Infectious Medicine最新文献

Background

Scrub typhus, an acute febrile disease caused by Orientia tsutsugamushi, is transmitted to humans through infected chigger mites. We present a case of scrub typhus in a previously healthy man from Shandong Province diagnosed using next-generation sequencing (NGS) and PCR and review recent literature on NGS for scrub typhus diagnosis.

Methods

NGS was utilized for testing whole blood collected on admission. Confirmatory testing was done by detecting IgM and IgG antibodies to Orientia in acute and convalescent sera by ELISA. Orientia 47-kDa protein gene TaqMan and standard PCR of the 56-kDa protein gene and Sanger sequencing were performed on eschar scab DNA.

Results

The NGS diagnosis was confirmed by 47-kDa protein gene TaqMan and sequencing of a fragment of the O. tsutsugamushi 56-kDa protein gene from the eschar scab. Analysis of this sequence and the NGS data indicated O. tsutsugamushi strain Cheeloo2020 is a novel genotype. Mapping of the NGS data against the O. tsutsugamushi Gilliam strain genome sequence identified 304 reads with high similarity.

Conclusions

NGS is not only useful for multiplex diagnosis of scrub typhus, but also provides insight into the genetic diversity of O. tsutsugamushi. The common failure to submit sequences to databases makes it difficult to determine the minimal quantity and quality of NGS data being used for the positive identification of Orientia DNA in clinical specimens.

Background

Vibrio cholerae N-acetylglucosamine-binding protein (GbpA) is a four-domain, secretory colonization factor which is essential for chitin utilization in the environment, as well as in adherence to intestinal cells. GbpA is also involved in inducing intestinal inflammation by enhancing mucin and interleukin-8 secretion. The underlying cell signaling mechanism involved in the induction of the pro-inflammatory response and IL-8 secretion has yet to be deciphered in detail.

Methods

Herein, the process through which GbpA triggers the induction of IL-8 in intestinal cells was investigated by examining the role of GbpA in intestinal cell line HT 29.

Results

GbpA, specifically through the fourth domain, forms a binding connection with Toll-like receptor 2 (TLR2) and additionally, recruits TLR1 along with CD14 within a lipid raft micro-domain to initiate the signaling pathway. Notably, disruption of this micro-domain complex resulted in a reduction in IL-8 secretion. The lipid raft association served as the catalyst that invoked a downstream cellular inflammatory signaling pathway. This cascade involved the activation of various MAP kinases and NFκB and assembly of the AP-1 complex. This coordinated activation of signaling molecules eventually leads to enhanced IL-8 transcription via increased promoter activity. These findings suggested that GbpA is a crucial protein in V. cholerae, capable of inciting a pro-inflammatory response during infection by orchestrating the formation of the GbpA-TLR1/2-CD14 lipid raft complex. Activation of AP-1 and NFκB in the nucleus eventually enhanced IL-8 transcription through increased promoter activity.

Conclusion

Collectively, these findings indicated that GbpA plays a pivotal role within V. cholerae by triggering a pro-inflammatory response during infection. This response is instrumented by the formation of the GbpA-TLR1/2-CD14 lipid raft complex.

Background

Fujian Province has one of the highest reported incidences of hepatitis B virus infection in China. This study aimed to provide a theoretical framework for preventing and controlling hepatitis B in Fujian Province, and to assess the trends and the spatial-temporal distribution patterns of hepatitis B in this region.

Methods

Data on hepatitis B cases were extracted from the National Notifiable Infectious Disease Surveillance System. Spatial autocorrelation analysis, trend surface analysis, and spatial-temporal scanning statistics were used to identify the spatial and aggregation patterns at the county level. The Joinpoint was used to assess the reported incidence trends.

Results

The average reported incidence of hepatitis B in Fujian from 2012 to 2021 was 14.46/10,000 population, with 583,262 notified cases. The age-adjusted reported incidence of hepatitis B decreased from 17.44/10,000 population in 2012 to 11.88/10,000 population in 2021, with an average reduction in the annual percentage change of 4.5%. There were obvious spatial-temporal aggregation characteristics in hepatitis B cases, and a high-incidence area was located in eastern Fujian. Spatio-temporal scanning statistics revealed four levels of aggregation of hepatitis B reporting rates. The first level of aggregation area included Minhou, Gulou, Jin'an, Taijiang, and nine other districts and counties.

