Klinicka mikrobiologie a infekcni lekarstvi最新文献

The authors present three case reports of bacteremia with very rare microorganisms being isolated in the patients. Each brief case report is accompanied by etiological considerations related to the diagnosis and clinical condition of the patient. Routine microbiology tests were performed by examining the biochemical properties using commercial kits. Two methods were used to determine the microorganism species in the State Institute of Public Health in Prague: MALDI-TOF MS and 16S rDNA sequencing. Antibiotic susceptibility was assessed by the disk diffusion test; minimum inhibitory concentrations were determined using broth microdilution and the gradient diffusion method (E tests). This is probably the first reported case of Stenotrophomonas acidaminiphila isolated from human clinical specimens.

Given their wide therapeutic index, beta-lactam antibiotics are commonly used to treat critically ill patients. It is in these patients that significant heterogeneity in pharmacokinetics was noted, compared to the population average, especially in the volume of distribution, drug clearance and biological half-life, with values increasing as much as two-fold or, in the case of biological half-life, as much as four-fold. Significant pharmacokinetic changes also occur in cases of morbid obesity or renal insufficiency and when complex surgical techniques such as extracorporeal circulation are used. Therapeutic monitoring of piperacillin/tazobactam is a way to personalize and optimize therapy for these groups of patients. Preclinical data show a correlation between the probability of therapeutic success and concentrations of the unbound fraction of an antibiotic exceeding the minimum inhibitory concentration (MIC) for 40-50 % of the dosing interval. This time appears to be the preferred pharmacodynamic target for beta-lactam antibiotics. In critically ill patients, however, an even higher target may be required, ideally 100 % fT > 4xMIC. A better pharmacodynamic profile can be obtained using prolonged or continuous infusion. The biggest obstacle to routine TDM in β-lactams is the speed of quality sample determination. Currently, the most widely used method of measuring plasma concentrations is liquid chromatography coupled with UV or MS detection.

This case report describes the first case of imported scrub typhus in a Czech traveler. The infection was diagnosed in a 38-year-old male traveler returning from a one-week business/tourist trip to Laos who presented with fever, chills, joint and muscle pain, localized inguinal lymphadenopathy, rash and a typical eschar. Although laboratory findings included elevation of CRP, hepatic aminotransferases and lactate dehydrogenase, complete blood count revealed only borderline leukocytosis with mild thrombocytopenia. The diagnosis of scrub typhus was made by serological detection of specific antibodies. The patient was treated with a 200 mg daily dose of oral doxycycline for 20 days. His clinical course was uncomplicated. The case underpins the need for a broader differential diagnosis in patients with travel-related health problems, especially those presenting with fever and rash, including less common or neglected tropical diseases.

Objectives: The first case of coronavirus infection in the Moravian-Silesian Region was diagnosed on March 12, 2020. The study aimed to describe the first wave and clinical manifestation of the coronavirus epidemic at the Department of Infectious Diseases in Ostrava.

Material and methods: The sample comprised a total of 195 patients requiring hospitalization at the Department of Infectious Diseases in Ostrava between March 1 and August 31, 2020. The virus was diagnosed using polymerase chain reaction from nasopharyngeal swabs in 192 patients and from the bronchoalveolar lavage in one patient. In the other two patients, serological tests were applied using virus neutralization assays and ELISA specific antibodies.

Results: The sample included 100 men and 95 women. The mean age was 69.5 years. The most common diagnosis was pneumonia, observed in 123 patients (63 %). Respiratory symptoms without pneumonia were seen in 37 patients (19 %); loss of smell and taste in 14 patients (7 %); cardiovascular complications in 9 patients (5 %); acute psychosis in 2 patients (1 %); and diarrhea and vomiting in 25 patients (13 %). The remaining 23 patients (12 %) did not present any symptoms. The mean length of hospital stay was 11 days. The most frequent comorbidity was cardiovascular disease (70 %). A total of 39 patients died (20 %); their mean age was 77 years. Mechanical ventilation was started in 16 patients, of whom 7 died (43 %). The treatment was mostly symptomatic. Hydroxychloroquine was administered to 21 patients (11 %), favipiravir to 26 patients (13 %) and remdesivir to 13 patients (6 %).

Conclusion: Respiratory complications predominated in the majority of patients with coronavirus infection. In most cases, the treatment was symptomatic. One-fifth of the patients, mostly elderly ones, died.

