Opportunistic Infections Research Articles

Multiplexed real-time PCR for the detection and differentiation of Klebsiella pneumoniae O-antigen serotypes.

Klebsiella pneumoniae has emerged as a global health threat due to its role in the spread of antimicrobial resistance and because it is a frequent cause of hospital-acquired infections and neonatal sepsis. Capsular and lipopolysaccharide (LPS) O-antigen polysaccharide surface antigens are major immunogens that are useful for strain classification and are candidates for vaccine development. We have developed real-time PCR reagents for molecular serotyping, subtyping, and quantitation of the most prevalent LPS O-antigen types (i.e., O1, O2, O3, and O5) of Klebsiella pneumoniae. We describe two applications for this O-typing assay: for screening culture isolates and for direct typing of Klebsiella pneumoniae present in stool samples. We find 100% concordance between the results of the O-typing assay and whole-genome sequencing of 81 culture isolates, and >90% agreement in O-typing performed directly on specimens of human stool, with disagreement arising primarily from a lack of sensitivity of the culture-based comparator method. Additionally, we find evidence for mixed O-type populations at varying levels of abundance in direct tests of stool from a hospitalized patient population. Taken together, these results demonstrate that this novel O-typing assay can be a useful tool for K. pneumoniae epidemiologic and vaccine studies.IMPORTANCEKlebsiella pneumoniae is an important opportunistic pathogen. The gastrointestinal (GI) tract is the primary reservoir of K. pneumoniae in humans, and GI carriage is believed to be a prerequisite for invasive infection. Knowledge about the dynamics and duration of GI carriage has been hampered by the lack of tools suitable for detection and strain discrimination. Real-time PCR is particularly suited to the higher-throughput workflows used in population-based studies, which are needed to improve our understanding of carriage dynamics and the factors influencing K. pneumoniae colonization.

Epidemiology and Clinical Features of Burkholderia Bacteremia at a Hospital in India.

Burkholderia spp. are opportunistic pathogens that cause infection in patients with disrupted immunity. The study intended to demonstrate the epidemiology and clinical features associated with Burkholderia spp. bacteremia. This retrospective study was performed to assess the clinical and laboratory characteristics of patients whose blood cultures were growing Burkholderia spp. and, based on their underlying comorbidities, were subjected to survival analysis from January 2022 to December 2022 at a university hospital in northern India. Three hundred patients with Burkholderia spp. bacteremia were included in this study conducted over 1 year. The mean age of the patients was 33.86 years with a male predominance of 56.67% (170/300, 56.67%). Underlying malignancies (207/300, 69.0%) were the most common clinical diagnosis, and catheter in situ (300/300, 100.0%) was the most common risk factor. Burkholderia cenocepacia (244/300, 81.33%) was the most common Burkholderia spp. isolated. All isolates were highly susceptible to minocycline. Kidney disease (P = 0.029), hypertension (P = 0.005), type 2 diabetes mellitus (P = 0.039), and respiratory disease (P <0.001) in patients were significantly associated with death owing to Burkholderia spp. bacteremia, whereas patients with malignancies (P <0.001) and undergoing treatment were significantly associated with a better outcome when the microorganism was susceptible to empirical antibiotics. The presence of indwelling devices, mechanical ventilation (P <0.001), and a hemodialysis catheter (P = 0.026) were statistically significant risk factors associated with poor outcomes.

Metabolic changes associated with polysaccharide utilization reduce susceptibility to some β-lactams in Bacteroides thetaiotaomicron.

