International Journal of Medical Microbiology最新文献

Background

To analysis of quasispecies (QS) changes and high-frequency mutations in the BCP/PreC/C region of patients at different phases of hepatitis B virus (HBV) infection and provides novel biomarkers for the diagnosis of chronic hepatitis B (CHB) patients.

Methods

With the application of next-generation sequencing technology, we were able to sequence the HBV BCP/PreC/C regions in 40 patients, each at different phases of the HBV infection. The heterogeneity of QS and the frequency of mutations were calculated using MEGA 7 software.

Results

Our results show that the complexity and diversity of the BCP/PreC/C QS in HBeAg-positive CHB patients are significantly higher than those in HBeAg-positive chronic infection patients, while HBeAg-negative chronic infection patients had significantly higher QS complexity and diversity than HBeAg-negative CHB patients. In addition, HBeAg-negative patients showed reduced complexity but increased diversity compared with HBeAg-positive patients. Receiver operating characteristic curves showed that G1764A, C2102T, dN and complexity of QS could be used as potential biomarkers for diagnosing HBeAg-positive CHB, while the A2189C, dS and complexity of QS could be used as potential biomarkers for diagnosing HBeAg-negative chronic hepatitis. Finally, our study also found that G1896A and A2159G may be hotspot mutations affecting HBeAg seroconversion.

Conclusion

Our research elucidates the evolution of HBV by analyzing QS heterogeneity and mutation patterns, offering novel serum biomarkers for enhancing clinical diagnosis and disease prognosis. This comprehensive approach sheds light on the intricate dynamics of HBV progression and paves the way for more precise medical interventions.

Nontypeable Haemophilus influenzae (NTHi) is the dominant pathogen in several infectious diseases. Currently the use of antibiotics is the main intervention to prevent NTHi infections, however with the emergence of drug resistant strains, it has compromised the treatment of respiratory infections with antibiotics. Therefore there is an urgent need to develop a safe and effective vaccine to prevent NTHi infections. We investigate the potential of C-HapS-P6 fusion protein as a vaccine for treating NTHi in murine models. PGEX-6P2/C-HapS-P6 fusion gene was constructed using overlap extension polymerase chain reaction. The recombined plasmid was transformed into Escherichia coli for protein expression. The mice were subjected to intraperitoneal immunization using purified antigens. Immunoglobulin (Ig) G in serum samples and IgA in nasal and lung lavage fluids were analyzed using enzyme-linked immunosorbent assay. Cytokine release and proliferation capacity of splenic lymphocytes in response to antigens were measured in vitro. The protective effect of the C-HapS-P6 protein against NTHi infection was evaluated by NTHi count and histological examination. The data showed that the C-HapS-P6 fusion protein increased significantly the levels of serum IgG and nasal and lung IgA, and promoted the release of interleukin (IL)-2, interferon-ϒ, IL-4, IL-5, and IL-17 and the proliferation of splenic lymphocytes compared with C-HapS or P6 protein treatment alone. Moreover, C-HapS-P6 effectively reduced the NTHi colonization in the nasopharynx and lungs of mice. In conclusion, our results demonstrated that the C-HapS-P6 fusion protein vaccine can significantly enhance humoral and cell immune responses and effectively prevent against NTHi infection in the respiratory tract in murine models.

Background

Talaromyces marneffei (T. marneffei) is a thermal dimorphic fungus, which can cause lung or blood stream infection in patients, often life-threatening. However, endocarditis caused by T. marneffei has not been reported. For elderly patients with implanted cardiac devices or artificial valves, the prevention and treatment of infective endocarditis should not be ignored.

Methods

This is a descriptive study of a T. marneffei endocarditis by joint detection of cardiac ultrasound examination, peripheral blood DNA metagenomics Next Generation Sequencing (mNGS), and in vitro culture.

Results

We describe an 80-year-old female patient with an unusual infection of T. marneffei endocarditis. After intravenous drip of 0.2 g voriconazole twice a day for antifungal treatment, the patient showed no signs of improvement and their family refused further treatment.

Conclusion

Infective endocarditis is becoming more and more common in the elderly due to the widely use of invasive surgical procedures and implantation of intracardiac devices. The diagnosis and treatment of T. marneffei endocarditis is challenging because of its rarity. Here, we discussed a case of T. marneffei endocarditis, and emphasized the role of mNGS in early diagnosis, which is of great significance for treatment and survival rate of patients.

