Opportunistic Infections Research Articles

The two alternative NADH:quinone oxidoreductases from Staphylococcus aureus: two players with different molecular and cellular roles.

Staphylococcus aureus is an opportunistic pathogen that has emerged as a major public health threat due to the increased incidence of its drug resistance. S. aureus presents a remarkable capacity to adapt to different niches due to the plasticity of its energy metabolism. In this work, we investigated the energy metabolism of S. aureus, focusing on the alternative NADH:quinone oxidoreductases, NDH-2s. S. aureus presents two genes encoding NDH-2s (NDH-2A and NDH-2B) and lacks genes coding for Complex I, the canonical respiratory NADH:quinone oxidoreductase. This observation makes the action of NDH-2s crucial for the regeneration of NAD+ and, consequently, for the progression of metabolism. Our study involved the comprehensive biochemical characterization of NDH-2B and the exploration of the cellular roles of NDH-2A and NDH-2B, utilizing knockout mutants (Δndh-2a and Δndh-2b). We show that NDH-2B uses NADPH instead of NADH, does not establish a charge-transfer complex in the presence of NADPH, and its reduction by this substrate is the catalytic rate-limiting step. In the case of NDH-2B, the reduction of the flavin is inherently slow, and we suggest the establishment of a charge transfer complex between NADP+ and FADH2, as previously observed for NDH-2A, to slow down quinone reduction and, consequently, prevent the overproduction of reactive oxygen species, which is potentially unnecessary. Furthermore, we observed that the lack of NDH-2A or NDH-2B impacts cell growth, volume, and division differently. The absence of these enzymes results in distinct metabolic phenotypes, emphasizing the unique cellular roles of each NDH-2 in energy metabolism.IMPORTANCEStaphylococcus aureus is an opportunistic pathogen, posing a global challenge in clinical medicine due to the increased incidence of its drug resistance. For this reason, it is essential to explore and understand the mechanisms behind its resistance, as well as the fundamental biological features such as energy metabolism and the respective players that allow S. aureus to live and survive. Despite its prominence as a pathogen, the energy metabolism of S. aureus remains underexplored, with its respiratory enzymes often escaping thorough investigation. S. aureus bioenergetic plasticity is illustrated by its ability to use different respiratory enzymes, two of which are investigated in the present study. Understanding the metabolic adaptation strategies of S. aureus to bioenergetic challenges may pave the way for the design of therapeutic approaches that interfere with the ability of the pathogen to successfully adapt when it invades different niches within its host.

Draft genome sequences for a Staphylococcus aureus and a Staphylococcus haemolyticus isolate from nasal swab samples from healthy females.

Staphylococcus aureus and Staphylococcus haemolyticus are common members of the human microbiota, but they are also opportunistic pathogens. To identify antibiotic resistance in healthy individuals, we present the genome sequences of S. aureus 139 N-1 and S. haemolyticus 173 N-3, both isolated from nasal swab samples from asymptomatic female participants.

HIV infection is associated with a less aggressive phenotype of inflammatory bowel disease. A multicenter study of the ENEIDA registry.

The coexistence of human immunodeficiency virus (HIV) infection and inflammatory bowel disease (IBD) is uncommon. Data on the impact of HIV on IBD course and its management is scarce. To describe the IBD phenotype, therapeutic requirements and prevalence of opportunistic infections (OI) in IBD patients with a coexistent HIV infection. Case-control, retrospective study including all HIV positive patients diagnosed with IBD in the ENEIDA registry. Patients with positive HIV serology (HIV-IBD) were compared to controls (HIV seronegative), matched 1:3 by year of IBD diagnosis, age, gender and type of IBD. A total of 364 patients (91 HIV-IBD and 273 IBD controls) were included. In the whole cohort, 58% had ulcerative colitis (UC), 35% had Crohn's disease (CD) and 7% were IBD unclassified. The HIV-IBD group presented a significantly higher proportion of proctitis in UC and colonic location in CD but fewer extraintestinal manifestations than controls. Regarding treatments, non-biological therapies (37.4% vs. 57.9%; P=0.001) and biologicals (26.4% vs. 42.1%; P=0.007), were used less frequently among patients in the HIV-IBD group. Conversely, HIV-IBD patients developed more OI than controls regardless of non-biological therapies use. In the multivariate analysis, HIV infection (OR 4.765, 95%CI 2.48-9.14; P<0.001) and having ≥1 comorbidity (OR 2.445, 95%CI 1.23-4.85; P=0.010) were risk factors for developing OI, while CD was protective (OR 0.372, 95%CI 0.18-0.78;P=0.009). HIV infection appears to be associated with a less aggressive phenotype of IBD and a lesser use of non-biological therapies and biologicals but entails a greater risk of developing OI.