Antibiotic therapy alters bacterial abundance and metabolism in the gut microbiome, leading to dysbiosis and opportunistic infections. Bacteroides thetaiotaomicron (Bth) is both a commensal in the gut and an opportunistic pathogen in other body sites. Past work has shown that Bth responds to β-lactam treatment differently depending on the metabolic environment both in vitro and in vivo. Studies of other bacteria show that an increase in respiratory metabolism independent of growth rate promotes susceptibility to bactericidal antibiotics. We propose that Bth enters a protected state linked to an increase in polysaccharide utilization and a decrease in the use of simple sugars. Here, we apply antibiotic susceptibility testing, transcriptomic analysis, and genetic manipulation to characterize this polysaccharide-mediated tolerance (PM tolerance) phenotype. We found that a variety of mono- and disaccharides increased the susceptibility of Bth to several different β-lactams compared to polysaccharides. Transcriptomics indicated a metabolic shift from reductive to oxidative branches of the tricarboxylic acid cycle on polysaccharides. Accordingly, supplementation with intermediates of central carbon metabolism had varying effects on PM tolerance. Transcriptional analysis also showed a decrease in the expression of the electron transport chain (ETC) protein NQR and an increase in the ETC protein NUO, when given fiber versus glucose. Deletion of NQR increased Bth susceptibility while deletion of NUO and a third ETC protein NDH2 had no effect. This work confirms that carbon source utilization modulates antibiotic susceptibility in Bth and that anaerobic respiratory metabolism and the ETC play an essential role.IMPORTANCEAntibiotics are indispensable medications that revolutionized modern medicine. However, their effectiveness is challenged by a large array of resistance and tolerance mechanisms. Treatment with antibiotics also disrupts the gut microbiome which can adversely affect health. Bacteroides are prevalent in the gut microbiome and yet are frequently involved in anaerobic infections. Thus, understanding how antibiotics affect these bacteria is necessary to implement proper treatment. Recent work has investigated the role of metabolism in antibiotic susceptibility in distantly related bacteria such as Escherichia coli. Using antibiotic susceptibility testing, transcriptomics, and genetic manipulation, we demonstrate that polysaccharides reduce β-lactam susceptibility when compared to monosaccharides. This finding underscores the profound impact of metabolic adaptation on the therapeutic efficacy of antibiotics. In the long term, this work indicates that modulation of metabolism could make Bacteroides more susceptible during infections or protect them in the context of the microbiome.

Peritoneal dialysis-associated peritonitis caused by Tsukamurella inchonensis: a case report and literature review

BackgroundPeritoneal dialysis (PD)-associated peritonitis is a serious complication that can lead to PD discontinuation and mortality. Tsukamurella species are uncommon opportunistic pathogens that can cause peritonitis, often necessitating catheter removal.Case presentationA 46-year-old woman with a 1.5-year history of PD presented with fever and lower abdominal pain, along with cloudy peritoneal effluent showing an elevated cell count. Empiric antibiotic therapy with ciprofloxacin, cefazolin, and ceftazidime was started for PD-associated peritonitis. The peritoneal effluent culture yielded a gram-positive rod with weak acid-fast staining. A rebound in the cell count necessitated a switch of antibiotics to meropenem and vancomycin. This led to improvement, and the treatment was switched to oral levofloxacin on day 30 and the patient was discharged on day 35. Subsequently, 16S rRNA gene sequencing confirmed the isolate as Tsukamurella inchonensis.ConclusionThis case highlights the challenges in identifying and treating Tsukamurella peritonitis. Successful treatment without catheter removal in this case suggests that early detection and appropriate antibiotics may enable catheter salvage in this rare infection. However, further research is needed to establish optimal treatment strategies.

Engineered fungus containing a caterpillar gene kills insects rapidly by disrupting their ecto- and endo-microbiomes

Similar to the physiological importance of gut microbiomes, recent works have shown that insect ectomicrobiotas can mediate defensive colonization resistance against fungal parasites that infect via cuticle penetration. Here we show that engineering the entomopathogenic fungus Metarhizium robertsii with a potent antibacterial moricin gene from silkworms substantially enhances the ability of the fungus to kill mosquitos, locusts, and two Drosophila species. Further use of Drosophila melanogaster as an infection model, quantitative microbiome analysis reveals that engineered strains designed to suppress insect cuticular bacteria additionally disrupt gut microbiomes. An overgrowth of harmful bacteria such as the opportunistic pathogens of Providencia species is detected that can accelerate insect death. In support, quantitative analysis of antimicrobial genes in fly fat bodies and guts indicates that topical fungal infections result in the compromise of intestinal immune responses. In addition to providing an innovative strategy for improving the potency of mycoinsecticides, our data solidify the importance of both the ecto- and endo-microbiomes in maintaining insect wellbeing.

