Annals of Clinical Microbiology and Antimicrobials最新文献

Immunopathology of human tuberculosis (TB) in a subgroup of patients is characterized by aberrantly high concentrations of inflammatory cytokines, for example Interleukin (IL)-6. Concomitant (co-)infections by parasites can affect host immunity, but the impact on immunopathology in TB patients is poorly defined. Here we characterized a group of patients with TB ( n = 76) from Ghana with different protozoan and helminth co-infections. Plasma cytokines were measured at the onset of disease and anti-mycobacterial treatment efficacy was monitored during disease course. A subgroup of TB patients had co-infections with protozoan (n = 19) or helminth (n = 16) parasites. Plasma analyses for candidate cytokines identified lower levels of IL-6 in parasite co-infected patients with TB. Moreover, it took less time for co-infected patients to become sputum-negative for Mycobacterium tuberculosis during treatment. These results indicated an influence of parasite co-infections on immunopathology in TB and suggested positive effects on treatment efficacy.

Purpose: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an emerging global threat, whereas its epidemiological characteristics in children are rarely reported. This study aims to analyze clinical and epidemiological characteristics of CRKP from children in Henan, China.

Methods: CRKP strains were isolated from pediatric patients, and the antimicrobial susceptibility of CRKP was determined using broth microdilution methods. The epidemiological characteristics of CRKP, including specimen sources, clinical data, carbapenemase types, virulence factors, MLST and PBRT typing were analyzed.

Results: In total, 108 CRKP isolates were isolated from specimens including sputum, blood and urine, mainly from preterm pediatric department and internal medical intensive care unit (ICU). Newborns and staying in the ICU were risk factors for crude mortality. 107 isolates exhibited a multi-drug resistant (MDR) phenotype, and one isolate was extensively drug-resistant (XDR). Bacterial susceptibility to colistin, tigecycline and trimethoprim/sulfamethoxazole was 98.10%, 78.50% and 91.43%, respectively. Carbapenemase bla_KPC (86.11%) was predominant, followed by bla_NDM (5.56%) and bla_IMP (2.78%). Two strains co-harbored bla_KPC-bla_NDM, one had bla_KPC-bla_IMP, whereas three isolates did not carry any of the analyzed carbapenemase genes. All strains possessed fimH, and 98% of the isolates possessed mrkD. Hypervirulent factors rmpA2 and iucA showed high positive rates (71.30% and 49.07%), with 48.15% of strains containing both genes. MLST analysis identified nine distinct sequence types (STs), with ST11 (82.41%) being the most common, followed by ST2154 (4.63%) and ST307 (3.70%). PBRT analysis revealed IncFII (85.19%) as the most prevalent plasmid.

Conclusion: In summary, this study reported the epidemiological features of CRKP in pediatric patients in Henan, China, highlighting the high prevalence of multi-drug-resistant and hypervirulent strains, and underscoring the significance of continuous surveillance.

Background: Multiple studies have demonstrated the utility of sonication to improve culture yield in patients with cardiovascular implantable electronic device (CIED) infections.

Objective: To analyze the usefulness of sonication in the microbiological diagnosis of CIED infections in comparison with traditional cultures.

Methods: Systematic database searches were performed to identify studies that provided enough data concerning both sensitivity and specificity of traditional (non-sonicated) and sonicated cultures from CIED samples. The diagnostic accuracy measures were obtained by three different statistical approaches: (i) The univariate model; (ii) The bivariate random; and (iii) The Bayesian bivariate hierarchical model. Heterogeneity was assessed using meta-regression.

Findings: Nine studies met the criteria for inclusion in the meta-analysis (1684 cultures). The summary estimates of sensitivity were higher for sonicated cultures (0.756) in comparison with non-sonicated cultures (0.446). On meta-regression, sonication of CIEDs significantly increased the sensitivity (p = 0.001) as well as the rates of false positive results (p = 0.003). The final model also showed that the studies that used a threshold for positivity were associated with lower rates of false positive results (p < 0.001).

Interpretation: Our results suggest that sonication improves the microbiological diagnosis of CIED infections in comparison with traditional cultures, but a standardization of processes is necessary.