Risk score prediction for bacteriologically confirmed tuberculosis among adults with HIV on antiretroviral therapy in northwest Ethiopia: prognostic model development.

This study was aimed at developing a risk score prediction model for bacteriologically confirmed tuberculosis (TB) among adults with HIV receiving antiretroviral therapy in Ethiopia. An institutional-based retrospective follow-up study was conducted among 569 adults with HIV on ART. We used demographic and clinical prognostic factors to develop a risk prediction model. Model performance was evaluated by discrimination and calibration using the area under the receiver operating characteristic (AUROC) curve and calibration plot. Bootstrapping was used for internal validation. A decision curve analysis was used to evaluate the clinical utility. Opportunistic infection, functional status, anemia, isoniazid preventive therapy, and WHO clinical stages were used to develop risk prediction. The AUROC curve of the original model was 87.53% [95% confidence interval (CI): 83.88-91.25] and the calibration plot ( P -value = 0.51). After internal validation, the AUROC curve of 86.61% (95% CI: 82.92-90.29%) was comparable with the original model, with an optimism coefficient of 0.0096 and good calibration ( P -value = 0.10). Our model revealed excellent sensitivity (92.65%) and negative predictive value (NPV) (98.60%) with very good specificity (70.06%) and accuracy (72.76%). After validation, accuracy (74.85%) and specificity (76.27%) were improved, but sensitivity (86.76%) and NPV (97.66%) were relatively reduced. The risk prediction model had a net benefit up to 7.5 threshold probabilities. This prognostic model had very good performance. Moreover, it had very good sensitivity and excellent NPV. The model could help clinicians use risk estimation and stratification for early diagnosis and treatment to improve patient outcomes and quality of life.

Epidemiology of cryptococcal meningitis and fluconazole heteroresistance in Cryptococcus neoformans isolates from a teaching hospital in southwestern China.

Cryptococcal meningitis (CM), a common and serious opportunistic infection mostly caused by Cryptococcus neoformans, is primarily treated with fluconazole. Nevertheless, Cryptococcus neoformans strains that undergo repeated exposure to azoles can gradually acquire heteroresistance to fluconazole. The management of this specific CM infection poses a substantial challenge. Determining a globally accepted definition for fluconazole heteroresistance and developing effective and prompt methods for identifying heteroresistance is of utmost importance. We collected data on the clinical and epidemiological characteristics of patients diagnosed with CM. All the available Cryptococcus neoformans strains isolated from these patients were collected and subjected to antifungal susceptibility testing and evaluation of fluconazole heteroresistance. AIDS was present in 40.5% of the patients, whereas 24.1% did not have any underlying diseases. Patients with chronic diseases or impaired immune systems are susceptible to infection by Cryptococcus neoformans, a fungus that frequently (39.6%, 19/48) shows heteroresistance to fluconazole, as confirmed by population analysis profile (PAP).IMPORTANCEFluconazole heteroresistance poses a significant threat to the efficacy of fluconazole in treating cryptococcal meningitis (CM). Unfortunately, the standard broth microdilution method often misses the subtle percentages of subpopulations exhibiting heteroresistance. While the population analysis profile (PAP) method is esteemed as the gold standard, its time-consuming and labor-intensive nature makes it impractical for routine clinical use. In contrast, the Kirby-Bauer (KB) disk diffusion method offers a simple and effective screening solution. Our study highlights the value of KB over PAP and minimum inhibitory concentration (MIC) by demonstrating that when adjusting the inoculum concentration to 1.0 McFarland and subjecting samples to a 72-hour incubation period at 35°C, the KB method closely mirrors the outcomes of the PAP approach in detecting fluconazole heteroresistance. This optimization of the KB method not only enhances assay efficiency but also provides a blueprint for developing a timely and effective strategy for identifying heteroresistance.

