Klinicka mikrobiologie a infekcni lekarstvi最新文献

Cryptic species within the section Fumigati, that is Aspergillus fumigatus-like species, are increasingly reported in the literature as causative agents of invasive aspergillosis (IA) in both humans and animals. Their detection and proper identification are important, but even more important is to determine the susceptibility profile (minimum inhibitory concentrations, MICs) of the isolate to antifungals using appropriate methods. Cryptic species often demonstrate elevated MICs to drugs recommended for IA therapy such as voriconazole or amphotericin B. Presented is a case of pulmonary aspergillosis in a 63-year-old male heart transplant recipient. Aspergillus lentulus with reduced susceptibility to voriconazole and amphotericin B was identified as the causative agent of the infection using culture and DNA sequencing. Susceptibility to antifungals was confirmed by the standard EUCAST-AFST methods. Based on MIC values obtained in vitro, therapy was switched from voriconazole to posaconazole with excellent clinical effects. To the best of our knowledge, this is the first reported case of A. lentulus infection treated with posaconazole and, moreover, a successful one.

There is a lack of information in the literature about the course and risk of vertical transmission of tick-borne encephalitis (TBE) during pregnancy. Presented is a case report of a female patient in the 37th week of pregnancy infected by foodborne transmission. She developed meningitis with no neurological damage. Three weeks after the first symptoms, she gave birth to a healthy child who, at the age of 30 months, had a negative result of anti-TBE antibodies in both IgM and IgG classes. In the child, no signs of neurological injury or impaired psychomotor development were observed throughout the follow-up period.

Objectives: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in intensive care patients. The aim of the study was to evaluate the effect of previous antibiotic therapy on the incidence of VAP, mortality and spectrum of bacterial pathogens.

Material and methods: The retrospective, observational study comprised patients over 18 years of age meeting the clinical criteria of VAP. Controls were patients requiring mechanical ventilation for more than 48 hours with no signs of VAP. Each group was divided into two arms according to previous antibiotic therapy. Tracheal aspirates and oropharyngeal swabs were taken from all patients. Cultured isolates were identified using standard microbiological techniques. Antimicrobial susceptibility testing was performed according to the European Committee on Antimicrobial Susceptibility Testing guidelines. In both groups, 28-day mortality, 90-day mortality and multidrug-resistant (MDR) bacterial pathogen frequency were evaluated.

Results: The study included 49 patients (32 patients with previous antibiotic therapy, 17 antimicrobial-naive patients). The proportion of individuals with previous antibiotic therapy was significantly lower in VAP patients (34%) than among controls group (66%; p = 0.02). The VAP criteria were met by 23 patients (11 with previous antibiotic therapy, 12 without the therapy). The Enterobacteriaceae including extended-spectrum beta-lactamase-producing strains and Pseudomonas aeruginosa were the most common pathogens isolated. MDR pathogens were statistically significantly more frequent in patients with previous antibiotic therapy (77% vs. 33%; p = 0.047). In patients with previous antibiotic therapy, 28-day mortality was lower (18%; n = 2) than in antimicrobial-naïve patients (33%, n = 4; p = 0.640). The difference was more pronounced in 90-day mortality, albeit with low statistical significance (18%, n = 2 vs. 58%, n = 7; p = 0.089).

Conclusions: Previous antibiotic therapy was associated with a lower incidence of VAP and a higher frequency of MDR bacterial pathogens. VAP antibiotic therapy modified according to knowledge of previous antibiotic therapy and cultured isolates was correlated with lower 28-day and 90-day mortality rates.

Objective: Clostridioides difficile (formerly Clostridium difficile) is one of the main pathogens causing nosocomial infections today. It colonizes the intestines of patients receiving antibiotic therapy, causing unpleasant or even life-threatening conditions (diarrhea, toxic megacolon). Rapid and correct detection of strain toxigenicity is essential for treatment and isolation of patients. Simplexa C. difficile Direct Kit is a real-time PCR kit detecting the tcdB gene of C. difficile. The kit does not require DNA isolation; stool eluates are directly used for the reaction. The study aimed to verify the analytical properties of the kit by its comparison with culture and in-house multiplex PCR methods.