Background: It is presently considered that Corynebacterium especially Corynebacterium kroppenstedtii (CK) infection, is one of the important causes of granulomatous lobular mastitis (GLM). However, the pathogen of mastitis in the past two years has been identified as a newly discovered Corynebacterium. But it is unclear whether the pathogen associated with the occurrence of GLM is also this bacterium.

Methods: GLM female patients with positive bacterial culture in pus specimens from February 2023 to February 2024 who were identified as CK infection by mass spectrometer were selected as the research objects in this study, and the clinical isolates were identified by 16S rDNA sequencing technology to identify the specific pathogen of GLM-related bacterial infection. Subsequently, the clinical characteristics of the patients were compared with those of GLM patients without bacterial infection during the same period, to explore the effect of this particular type of Corynebacterium infection on disease development in GLM patients. Finally, we tested the minimum inhibitory concentration (MIC) values of antibiotics when inhibiting these separation strains in vitro through the E-Test experiment, to evaluate their medicine sensitivity.

Results: A total of 31 GLM patients initially diagnosed with Corynebacterium kroppenstedtii (CK) infection via MALDI-TOF MS were enrolled in the study. However, subsequent 16S rDNA sequencing revealed that 28 isolates (90.32%) were actually identified as the newly recognized Corynebacterium parakroppenstedtii (CPK). This discovery challenges the conventional belief that CK is the primary pathogen of GLM, suggesting instead that CPK is the predominant pathogen associated with GLM bacterial infections. Comparative analysis of the clinical characteristics between the two groups revealed a significantly higher recurrence rate among CPK-infected GLM patients compared to those without CPK infection, along with elevated prolactin levels (P < 0.05). The sensitivity test results indicated high sensitivity of the isolates to vancomycin, linezolid, and rifampicin.

Conclusion: In conclusion, this study highlights that Corynebacterium kroppenstedtii strains isolated from GLM specimens were Corynebacterium parakroppenstedtii, serving as the primary pathogen closely linked to GLM's occurrence. CPK infection significantly increases the risk of recurrence in GLM patients, with elevated prolactin levels potentially playing a pivotal role in this process. In clinical antimicrobial treatment, antimicrobials other than penicillin and ciprofloxacin may be empirically administered when sensitivity test results are inconclusive.

Objective: This study aims to present a case of persistent mycetoma caused by Scedosporium boydii and undertake a systematic literature overview to elucidate the clinical characteristics and antifungal treatment exhibited by such patients.

Methods: We report the case of a 24-year-old female who sustained a Scedosporium boydii infection in her right foot over a decade ago following a nail puncture. Concurrently, a comprehensive literature overview was conducted on PubMed, focusing on documented cases of Scedosporium boydii infections with the intent of extracting relevant clinical data.

Results: Our analysis revealed that post-transplantation, trauma, near drowning, corticosteroid administration, and prior surgical history were the main risk factors for Scedosporium boydii infection. Prevalent infection sites included skin/bone tissues, the central nervous system, and ocular regions. Among the 49 patients identified, 24 received itraconazole therapy and 25 received voriconazole, with no significant difference in patient outcomes (P = 0.158). Of these, 12 patients experienced treatment failure. Notably, prolonged antifungal treatment duration was identified as a protective factor against mortality in Scedosporium boydii infections [P = 0.022, OR(95%CI): 0.972(0.949-0.996)]. Conversely, a history of post-transplantation emerged as a potential risk factor for mortality[P = 0.046, OR(95%CI): 7.017(1.034-47.636)].

Conclusion: While uncommon, Scedosporium boydii infections carry a significant burden of morbidity and adverse outcomes. Heightened clinical vigilance is warranted in individuals presenting with risk factors for this pathogen. Timely and effective antifungal intervention is crucial, with both voriconazole and itraconazole demonstrating positive treatment outcomes for Scedosporium boydii infection. Therefore, prioritizing these antifungal agents should be considered a key therapeutic strategy in the management of this patient population.

Background: Determination of SARS-CoV-2 variant is significant to prevent the spreads of COVID-19 disease.

Methods: We aimed to evaluate the variants of SARS-CoV-2 rate in positive patients in Kanuni Sultan Suleyman Training and Research Hospital (KSS-TRH), Istanbul, Türkiye between 1st January and 30th November 2021 by using RT-PCR method.