Duffy Antigen Receptor for Chemokines (DARC) Nanodisc-Based Biosensor for Detection of Staphylococcal Bicomponent Pore-Forming Leukocidins.

Staphylococcus aureus (S. aureus) is an opportunistic infectious pathogen, which causes a high mortality rate during bloodstream infections. The early detection of virulent strains in patients' blood samples is of medical interest for rapid diagnosis. The main virulent factors identified in patient isolates include leukocidins that bind to specific membrane receptors and lyse immune cells and erythrocytes. Duffy antigen receptor for chemokines (DARC) on the surface of specific cells is a main target of leukocidins such as gamma-hemolysin AB (HlgAB) and leukocidin ED (LukED). Among them, HlgAB is a conserved and critical leukocidin that binds to DARC and forms pores on the cell membranes, leading to cell lysis. Current methods are based on ELISA or bacterial culture, which takes hours to days. For detecting HlgAB with faster response and higher sensitivity, we developed a biosensor that combines single-walled carbon nanotube field effect transistors (swCNT-FETs) with immobilized DARC receptors as biosensing elements. DARC was purified from a bacterial expression system and successfully reconstituted into nanodiscs that preserve binding capability for HlgAB. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) showed an increase of the DARC-containing nanodisc size in the presence of HlgAB, indicating the formation of HlgAB prepore or pore complexes. We demonstrate that this sensor can specifically detect the leukocidins HlgA and HlgAB in a quantitative manner within the dynamic range of 1 fM to 100 pM with an LOD of 0.122 fM and an LOQ of 0.441 fM. The sensor was challenged with human serum spiked with HlgAB as simulated clinical samples. After dilution for decreasing nonspecific binding, it selectively detected the toxin with a similar detection range and apparent dissociation constant as in the buffer. This biosensor was demonstrated with remarkable sensitivity to detect HlgAB rapidly and has the potential as a tool for fundamental research and clinical applications, although this sensor cannot differentiate between HlgAB and LukED as both have the same receptor.

Balancing water conservation and health: do water-saving showerheads impact the microbes we breathe in during showering?

Low-flow showerheads offer consumers economic and water-saving benefits, yet their use may inadvertently affect the microbial content of produced water and water-associated aerosols. This study aimed to compare the abundance and microbial composition of bacteria in shower water and associated respirable aerosols produced by various low flow rate (1, 1.5, and 1.8 gpm) showerheads. Our findings indicate that the lowest-flow showerhead produces water with lower total microbial and opportunistic bacterial pathogen densities compared to higher low flow rate counterparts. However, microbiome analysis revealed that 1.8 gpm flow rate showerheads exhibit reduced abundance of Gram-negative organisms and common biofilm-forming organisms, suggesting potentially lower pathogenicity compared to 1 and 1.5 gpm low-flow showerheads. Additionally, the number of respirable aerosols produced by showerheads as well as the partitioning of certain microorganisms from the water to aerosol phases was negatively correlated with flow rate, suggesting that there may be increasing exposure potential to pathogenic bioaerosols when using a 1gpm showerhead compared to a 1.8 gpm showerhead. However, the 1.5 gpm showerhead seemed to balance microbial partitioning, aerosol generation, and water conservation. Moreover, the microbial composition of aerosols produced from shower water was more influenced by the age of the showerhead than the flow rate, highlighting the significance of biofilm formation on the microbial community. Overall, our findings underscore the importance of evaluating the microbial risk associated with low-flow showerheads using multiple metrics in both water and aerosols, and dynamically assessing this over time, to ensure accurate future risk assessment.

