times in the TPS/PCL (70/30) blend. The correlations between elastic moduli measured by MHI and DMTA were very strong, which implied that, in the future studies, it would be possible to use just micromechanical testing that does not require large specimens.
RESUMEN
Outer membrane vesicles carrying ß-lactamase (ßLOMVs) protect bacteria against ß-lactam antibiotics under experimental conditions, but their protective role during a patient's treatment leading to the therapy failure is unknown. We investigated the role of ßLOMVs in amoxicillin therapy failure in a patient with group A Streptococcus pyogenes (GAS) pharyngotonsillitis. The patient's throat culture was examined by standard microbiological procedures. Bacterial vesicles were analyzed for ß-lactamase by immunoblot and the nitrocefin assay, and in vivo secretion of ßLOMVs was detected by electron microscopy. These analyses demonstrated that the patient's throat culture grew, besides amoxicillin-susceptible GAS, an amoxicillin-resistant nontypeable Haemophilus influenzae (NTHi), which secreted ßLOMVs. Secretion and ß-lactamase activity of NTHi ßLOMVs were induced by amoxicillin concentrations reached in the tonsils during therapy. The presence of NTHi ßLOMVs significantly increased the minimal inhibitory concentration of amoxicillin for GAS and thereby protected GAS against bactericidal concentrations of amoxicillin. NTHi ßLOMVs were identified in the patient's pharyngotonsillar swabs and saliva, demonstrating their secretion in vivo at the site of infection. We conclude that the pathogen protection via ßLOMVs secreted by the flora colonizing the infection site represents a yet underestimated mechanism of ß-lactam therapy failure that warrants attention in clinical studies.
RESUMEN
Background: In order to estimate the prevalence of plasmid borne colistin resistance and to characterize in detail the mcr-positive isolates, we carried out a sentinel testing survey on the intestinal carriage of plasmid-mediated colistin-resistant Enterobacteriaceae in hospitalized patients. Methods: Between June 2018 and September 2019, 1922 faecal samples from hospitalised patients were analysed by selective culture in presence of colistin (3.5 mg/L), and in parallel by direct detection of the mcr-1 to mcr-8 genes by qPCR. The mcr-positive isolates were characterised by whole-genome sequencing. Results: The prevalence of the mcr-1 gene was 0.21% (n = 4/1922); the mcr-2 to 8 genes were not detected. The mcr-1 gene was found to be localised in the IncX4 (n = 3) and IncHI2 (n = 1) plasmid type. One Escherichia coli isolate was susceptible to colistin due to the inactivation of the mcr-1 gene through the insertion of the IS2 element; however, the colistin resistance was inducible by culture in low concentrations of colistin. One human mcr-1 positive E. coli isolate was related genetically to the mcr-1 E. coli isolate derived from turkey meat of Czech origin. Conclusions:mcr-mediated colistin resistance currently poses little threat to patients hospitalised in Czech healthcare settings. The presence of the mcr-1 gene in the human population has a possible link to domestically produced, retail meat.
RESUMEN
BACKGROUND: Travellers were recognized as a risk cohort that can be colonized by mcr-1-mediated colistin-resistant Enterobacteriaceae. We aimed to investigate the carriage of mcr-mediated colistin resistance in Enterobacteriaceae in Czech travellers or expatriates residing temporarily in the Czech Republic. METHODS: Between August 2018 and September 2019, the stool samples were cultured in enrichment broth. The enriched cultures were tested for the presence of the mcr-1-8 genes and inoculated onto selective agar with colistin. Colistin-resistant Enterobacteriaceae were tested for the presence of the mcr-1-8 genes; the mcr-positive isolates were characterised by whole genome sequencing. RESULTS: From the 177 stool samples, 15 colistin-resistant Enterobacteriaceae isolates were cultured (7.9%); two of the E. coli isolates carried the mcr-1 gene (1.1%). In the E. coli multilocus sequence type (ST) 156, the mcr-1 gene was located in an ISApl1-mcr-1-orf-ISApl1 (Tn6330) and incorporated into the chromosome; in the E. coli ST23 isolate, the mcr-1 gene was harboured by the plasmid IncX4. Both of the mcr-1 positive E. coli isolates were multidrug-resistant and one isolate was an extended-spectrum ß-lactamase producer (blaCTX-M-27). CONCLUSION: Patients with an international travel history should be monitored for the carriage of the mcr-1 gene in order to prevent its dissemination into healthcare settings.
Asunto(s)
Colistina , Proteínas de Escherichia coli , Antibacterianos/farmacología , Cromosomas , Colistina/farmacología , Estudios Transversales , República Checa , Farmacorresistencia Bacteriana/genética , Enterobacteriaceae/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Humanos , Pruebas de Sensibilidad Microbiana , Plásmidos/genéticaRESUMEN
The treatment of infections caused by Clostridium difficile requires a comprehensive approach. The administration of antibiotics of choice (vancomycin or metronidazole) is crucial. The choice of particular agents is based on the severity and course of the disease. Besides antibiotics, alternative approaches continue to be of interest, especially in forms inadequately responding to antibiotic therapy and in case of recurring infections.
Asunto(s)
Antibacterianos/uso terapéutico , Clostridioides difficile , Infecciones por Clostridium/tratamiento farmacológico , Metronidazol/uso terapéutico , Vancomicina/uso terapéutico , Infecciones por Clostridium/complicaciones , HumanosRESUMEN
In recent years, Clostridium difficile has been among the most important nosocomial pathogens. It causes intestinal infectious diseases detectable by numerous laboratory methods. Given the severity of the diseases, some tests have proved inadequately sensitive. The article summarizes the first experience with the latest kits for early and sensitive detection of toxic strains of Clostridium difficile.