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Streptococcus suis is an emerging zoonotic bacterium causing septicemia and meningitis in humans. Due to rapid disease progression, high mortality rate, and many underdiagnosed cases by time-consuming routine identification methods, alternative diagnostic testing is essential. Among 29 broadly accepted S. suis serotypes, serotypes 2 and 14 are high prevalent; however, many PCR assays showed an inability to differentiate serotype 2 from 1/2, and 1 from 14. In this study, we developed and validated a new multiplex PCR assay that facilitates the identification of only the 29 true serotypes of S. suis and simultaneously differentiates serotypes 1, 1/2, 2, and 14 within a single reaction. Importantly, the multiplex PCR could detect S. suis directly from positive hemocultures and CSF. The results revealed high sensitivity, specificity, and 100% accuracy with almost perfect agreement (κ = 1.0) compared to culture and serotyping methods. Direct detection enables a decrease in overall diagnosis time, rapid and efficient treatment, reduced fatality rates, and proficient disease control. This multiplex PCR offers a rapid, easy, and cost-effective method that can be applied in a routine laboratory. Furthermore, it is promising for developing point-of-care testing (POCT) for S. suis detection in the future.

Shiga toxins comprise a family of structurally and functionally related protein toxins expressed by serotype 1 and multiple serotypes of . While the capacity of Shiga toxins to inhibit protein synthesis by catalytic inactivation of eukaryotic ribosomes has been well described, it is also apparent that Shiga toxins trigger apoptosis in many cell types. This review presents evidence that Shiga toxins induce apoptosis of epithelial, endothelial, leukocytic, lymphoid and neuronal cells. Apoptotic signaling pathways activated by the toxins are reviewed with an emphasis on signaling mechanisms that are shared among different cell types. Data suggesting that Shiga toxins induce apoptosis through the endoplasmic reticulum stress response and clinical evidence demonstrating apoptosis in humans infected with Shiga toxin-producing bacteria are briefly discussed. The potential for use of Shiga toxins to induce apoptosis in cancer cells is briefly reviewed.

Background Dengue fever is a mosquito born disease associated with self-limited to life threatening illness. First detected in Senegal in the nineteenth century, and despite its growing incidence this last decade, significant knowledge gaps exist in our knowledge of genetic diversity of circulating strains. This study highlights the circulating serotypes and genotypes between January 2017 and December 2018 and their spatial and temporal distribution throughout all regions of Senegal. Methods We used 56 dengue virus (DENV) strains for the analysis collected from 11 sampling areas: 39 from all regions of Senegal, and 17 isolates from Thiès, a particular area of the country. Two real time RT-qPCR systems were used to confirm dengue infection and corresponding serotypes. For molecular characterization, CprM gene was sequenced and submitted to phylogenetic analysis for serotypes and genotypes assignment. Results Three dengue virus serotypes (DENV-1–3) were detected by all used methods. DENV-3 was detected in 50% (28/56) of the isolates, followed by DENV-1 and DENV-2, each representing 25% (14/56) of the isolates. DENV-3 belongs to genotype III, DENV-1 to genotype V and DENV-2 to Cosmopolitan genotype. Serotype 3 was detected in 7 sampling locations and a co-circulation of different serotypes was observed in Thiès, Fatick and Richard-toll. Conclusions These results emphasize the need of continuous DENV surveillance in Senegal to detect DENV cases, to define circulating serotypes/genotypes and to prevent the spread and the occurrence of severe cases.

Out of 236 samples collected from clinically suspected farms and yards, the genome of Marek’s disease virus was detected in 84 (35.59 %) samples. Results showed the significant prevalence of the virus in intensive production/commercial farms (92.86 % of total positive samples) and in the flocks of extensively raised poultry/small-scale farms (7.14 % of total positive samples). Nucleotide sequence analysis of the ICP4 gene revealed that Serbian strains were classified into A and C groups of serotypes 1, showing high similarity (>98 %) with very virulent plus (vv+MDV) pathotypes of the Hungarian strains. A retrospective analysis from 2015 to 2022 showed that the Marek disease virus continually circulates in Serbia. This study aimed to detect and molecularly characterize Marek’s disease virus strain in Serbia.

To investigate an outbreak of African horse sickness (AHS) on a horse farm in northeastern Thailand, we used whole-genome sequencing to detect and characterize the virus. The viruses belonged to serotype 1 and contained unique amino acids (95V,166S, 660I in virus capsid protein 2), suggesting a single virus introduction to Thailand.

Background Dengue is an important public health problem, which caused by the dengue virus (DENV), a single-stranded RNA virus consisted of four serotypes. Central nervus system (CNS) impairment in dengue usually results from DENV-2 or DENV-3 infection, which lead to life-threatening outcomes. Furthermore, neurological complications due to DENV-1 was rare especially in adult patients. Case presentation A 44-year-old man without comorbidities had lethargy after hyperpyrexia and a positive DENV NS1 antigen was detected for confirming the diagnosis of dengue on day 8 of onset. Then logagnosia, decreased muscle strength, delirium and irritability were occurred even radiographic examination were normal. He was treated with low-dose hormone, sedatives and gamma goblin with a short duration of 6 days. The cerebrospinal fluid (CSF) tests were persistent normal. However, presence of DENV-1 RNA was confirmed both in CSF and serum. Furthermore, the complete sequence of the DENV isolated from the patient’s serum was performed (GenBank No.: MW261838). The cytokines as IL-6, IL-10 and sVCAM-1 were increased in critical phase of disease. Finally, the patient was discharged on day 24 of onset without any neurological sequelae. Conclusion Encephalopathy caused by a direct CNS invasion due to DENV-1 during viremia was described in an adult patient. Treatment with low-dose hormone and gamma goblin was helpful for admission.