Characteristics of Pulmonary Tuberculosis patients with HIV in Regional General Hospital Dr Harjono Ponorogo period January 2018 – December 2022

Tuberculosis (TB) is the most common opportunistic infection in people living with HIV/AIDS in Indonesia, and HIV infection promotes Mycobacterium tuberculosis infection. In ODHIV, the probability of contracting TB is 10% per year. According to the Indonesian Ministry of Health, East Java is in second place with 71,909 cases and has the second highest number of AIDS patients and 824,000 TB cases in Indonesia. This study aims to determine the characteristics of pulmonary tuberculosis patients with HIV at DR Harjono Ponorogo Hospital for the period January 2018 - December 2022. This study applied descriptive research methodology with quantitative techniques with secondary data from medical records of pulmonary TB patients with HIV at Dr. Harjono Ponorogo Hospital for the period January 2018 - December 2022. The results showed a total sample of 130 medical records, there were several characteristics of TB patients with HIV, namely the highest age group of 30-39 years by 29.2%, more in male gender 73%. More patients had last high school education 38.5%, more treatment duration in patients who did for 9 months 61.5% and the results showed more patients with poor prognosis 56%. In conclusion, the characteristics of TB patients with HIV with the highest group at the age of 3-39 years, having male gender, more high school education, with more treatment duration of 9 months, and the results showed a poor prognosis.

Drinking Water Microbiota, Entero-Mammary Pathways, and Breast Cancer: Focus on Nontuberculous Mycobacteria

The prospect of drinking water serving as a conduit for gut bacteria, artificially selected by disinfection strategies and a lack of monitoring at the point of use, is concerning. Certain opportunistic pathogens, notably some nontuberculous mycobacteria (NTM), often exceed coliform bacteria levels in drinking water, posing safety risks. NTM and other microbiota resist chlorination and thrive in plumbing systems. When inhaled, opportunistic NTM can infect the lungs of immunocompromised or chronically ill patients and the elderly, primarily postmenopausal women. When ingested with drinking water, NTM often survive stomach acidity, reach the intestines, and migrate to other organs using immune cells as vehicles, potentially colonizing tumor tissue, including in breast cancer. The link between the microbiome and cancer is not new, yet the recognition of intratumoral microbiomes is a recent development. Breast cancer risk rises with age, and NTM infections have emerged as a concern among breast cancer patients. In addition to studies hinting at a potential association between chronic NTM infections and lung cancer, NTM have also been detected in breast tumors at levels higher than normal adjacent tissue. Evaluating the risks of continued ingestion of contaminated drinking water is paramount, especially given the ability of various bacteria to migrate from the gut to breast tissue via entero-mammary pathways. This underscores a pressing need to revise water safety monitoring guidelines and delve into hormonal factors, including addressing the disproportionate impact of NTM infections and breast cancer on women and examining the potential health risks posed by the cryptic and unchecked microbiota from drinking water.

Exploring the role of E. faecalis enterococcal polysaccharide antigen (EPA) and lipoproteins in evasion of phagocytosis.

Enterococcus faecalis is an opportunistic pathogen frequently causing nosocomial infections. The virulence of this organism is underpinned by its capacity to evade phagocytosis, allowing dissemination in the host. Immune evasion requires a surface polysaccharide produced by all enterococci, known as the enterococcal polysaccharide antigen (EPA). EPA consists of a cell wall-anchored rhamnose backbone substituted by strain-specific polysaccharides called 'decorations', essential for the biological activity of this polymer. However, the structural determinants required for innate immune evasion remain unknown, partly due to a lack of suitable validated assays. Here, we describe a quantitative, invitro assay to investigate how EPA decorations alter phagocytosis. Using the E. faecalis model strain OG1RF, we demonstrate that a mutant with a deletion of the locus encoding EPA decorations can be used as a platform strain to express heterologous decorations, thereby providing an experimental system to investigate the inhibition of phagocytosis by strain-specific decorations. We show that the aggregation of cells lacking decorations is increasing phagocytosis and that this process does not involve the recognition of lipoproteins by macrophages. Collectively, our work provides novel insights into innate immune evasion by enterococci and paves the way for further studies to explore the structure/function relationship of EPA decorations.