Comparative genomic analysis of an emerging Pseudomonadaceae member, Thiopseudomonas alkaliphila.

Thiopseudomonas alkaliphila, an organism recently classified within the Pseudomonadaceae family, has been detected in diverse sources such as human tissues, animal guts, industrial fermenters, and decomposition environments, suggesting a diverse ecological role. However, a large knowledge gap exists in how T. alkaliphila functions. In this comparative genomic analysis, adaptations indicative of habitat specificity among strains and genomic similarity to known opportunistic pathogens are revealed. Genomic investigation reveals a core metabolic utilization of multiple oxidative and non-oxidative catabolic pathways, suggesting adaptability to varied environments and carbon sources. The genomic repertoire of T. alkaliphila includes secondary metabolites, such as antimicrobials and siderophores, indicative of its involvement in microbial competition and resource acquisition. Additionally, the presence of transposases, prophages, plasmids, and Clustered Regularly Interspaced Short Palindromic Repeats-Cas systems in T. alkaliphila genomes suggests mechanisms for horizontal gene transfer and defense against viral predation. This comprehensive genomic analysis expands our understanding on the ecological functions, community interactions, and potential virulence of T. alkaliphila, while emphasizing its adaptability and diverse capabilities across environmental and host-associated ecosystems.IMPORTANCEAs the microbial world continues to be explored, new organisms will emerge with beneficial and/or pathogenetic impact. Thiopseudomonas alkaliphila is a species originally isolated from clinical human tissue and fluid samples but has not been attributed to disease. Since its classification, T. alkaliphila has been found in animal guts, animal waste, decomposing remains, and biogas fermentation reactors. This is the first study to provide an in-depth view of the metabolic potential of publicly available genomes belonging to this species through a comparative genomics and draft pangenome calculation approach. It was found that T. alkaliphila is metabolically versatile and likely adapts to diverse energy sources and environments, which may make it useful for bioremediation and in industrial settings. A range of virulence factors and antibiotic resistances were also detected, suggesting T. alkaliphila may operate as an undescribed opportunistic pathogen.

First detection of Cupriavidus gilardii in a bovine neonatal diarrhea outbreak

BackgroundCupriavidus gilardii is an aerobic, gram-negative, motile, glucose-nonfermenting bacillus, first described in 1999. Typically, it exhibits low pathogenicity in humans, causing opportunistic infections primarily in individuals with compromised immune systems. This bacterium has been also found in various environmental sources such as plants and contaminated soils. Notably, there have been no documented cases of C. gilardii infections in animals.Case presentationThis case report outlines a bovine neonatal diarrhea outbreak that occurred in Northern Greece, during which C. gilardii was isolated. Faecal samples from 5-day-old calves were collected and transported to the laboratory for further examination. Bacterial culture and next generation sequencing techniques were employed to confirm the presence of this bacterium in the samples. Following the isolation and identification of C. gilardii from the samples, an autogenous vaccine was produced and administered to the cows within the farm. Subsequent to vaccination, a progressive reduction in calf diarrhea and deaths was observed, leading to their eventual complete resolution. To the best of our knowledge, this represents the first documentation of C. gilardii isolation from cases of bovine neonatal diarrhea.ConclusionThis case report presents the first isolation case of C. gilardii from animal samples and more specifically from calf faecal samples. It represents an important observation, providing evidence that this opportunistic human pathogen could contribute to clinical symptoms in animals.

