Diagnostic microbiology and infectious disease最新文献

Lomentospora prolificans is an uncommon cause of invasive fungal disease, but it is associated with high mortality because it is difficult to treat. Most of severe cases are produced in immunossupressed patients, especially in those with neutropenia and/or hematological malignancies. Resistance to the majority of antifungal agents can be still observed. Here we report two cases of L. prolificans fungemia with different outcome, since in one of these patients treatment with one of the new antifungals could be applied. Both patients were treated with different antifungal drugs, but only the second one survived due to therapy with fosmanogepix®. The current treatment is still based on a combination of conventional antifungal drugs, although in much cases this strategy is not sufficient. The introduction of new promising antifungal agents such as fosmanogepix® and olorofim® may open new perspectives in the treatment of invasive infections caused by L. prolificans, as in our patient.

Pure neuritic leprosy (PNL) is characterized by exclusive peripheral neuropathy without dermatological alterations. Diagnosis is difficult since skin lesions and acid-fast bacilli (AFB) in slit smears are absent. Presently, the gold standard for diagnosis is the histopathological examination of peripheral nerve biopsy. Even then, the detection of bacteria is difficult, and histological findings may be non-specific. Nerve biopsy is an invasive procedure that is possible only in specialized centers and limited to certain sensory nerves. Therefore, the establishment of serological, immunological, and molecular laboratory tests could be more beneficial for diagnosing pure neuritic leprosy to achieve effective treatment and reduction in its consequent disabilities. This review suggests that the presence of Mycobacterium leprae (M.leprae) in PNL cases can be proven by using non-invasive procedures, viz., multiplex polymerase chain reaction (M-PCR), serological findings, immunological profiling, and improved nerve-imaging. Findings also indicate the necessity for improving the sensitivity of PCR and further research on specificity in ruling out other clinical conditions that may mimic PNL.

Current guidelines recommend urine culture after catheter replacement to diagnose catheter-associated urinary tract infections (CA-UTI) in patients with long-term catheters, but it's unclear if this applies to short-term catheterizations. We studied 52 patients with catheters for less than 28 days, showing symptoms of CA-UTI. We collected urine from the catheter port initially and from the new catheter within 2 hours of replacement. Positive culture rates were 36.5 % before and 28.8 % after replacement. Significant differences in urine culture results were observed in 32.7 % of cases postreplacement (P = .0184), increasing to 78.9 % after excluding negative pre-replacement cultures (P = 0.0003). Duration of catheterization didn't affect urine bacteriology changes post-replacement. This suggests that urine bacteriology often differs after catheter replacement in short-term catheterizations.

This study investigated the diagnostic potential of targeted next-generation sequencing (tNGS) for pulmonary infections. The positivity rate of tNGS was significantly higher than that of traditional microbial culture (92.6 % vs 25.2 %, χ2 = 378.272, P < 0.001). The proportion of two or more species of pathogens detected using tNGS exceeded that detected using microbial culture (χ2 = 337.283, P < 0.001). There were inconsistencies between the results of the tNGS antibiotic resistance gene and the drug susceptibility test resistance phenotype. The tNGS technique demonstrates rapid and effective capabilities in identifying bacteria, fungi, viruses, and specific pathogens, with a detection sensitivity that surpasses that of conventional culture methodologies. Microbial drug resistance genotypes detected by tNGS cannot accurately predict drug resistance phenotypes and require further improvement or integration with traditional microbial culture to establish a foundation for effective clinical treatment.

The GenoType CMdirect Ver 1.0 and GenoType Mycobacterium Common Mycobacteria Ver 2.0-line probe assays were utilized to identify nontuberculous mycobacteria (NTM) from decontaminated sputum in a GeneXpert MTB/RIF Ultra negative cohort. A preliminary NTM prevalence of 1.7 % was observed, with a 100 % specificity. The high specificity advocates the CMdirect as a possible rule-in test for NTM disease.

Brucellosis is a zoonotic infectious disease widely seen worldwide, especially in developing countries and endemic regions where livestock farming is common. Brucella primarily affects the reticuloendothelial system and joints but can also localize in the central nervous, cardiovascular, and genitourinary systems. Pulmonary and urinary involvements are very rarely reported in the literature. This article presents a 24-year-old male patient who was admitted with syncope. Initially admitted with a preliminary diagnosis of Crimean-Congo hemorrhagic fever, the first thoracic computed tomography findings of the patient were considered alveolar hemorrhage. However, due to the growth of Brucella spp. in blood and urine cultures, the patient was diagnosed with necrotizing pneumonia due to brucellosis.

The diagnosis of Bartonella is challenging due to its rarity and negative culture results. Once the diagnosis is delayed and proper treatment is not given, it can develop into infective endocarditis, which can be fatal. We reported a 60-year-old female patient who had recurrent fever for 5 months. After receiving ineffective treatment at the local hospital, she sought medical attention at our hospital. Laboratory blood indicators testing and imaging indicated infective endocarditis, and metagenomic Next Generation Sequencing (m-NGS) testing confirmed the diagnosis of Bartonella vinsonii infection. After surgical treatment and the combination of doxycycline and ceftriaxone sodium for anti-infective therapy, the patient recovered. Valuing the combination of multiple auxiliary diagnostic methods and improving the application of m-NGS in the detection of unknown pathogens can compensate for the current limitations in the diagnosis of Bartonella. Early diagnosis and treatment are extremely important for Bartonella endocarditis.

Background

Invasive pneumococcal disease (IPD) remains a significant concern among children under 5, despite vaccination efforts. This study assessed IPD prevalence and associated risks in pediatric population.

Methods

An observational, retrospective, multicenter study in Comunidad Valenciana, Spain, of IPD cases in children under 13 from January 2012 to September 2022. Data from the CV Microbiology Surveillance Network (RedMIVA) and medical records were reviewed.

Results

A total of 379 IPD cases in 377 patients were analyzed, predominantly males (54.11 %) under 5 (81.17 %). PCV13 vaccination notably reduced PCV13-serotypes IPD (p=0.0002), except serotype 3. Pneumonia was common, with half having underlying conditions (50.40 %). Worse outcomes occurred in patients with neurological disorders (ANOVA, p=0.57). Vaccine failures often involved underlying conditions (63 %) and serotypes 3 and 19A. Immunodeficiencies may relate to recurrent IPD, but evidence is limited.

Conclusion

Despite vaccination, IPD still impacts children, influenced by immunological status, affecting severity and mortality.

Systemic bacterial infections represent a significant clinical challenge due to the increasing resistance rate towards antimicrobials. An essential key to controlling antimicrobial resistance spread is to administer targeted therapy after a precise minimum inhibitory concentration reporting. Among the available fast technologies for antimicrobial susceptibility testing (AST), the VITEK^Ⓡ REVEAL™ (Biomerieux, Florence, Italy) proposes volatile organic compounds (VOC) colourimetric arrays to discriminate between susceptible and resistant Gram-negative isolates directly from positive blood cultures. We evaluated this methodology during a four-month laboratory experience on 40 positive blood culture samples, reporting a comparison to standard culture-based methods. The protocol revealed an essential agreement of 100 % between the conventional and the experimental procedures, while the categorical agreement resulted in 97.5 % due to one very major error (VME) for meropenem/vaborbactam in K. pneumoniae. Although further studies will be necessary to investigate its performance on rare microorganisms, the VITEK^Ⓡ REVEAL™ demonstrated an optimal sensitivity in defining MIC values for multi-drug resistant (MDR) microorganisms. These results encourage the application of the method in all high-risk epidemiological areas, confirming the effectiveness of VOC detection in monitoring bacterial susceptibility profiles.