Results: Herein, 825,169 patients were evaluated (male:58.53% and female:41.47%) whether COVID-19 positive or not [( +):21.3% and (-):78.7%] and 175,367 patient was described as positive (53.2%-female and 46.8%-male) by RT-PCR. COVID-19 positive rate is observed highest in the 6-15- and 66-75-year age range. The frequencies were obtained as SARS-CoV-2 positive (without mutation of B.1.1.7 [B.1.1.7 (U.K), E484K, L452R, B.1.351 (S. Africa/Brazil) spike mutations] as 66.1% (n: 115,899), B.1.1.7 Variant as 23.2% (n:40,686), Delta mutation (L452R) variant as 9.8% (n:17,182), B.1.351 variant as 0.8% (n:1370) and E484K as 0.1% (n: 230). In April 2021, general SARS-CoV-2 and B.1.1.7 variant were dominantly observed. Up to July 2021, B.1.617.2 (Delta variant/ Indian variant) and E484K has been not observed. B.1.351 variant of SARS-CoV-2 has been started in February 2021 at the rarest ratio and March 2021 is the top point. September 2021 is the pick point of E484K. African/Brazil variant of SARS-CoV-2 has been started in February 2021 at the rarest ratio and March 2021 is the top point. September 2021 is the pick point of E484K. When the gender type is compared within the variants, women were found to be more prevalent in all varieties.

Conclusions: The meaning of these mutations is very important to understand the transmission capacity of the COVID-19 disease, pandemic episode, and diagnosis of the virus with mutation types. Understanding the variant type is important for monitoring herd immunity and the spread of the disease.

Introduction: Gram-negative bacteremia is a life-threatening infection with high morbidity and mortality. Its incidence is rising worldwide, and treatment has become more challenging due to emerging bacterial resistance. Little data is available on the burden and outcome of such infections in Lebanon.

Methods: We conducted this retrospective study in four Lebanese hospitals. Data on medical conditions and demographics of 2400 patients diagnosed with a bloodstream infection based on a positive blood culture were collected between January 2014 and December 2020.

Results: Most bacteremias were caused by Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii, with the more resistant organisms being hospital-acquired. Third-generation cephalosporin and quinolone resistance was steady throughout the study, but carbapenem resistance increased. Mortality with such infections is high, but carbapenem resistance or infection with Pseudomonas or Acinetobacter species were significant risk factors for poor outcomes.

Conclusion: This is the first multi-center study from Lebanon on gram-negative bacteremia, resistance patterns, and factors associated with a poor outcome. More surveillance is needed to provide data to guide empirical treatment for bacteremia in Lebanon.

Background: Pediatric patients are vulnerable to the threat of carbapenem-resistant Klebsiella pneumoniae (CRKP) due to their limited immunity and few available antibiotics. Especially when these pathogens exhibit hypervirulent phenotypes, they are often associated with poor clinical outcomes.

Methods: In this study, we investigated a CRKP outbreak in pediatric patients from 2019 to 2021 in a teaching hospital in China based on whole genome sequencing. We sequenced twenty-nine CRKP isolates isolated from unduplicated pediatric patients to understand their genetic relationships, virulence factors, resistance mechanisms, and transmission trajectories. Conjugation experiments were performed to evaluate the horizontal transfer ability of carbapenem resistance determinants in twenty-nine CRKP isolates. We then characterized these isolates for biofilm formation ability and serum resistance. Genetic relatedness, comparison of plasmids, and chromosomal locus variation of CRKP isolates were analyzed by bioinformatics.

Results: All the isolates were carbapenemase-producers harbouring bla_NDM-5. Among them, twenty-eight isolates belonged to the ST2407 group, with the consistent capsular serotype K25. The virulence-related factors: ureA, fim, ybtA, irp1/irp2, and mrkA were prevalent in these isolates. Additionally, most CRKP isolates showed moderately adherent biofilm formation. Although the ST2407 clonal group did not exhibit serum resistance, the heterogeneous level of serum resistance was related to the disruption of oqxR. Conjugation and WGS revealed that the bla_NDM-5 carried by the twenty-eight CRKP ST2407 isolates was located on nonconjugative IncX3 plasmids associated with deleting the T4SS-encoding genes. Clonal transmission of CRKP ST2407 in pediatric patients was suggested by the phylogenetic tree.