Material and methods: A total of 164 stool samples were prospectively tested using two immunoenzymatic kits (C. diff Quik Chek Complete and LIAISON C. difficile GDH, Toxins AandB). In 39 samples, the results were discrepant or unclear (GDH+TOX-). These samples were tested using in-house multiplex PCR and the Simplexa kit.

Results: The Simplexa kit had 94.7% sensitivity, 100% specificity, 100% positive predictive value and 95.2% negative predictive value. These parameters were calculated from the numbers of true-/false-positive and true-/false-negative results. True results were determined based on the consensus of culture and in-house multiplex PCR results. Another outcome of the study was comparison of the Quik Chek and LIAISON kits.

Conclusion: The analytical properties of the Simplexa kit were tested on 39 samples. These samples were selected for their unclear (GDH+TOX-) or discrepant results yielded by immunoenzymatic methods. Compared with culture and subsequent in-house PCR detection of the tcdB gene, the Simplexa kit showed properties declared by the manufacturer. An important advantage of the kit was the absence inhibitions when stool eluates were directly used for PCR reactions.

The emergence of plasmid-mediated colistin resistance carried by mcr genes and polymyxin resistance in carbapenem-resistant bacteria poses a threat to antibiotic therapy of bacterial infections. The worldwide spread of colistin resistance carried by mcr genes, particularly in Enterobacteriaceae, points to the possibility of the spread of this type of resistance also in non-fermenting Gram-negative bacteria such as Pseudomonas aeruginosa or Acinetobacter baumannii. This study provides information on the first described occurrence of the mcr-4 gene in A. baumannii isolated from imported turkey liver obtained in the retail market of the Czech Republic.

Influenza is an acute viral disease that causes influenza A, B, C. Clinically, flu is typically characterized by fever and respiratory symptoms, sometimes with the need for mechanical ventilation, less frequently by gastrointestinal symptoms and muscle problems; severe are cases with central nervous system involvement. The most common complication of influenza is secondary bacterial infection, typically pneumonia, which is most frequently caused by pneumococci and staphylococci. Every year, thousands of patients die of influenza or its complications. In the Czech Republic, namely the Moravian-Silesian Region, influenza B virus dominated the 2017/2018 flu season. Presented is a case of a 51-year-old male with influenza B as an etiologic agent of rapidly progressing muscle weakness and laboratory tests showing rhabdomyolysis and significantly elevated muscle enzyme and aminotransferase, resulting in acute respiratory failure and death.

Background: Vertical hepatitis C virus (HCV) transmission and persistence of anti-HCV antibodies were retrospectively investigated since 1999 in a group of 244 children whose mothers had a history of hepatitis C.

Material and methods: Initial examinations performed in most children at 6 months of age included the determination of anti-HCV antibodies, HCV nucleic acid (HCV RNA), and anti-HIV antibodies, with all children being negative for HIV. Further examinations with investigation of anti-HCV and HCV RNA were performed at half-year intervals until the disappearance of anti-HCV antibodies. Vertical HCV transmission was defined by HCV RNA positivity in at least 2 venous blood samples or at least two positive anti-HCV results in a child over 3 years of age.

Results: Vertical HCV transmission was detected in 11 out of 244 children (4.5%). Only 2 children spontaneously cleared HCV; positive anti-HCV antibodies were last detected when they were 8 years old. Chronic hepatitis C developed in 9 children, four of whom were infected with genotype 1b, 3 children with genotype 3a, one with genotype 1a, and the last one with genotypes 1a and 4. Antiviral treatment including conventional or pegylated interferon, or ribavirin, was administered to 3 children, with sustained elimination of the virus in 2 children. Although the proportion of children with positive anti-HCV antibodies declined gradually, anti-HCV positivity was reported in 6 uninfected children at 18 months of age but in none of them at the age of 2 years.