Conclusion

The incidence of hepatitis B is declining in Fujian Province. Spatial clusters of hepatitis B cases in Fujian Province were identified, and high-risk areas in eastern Fujian still exist. Closely monitoring the general patterns in the occurrence of hepatitis B and implementing focused control and preventative strategies are important.

Background

Swift and accurate detection of Vibrio parahaemolyticus, which is a prominent causative pathogen associated with seafood contamination, is required to effectively combat foodborne disease and wound infections. The toxR gene is relatively conserved within V. parahaemolyticus and is primarily involved in the expression and regulation of virulence genes with a notable degree of specificity. The aim of this study was to develop a rapid, simple, and constant temperature detection method for V. parahaemolyticus in clinical and nonspecialized laboratory settings.

Methods

In this study, specific primers and CRISPR RNA were used to target the toxR gene to construct a reaction system that combines recombinase polymerase amplification (RPA) with CRISPR‒Cas13a. The whole-genome DNA of the sample was extracted by self-prepared sodium dodecyl sulphate (SDS) nucleic acid rapid extraction reagent, and visual interpretation of the detection results was performed by lateral flow dipsticks (LFDs).

Results

The specificity of the RPA-CRISPR/Cas13a-LFD method was validated using V. parahaemolyticus strain ATCC-17802 and six other non-parahaemolytic Vibrio species. The results demonstrated a specificity of 100%. Additionally, the genomic DNA of V. parahaemolyticus was serially diluted and analysed, with a minimum detectable limit of 1 copy/µL for this method, which was greater than that of the TaqMan-qPCR method (10² copies/µL). The established methods were successfully applied to detect wild-type V. parahaemolyticus, yielding results consistent with those of TaqMan-qPCR and MALDI-TOF MS mass spectrometry identification. Finally, the established RPA-CRISPR/Cas13a-LFD method was applied to whole blood specimens from mice infected with V. parahaemolyticus, and the detection rate of V. parahaemolyticus by this method was consistent with that of the conventional PCR method.

Conclusions

In this study, we describe an RPA-CRISPR/Cas13a detection method that specifically targets the toxR gene and offers advantages such as simplicity, rapidity, high specificity, and visual interpretation. This method serves as a valuable tool for the prompt detection of V. parahaemolyticus in nonspecialized laboratory settings.

In a retrospective view, this review examines the impact of mucormycosis on health workers and researchers during the COVID era. The diagnostic and treatment challenges arising from unestablished underlying pathology and limited case studies add strain to healthcare systems. Mucormycosis, caused by environmental molds, poses a significant threat to COVID-19 patients, particularly those with comorbidities and compromised immune systems. Due to a variety of infectious Mucorales causes and regionally related risk factors, the disease's incidence is rising globally. Data on mucormycosis remains scarce in many countries, highlighting the urgent need for more extensive research on its epidemiology and prevalence. This review explores the associations between COVID-19 disease and mucormycosis pathology, shedding light on potential future diagnostic techniques based on the fungal agent's biochemical components. Medications used in ICUs and for life support in ventilated patients have been reported, revealing the challenge of managing this dual onslaught. To develop more effective treatment strategies, it is crucial to identify novel pharmacological targets through “pragmatic” multicenter trials and registries. In the absence of positive mycology culture data, early clinical detection, prompt treatment, and tissue biopsy are essential to confirm the specific morphologic features of the fungal agent. This review delves into the history, pathogens, and pathogenesis of mucormycosis, its opportunistic nature in COVID or immunocompromised individuals, and the latest advancements in therapeutics. Additionally, it offers a forward-looking perspective on potential pharmacological targets for future drug development.

Tuberculosis is a chronic infectious disease, caused by Mycobacterium tuberculosis, that seriously endangers human health. Skeletal tuberculosis is the most common type of extrapulmonary tuberculosis and tuberculous arthritis is the second most common type of skeletal tuberculosis. We report a case series of patients with tuberculous arthritis, two of whom had no joint disease in the past and presented as monoarthritis. The final patient had a history of rheumatoid arthritis, with polyarthritis that was aggravated during treatment with glucocorticoids and immunosuppressive drugs. This series of cases can contribute to early diagnosis and treatment with appropriate infection control measures.