Conclusions: Our study provides evidence of the clonal spread of bla_NDM-5-producing K. pneumoniae in pediatric patients and the necessity for the T4SS system for horizontal transfer of the IncX3 plasmid carrying bla_NDM-5. Additionally, the disruption of oqxR may have affected the serum resistance of CRKP. The results of this study emphasize the importance of continuously monitoring for CRKP infection in pediatric patients to prevent recurrent infections.

Background: The World Health Organization predicted 10.6 million new tuberculosis cases and 1.5 million deaths in 2022. Tuberculous meningitis, affecting 1% of active TB cases, is challenging to diagnose due to sudden onset, vague symptoms, and limited laboratory tests. Nanopore-targeted sequencing (NTS) is an emerging third-generation sequencing technology known for its sequencing capabilities. We compared its detection efficiency with Xpert, MTB culture, PCR, and AFB smear in cerebrospinal fluid samples to highlight the substantial potential of NTS in detecting intracranial tuberculosis.

Methods: This study included 122 patients suspected of having intracranial tuberculosis at the Second Hospital of Nanjing in Jiangsu Province, China, between January 2021 and January 2024. The Univariate logistic regression and random forest regression identified risk factors and clinical markers. A chi-square test evaluated diagnostic accuracy for different image types of intracranial tuberculosis.

Results: The research involved 100 patients with intracranial tuberculosis. Among them, 41 had tuberculous meningitis, 27 had cerebral parenchymal tuberculosis, and 32 had mixed intracranial tuberculosis. Besides, 22 patients were diagnosed with other brain conditions. In diagnosing intracranial tuberculosis, NTS demonstrated a sensitivity of 60.0% (95% CI: 49.7-69.5%) and a specificity of 95.5% (95% CI:75.1-99.8%), with an AUC value of 0.78 (95% CI: 0.71 to 0.84), whose overall performance was significantly better than other detection methods. There was no notable difference (P > 0.05) in diagnostic accuracy between NTS and the final diagnosis for intracranial tuberculosis patients with varying imaging types. Furthermore, patients who tested positive had a 31.500 (95% CI: 6.205-575.913) times higher risk of having intracranial tuberculosis compared to those with negative results.

Conclusion: Due to its convenience, efficiency, quick turnaround time, and real-time sequencing analysis, NTS might become a promising and reliable method for providing microbiological diagnoses for patients with intracranial tuberculosis and for screening populations at risk.

Introduction and purpose: Mycobacterium (M.) chelonae is responsible for a half of relatively rare nontuberculous mycobacteria (NTM) keratitis. We report a case of M. chelonae keratitis in a woman following sclerocorneal suture extraction after cataract surgery.

Results: A 70-year-old woman presented with a red eye and corneal infiltration of her left eye six weeks following sclerocorneal suture extraction after an elective cataract surgery in another institute. She complained of a sharp, cutting pain and photophobia. Since initial corneal scrapes and conjunctival swabs proved no pathogen using culture and PCR methods, non-specific antibiotics and antifungal agents were administered. As keratitis was complicated by an inflammation in the anterior chamber and vitreous, samples of the vitreous fluid were sent for microbiologic examination. DNA of Epstein-Barr virus (EBV) was repeatedly detected. Since the intrastromal abscess had formed, corneal re-scrapings were performed and M. chelonae was detected using culture, MALDI-TOF MS and PCR methods. Therapy was changed to a combination of oral and topical clarithromycin, intravitreal, topical and intracameral amikacin, and oral and topical moxifloxacin. The successful therapy led to stabilization. The optical penetrating keratoplasty was performed and no signs of the infection recurrence were found.

Conclusions: The diagnosis of nontuberculous mycobacterial keratitis is difficult and often delayed. An aggressive and prolonged antimicrobial therapy should include systemic and topical antibiotics. Surgical intervention in the form of corneal transplantation may be required in the active and nonresponsive infection. In the presented case this was necessary for visual rehabilitation due to scarring.