In a group of 211 patients with chronic hepatitis C treated with direct-acting antivirals, four experienced therapy failure. Two patients, one originally treated with dasabuvir/ombitasvir/paritaprevir/ritonavir and the other with glecaprevir/pibrentasvir, received a triple combination of sofosbuvir, velpatasvir and voxilaprevir for 12 weeks. Following the retreatment, both patients were permanently virus-free.

Dark-pigmented microscopic fungi are worldwide-spread soil saprophytes often found on plant remnants. In chromoblastomycosis, infectious particles of these fungi enter the human body at the site of injury and may cause chronic infection, mainly in tropical and subtropical endemic areas. Chromoblastomycosis is almost exclusively diagnosed in patients with fully functioning immunity, with typically muriform cells present in infected tissue distinguishing this condition from phaeohyphomycosis. Phaeohyphomycosis, a less specific disease caused by dark-pigmented fungi, usually makes tissue necrotize rather than proliferate, involves a broader range of pathogens of the kingdom Fungi and is mainly associated with immune disorders. Chromoblastomycosis is usually a threat to male adults, globally considered an occupational disease affecting farmers, gardeners, loggers, agricultural commodity traders and other workers exposed to contaminated soil or handling materials of plant origin. In the Czech Republic, immunocompetent patients may be at risk of chromoblastomycosis as imported infection. In the past, however, the infection was also rarely documented as autochthonous in the country.

Cases of chromoblastomycosis are frequent in certain parts of the world, especially in some developing countries. Clinical manifestations of chromoblastomycosis are typical. To a certain extent, pathogens causing chromoblastomycosis overlap with those causing phaeohyphomycosis. Although cases of phaeohyphomycosis are not very common, they may end fatally. Therefore early management of these life-threatening infections is rather important. Targeted antifungal therapy and surgery are effective in combating these infections. Recently, several triazole antifungals such as posaconazole and isavuconazole have been available to treat even the most severe cases. Prevention of the infection should be aimed at reducing the risk of subcutaneous trauma, particularly in persons in contact with potential sources of infection such as wood materials important from endemic areas.

Background: Early and causal administration of antibiotics in patients with a positive blood culture is an essential prerequisite for successful treatment of infection. However, isolation and subsequent identification of bacteria in a blood culture by classical (culture) methods may last several days. MALDI-TOF MS is a method allowing rapid identification of bacteria, not only cultures from culture media, but also directly in clinical specimens.

Methods: The study included samples of positive blood cultures taken from patients in the University Hospital Olomouc between 2016 and 2018 and examined at the Department of Microbiology of the Faculty of Medicine, Palacký University Olomouc. Positive blood culture samples were processed using an in-house method involving the removal of blood cells by low-speed centrifugation. Subsequently, a pellet obtained by high-speed centrifugation and sample washing was tested by MALDI-TOF MS.

Results: A total of 110 positive blood cultures were examined using the method of direct identification. At a species level, more Gram-negative bacteria (88 %) than Gram-positive bacteria (79 %) were correctly identified, with higher identification score values being obtained for the former. Identification score values of 2.0 or higher were found in 62 % of blood cultures containing Gram-negative bacteria and 17 % of blood cultures containing Gram-positive bacteria. Identification score values ranging from 1.7 to 2.0 were found in 21 % of Gram-negative blood cultures and 33 % of blood cultures containing Gram-positive bacteria.

Conclusion: Direct identification of microorganisms from positive blood cultures using MALDI-TOF MS enables more rapid diagnosis. By reducing the time required to obtain the result of pathogen identification, it may positively affect the antibiotic treatment of patients.

Chromoblastomycosis and phaeohyphomycosis are less common fungal infections caused by dark-pigmented fungi. Virulence factors play an important role in the pathogenesis of these diseases. One of these factors, muriform cells, are the most important element for differential diagnosis of chromoblastomycosis and phaeohyphomycosis using clinical samples and various staining techniques. Accurate identification of pathogens causing chromoblastomycosis and phaeohyphomycosis is very important for correct and early antifungal therapy. Therefore, species identification of the etiological agent should be confirmed by sequencing of DNA from the culture. Early diagnosis may be crucial, especially in case of invasive forms of these infections. The diagnosis may be guided by some immunohistochemistry methods and DNA detection using polymerase chain reaction directly from clinical samples seems to be useful for identification of pathogens causing these severe and life-threatening infections.

The article discusses dalbavancin, a relatively new lipoglycopeptide antibiotic brought to market. It briefly describes the spectrum and mechanism of its antibacterial effect and dosing regimens that can be used in the treatment of skin and soft tissue infections. The authors present a case of a patient with shoulder phlegmon caused by MRSA who was successfully treated with this antibiotic.