Acinetobacter baumannii OmpA-like porins: functional characterization of bacterial physiology, antibiotic-resistance, and virulence

Acinetobacter baumannii is a critical opportunistic pathogen associated with nosocomial infections. The high rates of antibiotic-resistance acquisition make most antibiotics ineffective. Thus, new medical countermeasures are urgently needed. Outer membrane proteins (OMPs) are prime candidates for developing novel drug targets and antibacterial strategies. However, there are substantial gaps in our knowledge of A. baumannii OMPs. This study reports the impact of OmpA-like protein on bacterial physiology and virulence in A. baumannii strain AB5075. We found that PsaB (ABUW_0505) negatively correlates to stress tolerance, while ArfA (ABUW_2730) significantly affects bacterial stiffness, cell shape, and cell envelope thickness. Furthermore, we expand our knowledge on YiaD (ABUW_3045), demonstrating structural and virulence roles of this porin, in addition to meropenem resistance. This study provides solid foundations for understanding how uncharacterized OMPs contribute to A. baumannii's physiological and pathological processes, aiding the development of innovative therapeutic strategies against A. baumannii infections.

Progressive Multifocal Leukoencephalitis of the Immunocompromised Subject: A Case Report from Zinder National Hospital

Progressive multifocal leukoencephalitis (PML) is a rare opportunistic infection of HIV-infected individuals. It is a viral infection caused by the John Cunningham (JC) virus, which occurs during the AIDS stage. An elderly patient immunosuppressed by HIV for more than 5 years presented to the HNZ SMIT with headache, vomiting, visual disturbances, speech disorders and numbness of the limbs, all of which had been evolving in a febrile context for more than seven months. Neurological examination revealed left hemiparesis, frontal syndrome, temporal syndrome and homolateral hemianopia. Cerebral computed tomography revealed multiple lesions of leukoencephalitis. PCR revealed JC virus. The patient was put on corticosteroids, rehydration and nursing care. The course was marked by a progressive deterioration in the patient's neurological condition, culminating in death. We report the clinical, biological and CT features of this progressive multifocal leukoencephalitis.

Altered Mental Status in Cancer.

Patients with cancer experience high rates of alterations in mental status. The mechanisms for altered mental status (AMS) in this population are manifold. The cancer itself may cause AMS through direct invasion of the central nervous system or as metastatic leptomeningeal spread. However, cancer patients are also vulnerable to tumor-associated complications such as seizures, cerebral edema, strokes, or cancer treatment-related complications such as infections, direct neural injury from radiation or chemotherapy, edema, or dysregulated autoimmune response from immunotherapies. Both during treatment and as sequelae, patients may suffer neurocognitive complications from chemotherapy and radiation, medications or opportunistic infections, as well as toxic-metabolic, nutritional, and endocrine complications. In this review, we describe a clinical approach to the cancer patient presenting with AMS and discuss the differential drivers of AMS in this patient population. While common etiologies of AMS in noncancer patients (toxic-metabolic or infectious encephalopathy, delirium) are also applicable to cancer patients, we additionally provide a cancer-specific differential diagnosis that warrants special consideration in the cancer patient with AMS.

Antibiotic resistance and virulence characteristics of Vibrio vulnificus isolated from Ningbo, China

