Disease Pathogen Research Articles

Antimicrobial Activities of Citrus Seed and Leaf Extracts Against Selected Bacterial and Fungal Pathogens Linked to Human Diseases: In vitro Experimental Study in Musanze, Rwanda

Antimicrobial resistance has caused major challenges in both bacterial and fungal infections. Therefore, the current study was designed to evaluate the antimicrobial activity with different crude extracts of leaves and seeds of Citrus limon against Gram-positive (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa) and fungi (Cryptococcus neoformans and Candida albicans) obtained from different clinical settings. Filtrate extracts after maceration technique and the phytochemical substances detected in plants were flavonoid, saponin, alkaloid, glycoside, and resin under investigation. In vitro, a disc diffusion assay was applied to measure the inhibition zone of the plant effect in millimeters (mm). It was observed that Citrus limon activity showed the highest on ethanolic seed against Staphylococcus aureus and the lowest activity plant observed on methanolic leaf extract against Klebsiella oxytoca. The mean values of Citrus limon extract convinced there was no statistically significant correlation among extract solvents used in the study (ρ > 0.05). Oxacillin was used as the positive control and discs without antibiotic content as the negative control during testing. To conclude, ethanolic seed extract has shown the highest effect against Staphylococcus aureus and Salmonella typhi from isolate. Indeed, plant extracts that showed potential effectiveness, such as (Citrus leaves and seeds) can be used as natural alternative preventive measures to control pathogenic bacterial diseases and prevent the rise of antibiotic resistance. Furthermore, studies to evaluate the in vivo potential in an animal model are recommended. Keywords: Citrus limon, Crude extract, Bacteria, Fungi, Antimicrobial resistance.

Multidrug-Resistant Corynebacterium spp., Escherichia coli, and Klebsiella spp. Isolated from the Lungs of a Six-Year-Old Arewa Stallion

This manuscript presents a case of multidrug-resistant (MDR) bacterial infections in the respiratory system of a6-year-old Arewa stallion, thus highlighting the importance of diagnostic microbiology. History revealed that the stallion exhibited clinical signs, including high fever, hemoglobinuria, and edema of the head and neck, and this was followed by death despite medical intervention. Postmortem was pneumonia; hence lung sample was sent for microbiological analyses. The diagnostic microbiological techniques utilized were culture on blood MacConkey and Eosin Methylene Blue agars, and biochemical tests were used to confirm the bacterial identities, followed by antibiotic susceptibility testing. The outcomes revealed the isolation of Corynebacterium spp., Escherichia coli, and Klebsiella spp. Antibiotic susceptibility testing revealed extensive resistance, with Corynebacterium spp. resistant to Septrin, Chloramphenicol, Sparfloxacin, Ciprofloxacin, and more. E. coli and Klebsiella spp. were resistant to Ciprofloxacin, Gentamicin, Nitrofurantoin, Ofloxacin, Cefuroxime, Ceftazidime, Augmentin, and Cotrimoxazole. These findings emphasize the diagnostic challenges caused by MDR pathogens in equine respiratory diseases.

Discovery of Peptidic Siderophore Degradation by Screening Natural Product Profiles in Marine-Derived Bacterial Mono- and Cocultures.

Coral reefs are hotspots of marine biodiversity, which results in the synthesis of a wide variety of compounds with unique molecular scaffolds, and bioactivities, rendering reefs an ecosystem of interest. The chemodiversity stems from the intricate relationships between inhabitants of the reef, as the chemistry produced partakes in intra- and interspecies communication, settlement, nutrient acquisition, and defense. However, the coral reefs are declining at an unprecedented rate due to climate change, pollution, and increased incidence of pathogenic diseases. Among pathogens, Vibrio spp. bacteria are key players resulting in high mortality. Thus, alternative strategies such as application of beneficial bacteria isolated from disease-resilient species are being explored to lower the burden of pathogenic species. Here, we apply coculturing of a coral-derived pathogenic species of Vibrio and beneficial bacteria and leverage recent advancements in untargeted metabolomics to discover engineerable beneficial traits. By chasing chemical change in coculture, we report Microbulbifer spp.-mediated degradation of amphibactins, produced by Vibrio spp. bacteria to sequester iron. Additional biochemical experiments revealed that the degradation occurs in the peptide backbone and requires the enzyme fraction of Microbulbifer. A reduction in iron affinity is expected due to the loss of one Fe(III) binding moiety. Therefore, we hypothesize that this degradation shapes community behaviors as it pertains to iron acquisition, a limiting nutrient in the marine environment, and survival. Furthermore, Vibrio sp. bacteria suppressed natural product synthesis by beneficial bacteria. Understanding biochemical mechanisms behind these interactions will enable engineering probiotic bacteria capable of lowering pathogenic burdens during heat waves and incidence of disease.