Comprehensive genomics reveals novel sequence types of multidrug resistant Klebsiella oxytoca with uncharacterized capsular polysaccharide K- and lipopolysaccharide O-antigen loci from the National Hospital of Uganda

The Klebsiella oxytoca complex comprises diverse opportunistic bacterial pathogens associated with hospital and community-acquired infections with growing alarming antimicrobial resistance. We aimed to uncover the genomic features underlying the virulence and antimicrobial resistance of isolates from Mulago National Hospital in Uganda. We coupled whole genome sequencing with Pathogenwatch multilocus sequence typing (MLST) and downstream bioinformatic analysis to delineate sequence types (STs) capsular polysaccharide K- and O-antigen loci, along with antimicrobial resistance (AMR) profiles of eight clinical isolates from the National Referral Hospital of Uganda. Our findings revealed that only two isolates (RSM6774 and RSM7756) possess a known capsular polysaccharide K-locus (KL74). The rest carry various unknown K-loci (KL115, KL128, KLI52, KL161 and KLI63). We also found that two isolates possess unknown loci for the lipopolysaccharide O-antigen (O1/O2v1 type OL104 and unknown O1). The rest possess known O1 and O3 serotypes. From MLST, we found four novel sequence types (STs), carrying novel alleles for the housekeeping genes glyceraldehyde-6-phosphate dehydrogenase A (gapA), glucose-6-phosphate isomerase (pgi), and RNA polymerase subunit beta (rpoB). Our AMR analysis revealed that all the isolates are resistant to ampicillin and ceftriaxone, with varied resistance to other antibiotics, but all carry genes for extended-spectrum beta-lactamases (ESBLs). Notably, one strain (RSM7756) possesses outstanding chromosomal and plasmid-encoded AMR to beta-lactams, cephalosporins, fluoroquinolones and methoprims. Conclusively, clinical samples from Mulago National Referral Hospital harbor novel STs and multidrug resistant K. oxytoca strains, with significant public health importance, which could have been underrated.

Nasal commensals reduce Staphylococcus aureus proliferation by restricting siderophore availability.

The human microbiome is critically associated with human health and disease. One aspect of this is that antibiotic-resistant opportunistic bacterial pathogens such as methicillin-resistant Staphylococcus aureus can reside within the nasal microbiota which increases the risk of infections. Epidemiological studies of the nasal microbiome have revealed positive and negative correlations between non-pathogenic species and S. aureus, but the underlying molecular mechanisms remain poorly understood. The nasal cavity is iron-limited and bacteria are known to produce iron-scavenging siderophores to proliferate in such environments. Siderophores are public goods that can be consumed by all members of a bacterial community. Accordingly, siderophores are known to mediate bacterial competition and collaboration but their role in the nasal microbiome is unknown. Here we show that siderophore acquisition is crucial for S. aureus nasal colonization in vivo. We screened 94 nasal bacterial strains from seven genera for their capacity to produce siderophores as well as to consume the siderophores produced by S. aureus. We found that 80% of the strains engaged in siderophore mediated interactions with S. aureus. Non-pathogenic corynebacterial species were found to be prominent consumers of S. aureus siderophores. In co-culture experiments, consumption of siderophores by competitors reduced S. aureus growth in an iron dependent fashion. Our data show a wide network of siderophore mediated interactions between the species of the human nasal microbiome and provide mechanistic evidence for inter-species competition and collaboration impacting pathogen proliferation. This opens avenues for designing nasal probiotics to displace S. aureus from the nasal cavity of humans.

Initiation of H1-T6SS dueling between Pseudomonas aeruginosa.