BackgroundVibrio vulnificus (V. vulnificus) is a deadly opportunistic human pathogen with high mortality worldwide. Notably, climate warming is likely to expand its geographical range and increase the infection risk for individuals in coastal regions. However, due to the absence of comprehensive surveillance systems, the emergence and characteristics of clinical V. vulnificus isolates remain poorly understood in China.MethodsIn this study, we investigate antibiotic resistance, virulence including serum resistance, and hemolytic ability, as well as molecular characteristics of 21 V. vulnificus isolates collected from patients in Ningbo, China.Results and discussionThe results indicate that all isolates have been identified as potential virulent vcg C type, with the majority (16 of 21) classified as 16S rRNA B type. Furthermore, these isolates exhibit a high level of antibiotic resistance, with 66.7% resistance to more than three antibiotics and 61.9% possessing a multiple antibiotic resistance (MAR) index exceeding 0.2. In terms of virulence, most isolates were categorized as grade 1 in serum resistance, with one strain, S12, demonstrating intermediate sensitivity in serum resistance, belonging to grade 3. Whole genome analysis disclosed the profiles of antibiotic resistance genes (ARGs) and virulence factors (VFs) in these strains. The strains share substantial VF genes associated with adherence, iron uptake, antiphagocytosis, toxin, and motility. In particular, key VFs such as capsule (CPS), lipopolysaccharide (LPS), and multifunctional autoprocessing repeats-in-toxin (MARTX) are prevalent in all isolates. Specifically, S12 possesses a notably high number of VF genes (672), which potentially explains its higher virulence. Additionally, these strains shared six ARGs, namely, PBP3, adeF, varG, parE, and CRP, which likely determine their antibiotic resistance phenotype.ConclusionOverall, our study provides valuable baseline information for clinical tracking, prevention, control, and treatment of V. vulnificus infections.

Microbiological Landscape of Intensive Care Unit: A Retrospective Analysis of Bacterial Pathogens and Their Implications

Introduction: The intensive care unit (ICU) is a high-risk environment for hospital-acquired infections (HAIs) due to the complex interplay of patient vulnerability, invasive procedures, and the selective pressure of antimicrobial use. Understanding the local epidemiology of bacterial pathogens is crucial for effective infection prevention and control strategies. This study aimed to characterize the bacterial profile in an ICU setting, providing insights into the prevalent pathogens and their potential implications for patient care. Methods: A retrospective cross-sectional study was conducted, encompassing patients admitted to the ICU of Bangli Hospital Bali in 2023 and 2024. Data on patient demographics, sample sources, and microbiological findings were collected from medical records. Samples included blood cultures, sputum cultures (from both endotracheal tubes and spontaneous expectoration), wound swabs, and other sterile site cultures. Microbiological identification was performed using standard laboratory techniques. Results: A total of 219 patients were included in the study. The most common sample source was blood culture (42.9%), followed by sputum culture from endotracheal tubes (39.3%). A significant proportion of cultures showed no growth (34.7%), highlighting the challenges in identifying causative pathogens in the ICU. Among the identified pathogens, Staphylococcus spp. was predominant (15.5%), followed by Stenotrophomonas maltophilia (9.6%) and coagulase-negative staphylococci (8.7%). The distribution of pathogens varied across sample sources, with Staphylococcus spp. being prevalent in sputum cultures from endotracheal tubes and Klebsiella pneumoniae in sputum cultures. Conclusion: This study underscores the dynamic nature of the microbiological landscape in the ICU. The predominance of Staphylococcus spp., Stenotrophomonas maltophilia, and other opportunistic pathogens emphasizes the need for robust infection prevention and control measures. Further research is warranted to explore the impact of these pathogens on patient outcomes and to optimize antimicrobial stewardship in this critical care setting.

Gastrointestinal Bleeding as a Clinical Manifestation of Strongyloides stercoralis Hyperinfection in a Patient with HIV: A Case Report