Use of 10-valent pneumococcal conjugate vaccine in Kenya has led to substantial reductions in vaccine-type pneumococcal carriage and invasive pneumococcal disease. However, analysis of recent surveillance data indicates an outbreak of vaccine-type serotype 1 in 2023 in Kibera, Kenya. Continued monitoring of invasive pneumococcal disease in Kenya is warranted.

Streptococcus pneumoniae serotype 1 is one of the most prevalent serotypes commonly associated with invasive pneumococcal disease cases and outbreaks worldwide. Several sequence types of this serotype have been identified globally, including those exhibiting both high virulence potential and antimicrobial resistance profiles. This systematic review presents the global distribution of clones of pneumococcal serotype 1, describing their circulating patterns in various regions in the world. A database search was conducted in Google Scholar, PubMed, Scopus, ScienceDirect, and Web of Science using keywords related to Streptococcus pneumoniae serotype 1. The inclusion criteria entailed peer-reviewed studies published in English describing the utilization of at least one molecular genotyping tool to identify S. pneumoniae serotype 1 clones based on their sequence types. Data extracted were managed and analyzed using Microsoft Excel 365 (Version 2108). Forty-three studies were finally included in the systematic review. A total of 103 MLST serotype 1 sequence types were identified in 48 countries. These clones were widely reported to be associated with invasive pneumococcal diseases. Globally, ST217 and ST306 clonal complexes (CC217 and CC306) were the predominant lineages of serotype 1 sequence types, exhibiting distinct continental distribution patterns. CC217, characterized by ST217, ST303, ST612, ST618, and ST3081, was predominant in Africa and Asia. ST306 clonal complex, which is grouped into ST306, ST304, and ST227 were mostly found in Europe, Oceania, North America, and some countries in South America. ST615 was predominant in Chile, Peru, and Argentina. The hypervirulence nature of serotype 1, coupled with its complex genetic diversity, poses a significant public health threat. Our findings emphasize the need for enhanced surveillance and targeted interventions to mitigate the spread of these hypervirulent clones, ultimately informing evidence-based strategies for disease prevention and control.

African horse sickness (AHS) is a highly infectious and often fatal disease caused by 9 serotypes of the orbivirus African horse sickness virus (AHSV). In March 2020, an AHS outbreak was reported in Thailand in which AHSV serotype 1 was identified as the causative agent. Trivalent live attenuated vaccines serotype 1, 3, and 4 were used in a targeted vaccination campaign within a 50-km radius surrounding the infected cases, which promptly controlled the spread of the disease. However, AHS-like symptoms in vaccinated horses required laboratory diagnostic methods to differentiate infected horses from vaccinated horses, especially for postvaccination surveillance. We describe a real-time reverse transcription PCR-based assay for rapid characterization of the affecting field strain. The development and validation of this assay should imbue confidence in differentiating AHS-vaccinated horses from nonvaccinated horses. This method should be applied to determining the epidemiology of AHSV in future outbreaks.

Background An outbreak of pneumococcal meningitis among non-infant children and adults occurred in the Brong-Ahafo region of Ghana between December 2015 and April 2016 despite the recent nationwide implementation of a vaccination programme for infants with the 13-valent pneumococcal conjugate vaccine (PCV13). Methods Cerebrospinal fluid (CSF) specimens were collected from patients with suspected meningitis in the Brong-Ahafo region. CSF specimens were subjected to Gram staining, culture and rapid antigen testing. Quantitative PCR was performed to identify pneumococcus, meningococcus and Haemophilus influenzae . Latex agglutination and molecular serotyping were performed on samples. Antibiogram and whole genome sequencing were performed on pneumococcal isolates. Results Eight hundred eighty six patients were reported with suspected meningitis in the Brong-Ahafo region during the period of the outbreak. In the epicenter district, the prevalence was as high as 363 suspected cases per 100,000 people. Over 95 % of suspected cases occurred in non-infant children and adults, with a median age of 20 years. Bacterial meningitis was confirmed in just under a quarter of CSF specimens tested. Pneumococcus, meningococcus and Group B Streptococcus accounted for 77 %, 22 % and 1 % of confirmed cases respectively. The vast majority of serotyped pneumococci (80 %) belonged to serotype 1. Most of the pneumococcal isolates tested were susceptible to a broad range of antibiotics, with the exception of two pneumococcal serotype 1 strains that were resistant to both penicillin and trimethoprim-sulfamethoxazole. All sequenced pneumococcal serotype 1 strains belong to Sequence Type (ST) 303 in the hypervirulent ST217 clonal complex. Conclusion The occurrence of a pneumococcal serotype 1 meningitis outbreak three years after the introduction of PCV13 is alarming and calls for strengthening of meningitis surveillance and a re-evaluation of the current vaccination programme in high risk countries.