The Type VI secretion system (T6SS) is a multicomponent apparatus, present in many Gram-negative bacteria, which can inhibit bacterial prey in various ecological niches. Pseudomonas aeruginosa assembles one of its three T6SS (H1-T6SS) to respond to attacks from adjacent competing bacteria. Surprisingly, repeated assemblies of the H1-T6SS, termed dueling, were described in a monoculture in the absence of an attacker strain; however, the underlying mechanism was unknown. Here, we explored the role of H2-T6SS of P. aeruginosa in triggering H1-T6SS assembly. We show that H2-T6SS inactivation in P. aeruginosa causes a significant reduction in H1-T6SS dueling and that H2-T6SS activity directly triggers retaliation by the H1-T6SS. Intraspecific competition experiments revealed that elimination of H2-T6SS in non-immune prey cells conferred protection from H1-T6SS. Moreover, we show that the H1-T6SS response is triggered independently of the characterized lipase effectors of the H2-T6SS, as well as those of Acinetobacter baylyi and Vibrio cholerae. Our results suggest that H1-T6SS response to H2-T6SS in P. aeruginosa can impact intraspecific competition, particularly when the H1-T6SS effector-immunity pairs differ between strains, and could determine the outcome of multistrain colonization.IMPORTANCEThe opportunistic pathogen Pseudomonas aeruginosa harbors three different Type VI secretion systems (H1, H2, and H3-T6SS), which can translocate toxins that can inhibit bacterial competitors or inflict damage to eukaryotic host cells. Unlike the unregulated T6SS assembly in other Gram-negative bacteria, the H1-T6SS in P. aeruginosa is precisely assembled as a response to various cell damaging attacks from neighboring bacterial cells. Surprisingly, it was observed that neighboring P. aeruginosa cells repeatedly assemble their H1-T6SS toward each other. Mechanisms triggering this "dueling" behavior between sister cells were unknown. In this report, we used a combination of microscopy, genetic and intraspecific competition experiments to show that H2-T6SS initiates H1-T6SS dueling. Our study highlights the interplay between different T6SS clusters in P. aeruginosa, which may influence the outcomes of multistrain competition in various ecological settings such as biofilm formation and colonization of cystic fibrosis lungs.

Prevalence of co-trimoxazole resistance among HIV-infected individuals in Ethiopia: a systematic review and meta-analysis

BackgroundCo-trimoxazole is used as a prophylaxis for human immunodeficiency virus (HIV) patients to prevent opportunistic infections. Its widespread use results in the emergence of co-trimoxazole resistance, which is a significant problem. This systematic review and meta-analysis determined the pooled prevalence of co-trimoxazole resistance among HIV-infected individuals in Ethiopia.MethodsThe Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was applied to report this study. The protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the assigned number CRD42024532240. Article search was performed using electronic databases such as PubMed, Medline, EMBASE, Google Scholar, Hinari, Web of Science, Science Direct, and African Journals Online. Data were extracted using a Microsoft Excel spreadsheet and analyzed using STATA version 11.0 software. A random-effects model was used to estimate the pooled effect size of co-trimoxazole resistance across studies with a 95% confidence interval. The heterogeneity was checked using I2 statistic. The presence of publication bias was determined using a funnel plot and Egger’s test with a p-value &amp;lt;0.05 evidence of statistically significant bias. Subgroup and sensitivity analyses were performed.ResultsTwenty-two studies with 5,788 HIV-infected individuals were included. The pooled prevalence of co-trimoxazole resistance was 61.73% (95% CI: 53.10–70.37%), with heterogeneity (I2 = 87.7%) and statistical significance (p &amp;lt; 0.001). A higher co-trimoxazole resistance was observed in HIV-infected individuals with urinary tract infection; 82.10% (95% CI: 75.03–89.17%). Among the bacterial spp., higher resistance to co-trimoxazole was observed in Escherichia coli; 70.86% (95% CI: 53.44–88.27%) followed by Salmonella spp.; 67.66% (95% CI: 41.51–93.81%) and Proteus spp.; 66.23% (95% CI: 34.65–97.82%).ConclusionThere is a higher prevalence of co-trimoxazole resistance in HIV-infected individuals in Ethiopia. This alarms WHO’s recommendation of co-trimoxazole prophylaxis guidelines to review and update it. Additionally, a nationwide assessment of co-trimoxazole resistance in Ethiopia as a whole is required.Systematic review registration: identifier: CRD42024532240.