Conclusions: Vertical transmission of HCV was found in 11 out of 244 children; chronic hepatitis C was detected in 9 children; uninfected children cleared anti-HCV antibodies by 2 years of age.

Mycobacterium marinum is a slowly growing non-tuberculous (environmental, atypical) mycobacterium with zoonotic potential. It occurs in the aquatic environment and causes diseases in fish and other aquatic animals known as mycobacterioses. In humans, it primarily causes skin infections, which are most commonly located in the upper limbs. The disease commonly appears in connection with the aquarium environment and is thus referred to as fish tank granuloma. As with all mycobacterial diseases, treatment is complicated and lengthy. For a definitive determination of the pathogen, biological materials should always be examined in a laboratory specializing in diagnosing mycobacteria. Critical for the right diagnosis is proper sample collection and assessment of the patient's history. To detect mycobacteria, culture and microscopy are generally used. Species are identified using modern biological methods such as mass spectrometry (MALDI), polymerase chain reaction, hybridization probes or sequencing.

Bacterial persistence in clinical microbiology is a phenomenon where the bacterial subpopulation of any bacterial strain, without having been exposed to an antibiotic, is already persistent to it. In clinical bacterial strains, persistence is not tested at all and the role of this phenomenon in the treatment of bacterial infections has not yet been evaluated. Therefore, the aim of the article is to highlight the significance of this probably global phenomenon in the treatment of bacterial infections with antibiotics. Also described are the mechanisms of its origin and some manner that could potentially reduce the frequency of these antibiotic-resistant bacterial cells in the bacterial population.

Introduction: HEV infection is perceived as the cause of acute hepatitis in endemic areas. In addition, it may also manifest as a possible trigger of AD or acute-on-chronic liver failure (ACLF).

Objectives: To determine the prevalence of HEV infection as a trigger of AD/ACLF in patients admitted for decompensated ACLD (dACLD).

Methods: A retrospective study; data analysis of consecutive patients with dACLD admitted to a liver unit. Study interval: August 2016 - October 2017.

Inclusion criteria: AD, defined as the interval between the first manifestations of decompensation and admission ≤ 4 weeks; an anti-HEV ELISA antibody assay in the IgG and IgM classes (HEV Ab ELISA, DRG Instruments GmbH, Germany).

Exclusion criteria: chronic decompensation of liver cirrhosis, insufficient data. Recorded variables: gender, age, etiology of ACLD, Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh score (CTPS), anti-HEV IgG and IgM, ACLF 0-3, length of stay (LOS) in the hospital, mortality: in-hospital mortality (IHM), 30-day, 6-month, 1-year and overall mortality.

Results: Over the 15-month study interval, a total of 212 patients (pts) were admitted for dACLD, including 115 with AD (54 %). The final analysis comprised 91 pts with a mean age of 53.3 years (y); 56 % were men.

Etiology: ALD 81 %, autoimmune diseases 7 %, HCV 5 %, non-alcoholic steatohepatitis 3 %, HBV 2 %, others 2 %. The mean MELD score and CTPS were 22.5 and 10.5 points (p), respectively. HEV infection as a possible trigger of AD was found in 9 % of pts (AD 75 %, ACLF 1-12.5 %, ACLF 3-12.5 %). Between HEV-positive and HEV-negative patients, there were no significant differences in age (p = 0.11), gender (p = 0.13), median MELD score (p = 0.42), median CTPS (p = 0.57), LOS (p = 0.56), overall survival (p = NS), IHM (p = NS), 30-day (p = NS), 6-month (p = NS), 1-year (p = NS) and overall mortality (p = NS).

Conclusion: The prevalence of HEV infection as a trigger of AD was 9 %. There were no significant differences in recorded variables, including mortality, between HEV-negative and HEV-positive patients.