AbstractStrongyloidiasis, caused by the nematode Strongyloides stercoralis, is an often neglected parasitic disease, with deeper prevalence in tropical and subtropical regions. This parasitic infection can range from asymptomatic to symptomatic, with nonspecific manifestations, including gastrointestinal symptoms. Herein, we reported the case of an human immunodeficiency virus (HIV)-positive patient, under effective antiretroviral treatment with a normal CD4 count, who was hospitalized due to gastrointestinal bleeding. The diagnosis of strongyloidiasis hyperinfection was confirmed following endoscopic biopsies of both the gastric and duodenal mucosa. Subsequently, a treatment regimen of ivermectin at a dosage of 200 mcg/kg/day for a duration of 14 days was initiated, leading to notable amelioration in the patient's clinical presentation. In considering the differential diagnosis of gastrointestinal bleeding, it is crucial to explore various possibilities, including peptic ulcers, portal hypertension, and cancer. Among immunocompromised individuals like those with HIV, chronic infection can compromise the Th2 immune response, which is pivotal in combating helminthic infections. This underscores the importance of remembering intestinal parasitosis, particularly strongyloidiasis, in such cases. Even in patients with preserved CD4 counts, careful evaluation for opportunistic infections in HIV-positive individuals is paramount. Early initiation of treatment is essential to mitigate the risk of serious complications.

Human granulocytotropic anaplasmosis-A systematic review and analysis of the literature.

Human granulocytotropic anaplasmosis (HGA) is a zoonotic tick-borne bacterial infection caused by Anaplasma phagocytophilum. While most cases are reported from North America, HGA has been recognized as an emerging disease in several regions of the world in recent decades. Most available data comes from case reports, case series and retrospective studies, while prospective studies and clinical trials are largely lacking. To obtain a clearer picture of the currently known epidemiologic distribution, clinical and paraclinical presentation, diagnostic aspects, complications, therapeutic aspects, and outcomes of HGA, we systematically reviewed the literature and analyzed and summarized the data. Cases of HGA are reported from all continents except from Antarctica. HGA primarily presents as an unspecific febrile illness (88.5% of the cases) often accompanied by thrombocytopenia (71.8% of the cases), abnormal liver injury tests (66.7% of the cases), and leukopenia (49.8% of the cases). Although we found complications reported in a total of 40.5% of the reviewed cases and severe and even life-threatening complications are not infrequent (e.g. acute renal failure 9.8%, multi organ failure 7.5%, ARDS 6.3%, a.o.), sequelae are rare (2.1% of the cases) and lethality is low (3.0% of the cases). Treatment with doxycycline shows a rapid response, with the fever subsiding in the majority of patients within one day of starting treatment. Unlike in human monocytotropic ehrlichiosis (HME), reports of opportunistic infections complicating HGA are rare. HGA during pregnancy does not appear to be associated with unfavorable outcomes. In addition, our analysis provides some evidence that HGA may differ in clinical aspects and laboratory characteristics in different regions of the world. Overall, the data analyzed indicates a non-negligible bias in reporting/publication, so a certain degree of caution is required when generalizing the data.

Carbon Dots as Bioactive Antifungal Nanomaterials.

Nowadays, the widespread diffusion of infections caused by opportunistic fungi represents a demanding threat for global health security. This phenomenon has also worsened by the emergence of contagious events in hospitalisation environments and by the fact that many fungi have developed harsh and serious resistance mechanisms to the traditional antimycotic drugs. Hence, the design of novel antifungal agents is a key factor to counteract mycotic infections and resistance. Within this context, nanomaterials are gaining increasing attention thanks to their biocidal character. Among these, carbon dots (CDs) represent a class of zero-dimensional, photoluminescent and quasi-spherical nanoparticles which, for their great and tuneable features, have found applications in catalysis, sensing and biomedicine. Nevertheless, only a few works define and recapitulate their antifungal properties. Therefore, we aim to give an overview about the recent advances in the synthesis of CDs active against infective fungi. We described the general features of CDs and fungal cells, by highlighting some of the most common antimycotic mechanisms. Then, we evaluated the effects of CDs, antimicrobial drugs-loaded CDs and CDs-incorporated packaging systems on different fungi and analysed the use of CDs as fluorescent nano-trackers for bioimaging, showing, to all effects, their promising application as antifungal agents.