Study of Clinical Spectrum of Neurological Manifestations in HIV/AIDS Seen at Tertiary Referral Hospital in India

Objectives: The pandemic caused by human immunodeficiency virus (HIV) is one of the fastest growing health problems in the world today. Neurological manifestations of HIV infection and acquired immunodeficiency syndrome (AIDS) are being seen in a frequency that is parallel to the increasing number of new cases seen the world over. The World Health Organisation (WHO) estimates that 36.7 million people in the world are infected with HIV. Neurological manifestations of HIV disease can be seen in 20% of outpatients in HIV clinics and almost half of HIV patients being treated as in-patients. Of the various subtypes of HIV, subtype C is responsible for more than 50% of HIV1 infections causing rapidly growing epidemics in India. The objectives of this study were as follows: (1) To evaluate the prevalence of neurological manifestation in HIV-positive patients admitted to a tertiary referral Hospital in India. (2) To describe the neurological manifestations documented. (3) To find the possible predictors of neurological manifestations. Material and Methods: This study was a single centre prospective cross-sectional study in which out of 200 HIV/AIDS patients, 40 patients with neurological manifestations were analysed over a period of 18 months. They were interviewed and evaluated with particular reference to neurological manifestations, and were classified using the WHO staging system. Results: Amongst the studied population of 40 patients, 16 patients (40%) manifested as tuberculous meningitis (TBM) with or without brain tuberculomas, followed by seven patients (18%) presented with peripheral neuropathy and six patients (15%) presented with central nervous system (CNS) vasculitic or multi-infarct state. Cryptococcal meningitis was seen in five patients (12%), efavirenz-induced psychosis/seizure seen in one patient, while HIV-induced polymyositis, progressive multifocal leukoencephalopathy progressive multifocal leukoencephalopathy, acute inflammatory demylinating polyradiculoneuropathy, AIDS dementia complex and CNS toxoplasmosis were seen in one patient each respectively. One patient presented with dual opportunistic infection with coexistence of cryptococcal and tuberculous meningitis. Conclusion: Headache with or without vomiting, seizures and altered sensorium were the most common neurological symptoms. Fundus abnormalities, meningeal signs, gait abnormalities, cranial nerve dysfunction and hemiplegia were the most common neurological signs. New-onset headache was a significant predictor of the occurrence of neurological complications. Opportunistic infections such as TBM and Cryptococcal meningitis were most commonly observed.

Near-infrared spectroscopy and multivariate analysis as effective, fast, and cost-effective methods to discriminate Candida auris from Candida haemulonii

Candida auris and Candida haemulonii are two emerging opportunistic pathogens that have caused an increase in clinical cases in the recent years worldwide. The differentiation of some Candida species is highly laborious, difficult, costly, and time-consuming depending on the similarity between the species. Thus, this study aimed to develop a new, faster, and less expensive methodology for differentiating between C. auris and C. haemulonii based on near-infrared (NIR) spectroscopy and multivariate analysis. C. auris CBS10913 and C. haemulonii CH02 were separated in 15 plates per species, and three isolated colonies of each plate were selected for Fourier transform near-infrared (FT-NIR) analysis, totaling 90 spectra. Subsequently, principal component analysis (PCA) and variable selection algorithms, including the successive projections algorithm (SPA) and genetic algorithm (GA) coupled with linear discriminant analysis (LDA), were employed to discern distinctive patterns among the samples. The use of PCA, SPA, and GA algorithms associated with LDA achieved 100% sensitivity and specificity for the discriminations. The SPA-LDA and GA-LDA algorithms were essential in selecting the variables (infrared wavelengths) of most importance for the models, which could be attributed to binding of cell wall structures such as polysaccharides, peptides, proteins, or molecules resulting from yeasts’ metabolism. These results show the high potential of combined FT-NIR and multivariate analysis techniques for the classification of Candida-like fungi, which can contribute to faster and more effective diagnosis and treatment of patients affected by these microorganisms.

Torquetenovirus from bronchoalveolar lavage fluid as a biomarker for lung infection among immunocompromised hosts.

Aim: Torquetenovirus (TTV) was a promising biomarker for immunity, while lung regional TTV for evaluating the opportunistic infection among immunocompromised hosts (ICH) was unclear. Materials & methods: In the ICH and non-ICH populations, we compared the susceptibility to opportunistic infections, clinical severityand the prognosis between subgroups, respectively. Results: ICH with detectable bronchoalveolar lavage fluid (BALF)-TTV were more susceptible to lung aspergillosis and Mycobacterium infections. Furthermore, our data demonstrated that the ICH cohort with detectable BALF-TTV represented a higher clinical severity and a worse prognosis, while the above findings were not found in the non-ICH population. Conclusion: Our findings demonstrated that the BALF-TTV could act as an effective predictor for opportunistic infection for ICH that complemented the CD4+ T cell counts.