Hand, foot, and mouth disease (HFMD) is one of the most common class C infectious diseases, posing a serious threat to public health worldwide. Enterovirus A71 (EV-A71) and coxsackievirus A16 (CV-A16) have been regarded as the major pathogenic agents of HFMD; however, since an outbreak caused by coxsackievirus A6 (CV-A6) in France in 2008, CV-A6 has gradually become the predominant pathogen in many regions. CV-A6 infects not only children but also adults, and causes atypical clinical symptoms such as a more generalized rash, eczema herpeticum, high fever, and onychomadesis, which are different from the symptoms associated with EV-A71 and CV-A16. Importantly, the rate of genetic recombination of CV-A6 is high, which can lead to changes in virulence and the rapid evolution of other characteristics, thus posing a serious threat to public health. To date, no specific vaccines or therapeutics have been approved for CV-A6 prevention or treatment, hence it is essential to fully understand the relationship between recombination and evolution of this virus. Here, we systematically review the genetic recombination events of CV-A6 that have occurred worldwide and explore how these events have promoted virus evolution, thus providing important information regarding future HFMD surveillance and prevention.

Background

Hand, foot, and mouth disease (HFMD) is a common childhood infectious disease caused by a variety of enteroviruses (EVs). To explore the epidemiological characteristics and etiology of HFMD in Zhengzhou, China, we conducted a systematic analysis of HFMD surveillance data from Zhengzhou Center for Disease Control and Prevention from January 2009 to December 2021 (https://wjw.zhengzhou.gov.cn/).

Methods

Surveillance data were collected from Zhengzhou Center for Disease Control and Prevention from January 2009 to December 2021 (https://wjw.zhengzhou.gov.cn/). Cases were analyzed according to the time of onset, type of diagnosis, characteristics, viral serotype, and epidemiological trends.

Results

We found that the primary causative agent responsible for the HFMD outbreaks in Zhengzhou was Enterovirus A71 (EVA-71) (48.56%) before 2014. After 2015, other EVs gradually became the dominant strains (57.68%). The data revealed that the HFMD epidemics in Zhengzhou displayed marked seasonality, with major peaks occurring from April to June, followed by secondary peaks from October to November, except in 2020. Both the severity and case-fatality ratio of HFMD decreased following the COVID-19 pandemic (severity ‰: 13.46 vs. 0.17; case-fatality ‰: 0.21 vs. 0, respectively). Most severe cases were observed in patients aged 1 year and below, accounting for 45.81%.

Conclusions

Overall, the incidence rate of HFMD decreased in Zhengzhou following the introduction of the EVA-71 vaccine in 2016. However, it is crucial to acknowledge that HFMD prevalence continues to exhibit a distinct seasonal pattern and periodicity, and the occurrence of other EV infections poses a new challenge for children's health.

Fusobacterium vincentii brain abscesses are relatively rare. Here, we report our treatment of an anaerobic brain abscess caused by a mixed infection of Parvimonas micra, Streptococcus constellatus, Fusobacterium vincentii, and Bacteroides heparinolyticus diagnosed by metagenomic next-generation sequencing (mNGS). This is the first reported case of Fusobacterium vincentii in a brain abscess. This case highlights the possibility that oral anaerobic microbes can cause a brain abscess and demonstrates that mNGS has the potential to be deployed to provide rapid infection diagnosis and rationalize antimicrobial therapy for brain abscesses.

Background

An epizootic of highly pathogenic avian influenza A (H5N1) has spread worldwide since 2022. Even though this virus has been extensively studied for many decades, little is known about its evolution in South America.

Methods

Here, we describe the sequencing and characterization of 13 H5N1 genomes collected from wild birds, poultry, and wild mammals in Peru during the genomic surveillance of this outbreak.

Results

The samples belonged to the highly pathogenic avian influenza (H5N1) 2.3.4.4b clade. Chilean and Peruvian samples clustered in the same group and therefore share a common ancestor. An analysis of the hemagglutinin and neuraminidase genes detected new mutations, some dependent upon the host type.

Conclusions

The genomic surveillance of highly pathogenic avian influenza is necessary to promote the One Health policy and to overcome the new problems entailed by climate change, which may alter the habitats of resident and migratory birds.