Phytochemical Composition and Antimicrobial and Antibiofilm Effect of Myrciaria cauliflora Hydroethanolic Extract against Staphylococcus aureus and Acinetobacter baumannii

Staphylococcus aureus and Acinetobacter baumannii are opportunistic pathogens, and both are involved in different oral infections. This work aimed to analyze the phytochemical composition of Myrciaria cauliflora hydroethanolic extract and to evaluate its antimicrobial and antibiofilm action against Staphylococcus aureus (ATCC 6538) and Acinetobacter baumannii (ATCC 19606; multi-resistant clinical strains 58004, 50098, 566006, and H557). Myrciaria cauliflora hydroethanolic extract was prepared, and the content of soluble solids, flavonoids, and phenols was quantified. High-performance liquid chromatography (HPLC) was performed later. The minimum inhibitory concentration was determined using the broth microdilution method according to the Clinical and Laboratory Standards Institute, standard M7-A6, and subsequently, its minimum bactericidal concentration was determined. Then, the most effective concentrations were analyzed against biofilms. Statistical analysis was performed using the ANOVA method with Tukey’s test. The soluble solids content in the prepared hydroethanolic extract of M. cauliflora was 2.22%. Additionally, the total flavonoid content, measured using the quercetin standard curve, was 0.040 mg/mL. Furthermore, the total phenol content, determined using the gallic acid standard curve, was 0.729 mg/mL. HPLC analysis presented peaks of gallic acid (11.80 m), p-coumaric acid (12.09 m), cinnamic acid derivative (19.02 m), and ellagic acid (29.83 m). The extract demonstrated antimicrobial and antibiofilm action against all tested strains. However, the most effective antibacterial concentration against all the tested bacteria was 5.55 mg/mL. Therefore, these chemical components justify that M. cauliflora hydroethanolic extract is effective in reducing biofilm formation in S. aureus (standard strain) and A. baumannii (standard and clinical strains).

Photogallery. Human papillomavirus infection of the skin and mucous membranes in people living with HIV

The human papillomavirus is ubiquitous. It is estimated that over a third of people with apparently healthy skin are carriers of human papillomavirus. HIV-associated immunodeficiency contributes to the manifestation of clinical symptoms of human papillomavirus infection. Against the background of severe (the number of CD4+ T-lymphocytes below 200 cells/μl) and pronounced (CD4+ T-lymphocytes from 200 to 349 cells/μl) immunodeficiency caused by HIV infection (human immunodeficiency virus), the period of persistence of human papillomavirus is longer, and the clinical picture and course of human papillomavirus infection can significantly differ compared to HIV-positive individuals with intact immunity and people without HIV. At the same time, formations on the skin and mucous membranes are often multiple and can be characterized by rapid growth, large size, location outside the typical localization, resistance to treatment, recurrent course, and lack of tendency to spontaneous regression. Taking antiretroviral drugs for the treatment of HIV infection has a generally beneficial effect on the clinical course and prognosis of viral warts; With regard to anogenital warts, the researchers’ conclusions are not so clear. A number of experts believe that viral-immunological control of HIV infection may not be sufficient to successfully combat venereal warts. The photogallery presents various clinical types of viral and anogenital (venereal) warts in people living with HIV. Each of them is assigned one of the variants of the stage of secondary diseases of HIV infection (4A, 4B or 4V according to its Russian clinical classification) depending on the severity of concomitant opportunistic diseases. In all clinical cases, with the exception of the last one, patients experienced severe or pronounced immunodeficiency and progression of HIV infection in the absence of antiretroviral therapy. In the last observation, giant Buschke–Levenstein condyloma developed with a slight immunodeficiency against the background of effective antiretroviral therapy.