Cryptococcosis is the most prevalent fungal infection of the central nervous system worldwide. We performed a retrospective multicenter cohort study to gain insights into the epidemiology of cryptococcosis in Germany. We describe the use of diagnostic tests, clinical management and patient outcome. We included 64 patients with underlying HIV infection (55%) or other predispositions. Molecular typing by MLST documented 20 individual sequence types among 42 typed isolates. A fatal outcome was documented in 14% of patients in the first two months after diagnosis.

Across the globe, hand hygiene (HH) is promoted to fight the spread of healthcare associated infections. Despite multiplongoing HH campaigns and projects, the healthcare associated infection rates remain high especially in low- and middle-income countries. In the narrative overview presented here, we aim to share objectives, framework, successes and challenges of our long-term partnership in Guinea to offer guidance for other projects aiming to sustainably improve HH.

Measles and rubella are targeted for elimination in the WHO region Europe. To reach the elimination goal, vaccination coverage of 95% must be achieved and sustained, the genotype information has to be provided for 80% of all outbreaks and transmission chains of a certain variant must not be detected for >12 months. The latter information is collected at Germany’s National Reference Center Measles, Mumps, Rubella (NRC MMR).

We describe here an outbreak of measles occurring in Hildesheim. The outbreak comprised 43 cases and lasted 14 weeks. Surprisingly, a high number of vaccination failures was observed since 11 cases had received two doses of the MMR vaccine and 4 additional cases were vaccinated once.

A 33-year-old woman passed away during the outbreak. She was the mother of 5 children between 4 and 16 years of age. Two schoolchildren contracted measles and passed it on to the rest of the family. Due to delivery bottlenecks, the vaccination of the mother was delayed. She developed measles-like symptoms 3 days after vaccination and was found dead on the morning of day 8 after vaccination. A post-mortem examination was done to identify the cause of death. Moreover, molecular characterization of the virus was performed to analyze whether she was infected by the wildtype virus circulating at that time in Hildesheim or whether the vaccine may have been a concomitant and aggravating feature of her death.

The result showed that the samples taken from her at the time of death and during necropsy contained the wildtype measles virus variant corresponding to MVs/Gir Somnath.IND/42.16 (WHO Seq-ID D8–4683) that fueled the Hildesheim outbreak and circulated in Germany from March 2018 to March 2020. The vaccine virus was not detected. Moreover, two aspects uncovered by the post-mortem examination were remarkable; the woman died from giant cell pneumonia, which is a complication seen in immune-suppressed individuals and she was actively using cannabis. THC is known to influence the immune system, but literature reports describing the effects are limited.

Shiga toxin-producing E. coli (STEC), including the subgroup of enterohemorrhagic E. coli (EHEC), are important bacterial pathogens which cause diarrhea and the severe clinical manifestation hemolytic uremic syndrome (HUS). Genomic surveillance of STEC/EHEC is a state-of-the-art tool to identify infection clusters and to extract markers of circulating clinical strains, such as their virulence and resistance profile for risk assessment and implementation of infection prevention measures. The aim of the study was characterization of the clinical STEC population in Germany for establishment of a reference data set. To that end, from 2020 to 2022 1257 STEC isolates, including 39 of known HUS association, were analyzed and lead to a classification of 30.4 % into 129 infection clusters. Major serogroups in all clinical STEC analyzed were O26, O146, O91, O157, O103, and O145; and in HUS-associated strains were O26, O145, O157, O111, and O80. stx1 was less frequently and stx2 or a combination of stx, eaeA and ehxA were more frequently found in HUS-associated strains. Predominant stx gene subtypes in all STEC strains were stx1a (24 %) and stx2a (21 %) and in HUS-associated strains were mainly stx2a (69 %) and the combination of stx1a and stx2a (12.8 %). Furthermore, two novel O-antigen gene clusters (RKI6 and RKI7) and strains of serovars O45:H2 and O80:H2 showing multidrug resistance were detected. In conclusion, the implemented surveillance tools now allow to comprehensively define the population of clinical STEC strains including those associated with the severe disease manifestation HUS reaching a new surveillance level in Germany.