Enteroaggregative Escherichia coli: Frequent, yet underdiagnosed pathotype among E. coli O111 strains isolated from children with gastrointestinal disorders in the Czech Republic.

Enteroaggregative Escherichia coli (EAEC) strains including those of serogroup O111 are important causes of diarrhea in children. In the Czech Republic, no information is available on the etiological role of EAEC in pediatric diarrhea due to the lack of their targeted surveillance. To fill this gap, we determined the proportion of EAEC among E. coli O111 isolates from children with gastrointestinal disorders ≤ 2 years of age submitted to the National Reference Laboratory for E. coli and Shigella during 2013-2022. EAEC accounted for 177 of 384 (46.1 %) E. coli O111 isolates, being the second most frequent E. coli O111 pathotype. Most of them (75.7 %) were typical EAEC that carried aggR, usually with aaiC and aatA marker genes; the remaining 24.3 % were atypical EAEC that lacked aggR but carried aaiC and/or aatA. Whole genome sequencing of 11 typical and two atypical EAEC O111 strains demonstrated differences in serotypes, sequence types (ST), virulence gene profiles, and the core genomes between these two groups. Typical EAEC O111:H21/ST40 strains resembled by their virulence profiles including the presence of the aggregative adherence fimbriae V (AAF/V)-encoding cluster to such strains from other countries and clustered with them in the core genome multilocus sequence typing (cgMLST). Atypical EAEC O111:H12/ST10 strains lacked virulence genes of typical EAEC and differed from them in cgMLST. All tested EAEC O111 strains displayed stacked-brick aggregative adherence to human intestinal epithelial cells. The AAF/V-encoding cluster was located on a plasmid of 95,749 bp or 93,286 bp (pAAO111) which also carried aggR, aap, aar, sepA, and aat cluster. EAEC O111 strains were resistant to antibiotics, in particular to aminopenicillins and cephalosporins; 88.3 % produced AmpC ß-lactamase, and 4.1 % extended spectrum ß-lactamase. We conclude that EAEC are frequent among E. coli O111 strains isolated from children with gastrointestinal disorders in the Czech Republic. To reliably assess the etiological role of EAEC in pediatric diarrhea, a serotype-independent, PCR-based pathotype surveillance system needs to be implemented in the future.

Effectiveness of tixagevimab/cilgavimab in patients with hematological malignancies as a pre-exposure prophylaxis to prevent severe COVID-19: a Czech retrospective multicenter study.

Despite lower virulence, the omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) still poses a relevant threat for immunocompromised patients. A retrospective multicentric study was conducted to evaluate the efficacy of pre-exposure prophylaxis with tixagevimab/cilgavimab (Evusheld) with a 6-month follow-up for preventing severe COVID-19 in adult patients with hematology malignancy. Among the 606 patients in the cohort, 96 (16%) contracted COVID-19 with a median of 98.5 days after Evusheld administration. A total of 75% of patients had asymptomatic or mild severity of COVID-19, while just 25% of patients with SARS-CoV-2 positivity had to be hospitalized. Two patients (2%) died directly, and one patient (1%) in association with COVID-19. Eight patients (1.3%) of every cohort experienced adverse events related to Evusheld, mostly grade 1 and of reversible character. It was found that complete vaccination status or positive seroconversion was not associated with lower risk of COVID-19 infection. Previous treatment with an anti-CD20 monoclonal antibody was associated with higher rates of COVID-19, while previous treatment with anti-CD38 monoclonal antibody was not, as was the case for recipients of hematopoietic stem cell transplantation or CAR-T cell therapy. Presence of other comorbidities was not associated with more severe COVID-19. The results support the growing evidence for Evusheld's efficacy against severe COVID-19 in patients with hematology malignancies.

A cross-border outbreak of Salmonella Bareilly cases confirmed by whole genome sequencing, Czech Republic and Slovakia, 2017 to 2018.

In August 2017, an increased incidence of Salmonella Bareilly was detected in the Czech Republic. An investigation was conducted with Slovakia to confirm the outbreak and identify the source. Probable outbreak cases were defined as cases with laboratory-confirmed S. Bareilly reported in either of the national surveillance systems, and/or the Czech and Slovak National Reference Laboratory databases from July 2017. Confirmed cases had the pulsed-field gel electrophoresis (PFGE) outbreak pulsotype or up to 5 alleles difference from outbreak cluster members by core genome multilocus sequence typing (cgMLST). PFGE and whole genome sequencing were used for isolate comparison. The same trawling questionnaire was used in both countries. By the end of October 2018, 325 cases were identified. Among 88 human S. Bareilly isolates analysed by PFGE, 82 (93%) shared an identical pulsotype; cgMLST of 17 S. Bareilly human isolates showed 1-2 allele difference. The trawling questionnaire excluded consumption of unusual or imported foods. In September 2018, an isolate closely related to the outbreak isolates was identified in a powdered egg product. A spray dryer was recognised as the contamination source and the production plant was closed. Using molecular typing methods, we detected a diffuse cross-border outbreak caused by S. Bareilly.

Presence of herpesvirus DNA in cerebrospinal fluid of patients with tick-borne encephalitis and enteroviral meningoencephalitis.

Reactivation of HHVs in the CNS due to inflammation has not been well described yet. The primary aim of this study was to investigate the frequency of HHV DNA detection in the cerebrospinal fluid (CSF) of immunocompetent patients with meningoencephalitis of other than HHV origin. The secondary aim of this study was to evaluate the impact of herpesvirus co-infection on the clinical course and patient outcome. Ninety-six patients with clinically and laboratory proven tick-borne encephalitis (TBE) and 77 patients with a confirmed diagnosis of enteroviral meningitis (EVM), along with a control group of 107 patients without evidence of inflammation in the CSF were retrospectively tested by nested PCR for the presence of DNA of the neurotropic herpesviruses HSV1, HSV2, VZV, and HHV6 in the CSF. The clinical course, laboratory tests, antiviral treatment, and neurological complications in a 6-month follow-up were compared between the groups positive or negative for HHV DNA in the CSF. HHV DNA was found in the CSF of 12 (6.9%) patients (6.3% and 7.8% in the TBE and EVM groups, respectively) and in 1 (0.9%) control patient. None of the patients had recent blisters or rash. The clinical course was comparably mild in all patients. No permanent neurological sequelae were observed. Only the CSF total protein level was significantly higher in HHV DNA-positive than in HHV-negative patients.

[Recurrent genital herpes]. / Recidivující genitální herpes.

In recent years, the rate of genital infections caused by Herpes simplex virus types 1 and 2 (HSV-1, HSV-2) has increased. Following primary infection with HSV-2, recurrent genital herpes (GH) often develops or asymptomatic virus shedding occurs. HSV-1-induced GH recurrencies are significantly less frequent. The options for diagnosing HSV infections have improved markedly: they include determination of type-specific antibodies in the blood (anti-HSV-1 and anti-HSV-2), culture of HSV from lesions or detection of viral antigens by immunohistochemistry methods; it is also possible to detect viral DNA by polymerase chain reaction. At present, recurrent genital herpes is treated by the so-called episodic therapy or suppressor antiviral therapy, in the Czech Republic based on acyclovir or valacyclovir. Preventive measures are possible only to a limited extent, particular attention is paid to pregnant women and the risk of disseminated herpes infection in newborns. New preventive and therapeutic options continue to be developed: a preventive vaccine against HSV-2 has been successfully tested, but this is effective only in HSV-1 negative women; experimental therapeutic vaccination stimulating specific immunity has not yet been successful.