A novel PCR-based genotyping method for Proteus mirabilis – Intergenic region polymorphism analysis

Proteus mirabilis is a predominant species in cases of food poisoning associated with meat products and is also an opportunistic pathogen causing numerous infections in humans. This study aimed to differentiate P. mirabilis isolates using intergenic region polymorphism analysis (IRPA). The IRPA typing scheme was developed to amplify polymorphic fragments in intergenic regions (IGRs). The presence, absence, or size change of amplified products were identified and utilized as genetic markers for rapid differentiation of strains. A total of 75 P. mirabilis isolates were isolated from 63 fresh poultry and pork samples were subtyped using the IRPA and ERIC-PCR methods, and their antibiotic resistance profiles were tested. The majority of P. mirabilis isolates showed resistance to tetracycline (85.3%), doxycycline (93.3%), chloramphenicol (82.7%), streptomycin (92.0%), spectinomycin (80.0%), trimethoprim (97.3%); trimethoprim-sulfalleth (82.7%), and erythromycin (100.0%). In contrast, resistance rates to ceftriaxon, cefoxitin, cefepime, and cefotaxim were lower at only 17.3%, 5.3%, 6.7%, and 13.3%, respectively, among P. mirabilis isolates. Eleven loci were selected for analysis of the genetic diversity of 75 P. mirabilis isolates. A combination of 4 loci was determined as the optimal combination. The results compared to those obtained using ERIC-PCR for the same isolates. The Simpson's index of diversity was 0.999 for IRPA and 0.923 for ERIC-PCR, indicating that IRPA has a higher discriminatory power than ERIC-PCR. The concordance between IRPA and ERIC-PCR methods was low, primarily because IRPA classified isolates from the same ERIC cluster into separate clusters due to its high resolution. The IRPA method presented in this study offers a rapid, simple, reproducible, and economical approach for genotyping P. mirabilis.

Human monocytotropic ehrlichiosis-A systematic review and analysis of the literature.

Human monocytotropic ehrlichiosis (HME) is a tick-borne bacterial infection caused by Ehrlichia chaffeensis. Most available data come from case reports, case series and retrospective studies, while prospective studies and clinical trials are largely lacking. To obtain a clearer picture of the currently known epidemiologic distribution, clinical and paraclinical presentation, diagnostic aspects, complications, therapeutic aspects, and outcomes of HME, we systematically reviewed the literature and analyzed and summarized the data. Cases of HME are almost exclusively reported from North America. Human infections due to other (non-chaffeensis) Ehrlichia spp. are rare. HME primarily presents as an unspecific febrile illness (95% of the cases), often accompanied by thrombocytopenia (79.1% of the cases), leukopenia (57.8% of the cases), and abnormal liver function tests (68.1% of the cases). Immunocompromized patients are overrepresented among reviewed HME cases (26.7%), which indicates the role of HME as an opportunistic infection. The incidence of complications is higher in immunocompromized compared to immunocompetent cases, with ARDS (34% vs 19.8%), acute renal failure (34% vs 15.8%), multi organ failure (26% vs 14.9%), and secondary hemophagocytic lymphohistiocytosis (26% vs 14.9%) being the most frequent reported. The overall case fatality is 11.6%, with a significant difference between immunocompetent (9.9%) and immunocompromized (16.3%) cases, and sequelae are rare (4.2% in immunocompetent cases, 2.5% in immunocompromised cases).

Nosema bombycis: A remarkable unicellular parasite infecting insects.

Microsporidia are opportunistic fungal-like pathogens that cause microsporidiosis, which results in significant economic losses and threatens public health. Infection of domesticated silkworms by the microsporidium Nosema bombycis causes pébrine disease, for which this species of microsporidia has received much attention. Research has been conducted extensively on this microsporidium over the past few decades to better understand its infection, transmission, host-parasite interaction, and detection. Several tools exist to study this species including the complete genome sequence of N. bombycis. In addition to the understanding of N. bombycis being important for the silkworm industry, this species has become a model organism for studying microsporidia. Research on biology of N. bombycis will contribute to the development of knowledge regarding microsporidia and potential antimicrosporidia drugs. Furthermore, this will provide insight into the molecular evolution and functioning of other fungal pathogens.