Alternative ergosterol biosynthetic pathways confer antifungal drug resistance in the human pathogens within the Mucor species complex.

The Mucor species complex comprises a variety of opportunistic pathogens known to cause mucormycosis, a potentially lethal fungal infection with limited therapeutic options. The only effective first-line treatments against mucormycosis consist of liposomal formulations of amphotericin B and the triazoles posaconazole and isavuconazole, all of which target components within the ergosterol biosynthetic pathway. This study uncovered M. circinelloides Erg3 and Erg6a as key enzymes to produce ergosterol, a vital constituent of fungal membranes. Absence of any of those enzymes leads to decreased ergosterol and consequently, resistance to ergosterol-binding polyenes such as amphotericin B. Particularly, losing Erg6a function poses a higher threat as the ergosterol pathway is channeled into alternative sterols similar to cholesterol, which maintain membrane permeability. As a result, erg6a mutants survive within the host and disseminate the infection, indicating that Erg6a deficiency may arise during human infections and confer resistance to the most effective treatment against mucormycoses.

Reverse Vaccinology Approach to Identify Novel and Immunogenic Targets against Streptococcus gordonii

Streptococcus gordonii is a gram-positive, mutualistic bacterium found in the human body. It is found in the oral cavity, upper respiratory tract, and intestines, and presents a serious clinical problem because it can lead to opportunistic infections in individuals with weakened immune systems. Streptococci are the most prevalent inhabitants of oral microbial communities, and are typical oral commensals found in the human oral cavity. These streptococci, along with many other oral microbes, produce multispecies biofilms that can attach to salivary pellicle components and other oral bacteria via adhesin proteins expressed on the cell surface. Antibiotics are effective against this bacterium, but resistance against antibodies is increasing. Therefore, a more effective treatment is needed. Vaccines offer a promising method for preventing this issue. This study generated a multi-epitope vaccine against Streptococcus gordonii by targeting the completely sequenced proteomes of five strains. The vaccine targets are identified using a pangenome and subtractive proteomic approach. In the present study, 13 complete strains out of 91 strains of S. gordonii are selected. The pangenomics results revealed that out of 2835 pan genes, 1225 are core genes. Out of these 1225 core genes, 643 identified as non-homologous proteins by subtractive proteomics. A total of 20 essential proteins are predicted from non-homologous proteins. Among these 20 essential proteins, only five are identified as surface proteins. The vaccine construct is designed based on selected B- and T-cell epitopes of the antigenic proteins with the help of linkers and adjuvants. The designed vaccine is docked against TLR2. The expression of the protein is determined using in silico gene cloning. Findings concluded that Vaccine I with adjuvant shows higher interactions with TLR2, suggesting that the vaccine has the ability to induce a humoral and cell-mediated response to treat and prevent infection; this makes it promising as a vaccine against infectious diseases caused by S. gordonii. Furthermore, validation of the vaccine construct is required by in vitro and in vivo trials to check its actual potency and safety for use to prevent infectious diseases caused by S. gordonii.

Atherosclerosis and HIV: Exploring Cardiovascular Risks and Management.

The advent of antiretroviral therapy has markedly improved the life expectancy of individuals with HIV, leading to a shift in clinical focus from managing opportunistic infections to addressing chronic conditions, such as atherosclerotic cardiovascular disease (ASCVD). Emerging evidence highlights an elevated risk of ASCVD among people living with HIV, characterized by a higher incidence of acute myocardial infarction, ischemic stroke, and heart failure compared with the general population. This review examines the epidemiology, pathophysiology, and management of ASCVD in the context of HIV. It explores the interplay between HIV infection, antiretroviral therapy, and traditional cardiovascular risk factors, underscoring the need for comprehensive cardiovascular risk reduction strategies tailored to people living with HIV. Through synthesizing data from clinical trials, observational studies, and basic research, the review aims to enhance understanding of HIV-associated ASCVD and inform healthcare practices to improve the longevity and quality of life for this patient population.