Functional Characterization and In Silico Prediction Tools Improve the Pathogenicity Prediction of Novel Bile Acid Transporter Variants.

The pathogenicity of cholestatic liver diseases (CLDs) remains insufficiently characterized, hindering definitive diagnosis and timely treatment. The aim of this study was to improve the pathogenicity prediction of novel bile acid (BA) transporter variants in patients with CLDs. We analyzed the clinical characteristics and genetic profiles of a CLD cohort (n = 57) using multiple in silico tools and invitro functional assays. We identified 78 unique variants in four BA transporter genes. The predominant defects were associated with ABCC2 (57/78, 73.1%), with the most frequent being missense variants (39/78, 50.0%). Using in silico tools, we identified 47 novel variants: 12 mis-splicing, 21 deleterious missense, and 23 with altered protein stability. Of the 34 novel variants in ABCC2 identified through invitro functional assays, seven incurred aberrant splicing, 11 missense variants resulted in MRP2 reduction, 9 missense variants resulted in abnormal N-glycosylation, 18 variants altered MRP2 localization, and 26 variants reduced organic anion transport activity. These findings indicate that a multidisciplinary approach, integrating bioinformatics and experimental data, significantly enhances the accuracy of genetic-based CLD diagnosis. It serves as a foundational study for BA transport variants pathogenicity reclassification and expands the mutation spectrum of CLDs in China.

Elevated CO2 alters soybean physiology and defense responses, and has disparate effects on susceptibility to diverse microbial pathogens.

Increasing atmospheric CO2 levels have a variety of effects that can influence plant responses to microbial pathogens. However, these responses are varied, and it is challenging to predict how elevated CO2 (eCO2) will affect a particular plant-pathogen interaction. We investigated how eCO2 may influence disease development and responses to diverse pathogens in the major oilseed crop, soybean. Soybean plants grown in ambient CO2 (aCO2, 419 parts per million (ppm)) or in eCO2 (550 ppm) were challenged with bacterial, viral, fungal, and oomycete pathogens. Disease severity, pathogen growth, gene expression, and molecular plant defense responses were quantified. In eCO2, plants were less susceptible to Pseudomonas syringae pv. glycinea (Psg) but more susceptible to bean pod mottle virus, soybean mosaic virus, and Fusarium virguliforme. Susceptibility to Pythium sylvaticum was unchanged, although a greater loss in biomass occurred in eCO2. Reduced susceptibility to Psg was associated with enhanced defense responses. Increased susceptibility to the viruses was associated with reduced expression of antiviral defenses. This work provides a foundation for understanding how future eCO2 levels may impact molecular responses to pathogen challenges in soybean and demonstrates that microbes infecting both shoots and roots are of potential concern in future climatic conditions.

Gene Editing and Protein Tagging in the Oomycete Phytophthora infestans Using CRISPR-Cas12a.

Molecular genetic tools such as CRISPR-Cas gene editing systems are invaluable for understanding gene and protein function and revealing the details of a pathogen's life and disease cycles. Here we present protocols for genome editing in Phytophthora infestans, an oomycete with global importance as a pathogen of potato and tomato. Using a vector system that expresses variants of Cas12a from Lachnospiraceae bacterium and its guide RNA from a unified transcript, we first present a method for editing genes through the non-homologous end-joining (NHEJ) pathway. We then describe an application of homology-directed repair (HDR), in which Cas12a is used to fuse a protein-coding gene with a fluorescent or epitope tag. Both methods should be adaptable to many oomycetes other than P. infestans.

Bacillus pumilus SMU5927 protect mice from damage caused by Salmonella Enteritidis colonization

BackgroundSalmonella Enteritidis is one of the main pathogens of foodborne diseases and an important pathogen causing diarrhea in yaks. Antibiotics are the mainstay of treatment for salmonellosis, but the widespread use of antibiotics has increased Salmonella resistance. Probiotics have been shown to antagonize Salmonella and reduce Salmonella infection. Bacillus pumilus is one of the microbial feed additives approved by the Chinese Ministry of Agriculture for use in animal breeding, which has the effect of improving animal growth performance and immunity, among others. Therefore, this paper explored the anti-infective effect of Bacillus pumilus against Salmonella. ResultsBacillus pumilus SMU5927 significantly enhances the intestinal mechanical barrier and reduces the number of Salmonella transferred to the organs. Bacillus pumilus SMU5927 ameliorated intestinal tissue damage and attenuated intestinal inflammatory responses in mice. In addition, Bacillus pumilus increased the ratio of the Firmicutes/Bacteroidetes in the intestinal flora, increased the abundance of beneficial bacteria such as Lactobacillus, and decreased the abundance of harmful bacteria. ConclusionThis study confirmed the role of Bacillus pumilus SMU5927 in preventing and attenuating Salmonella damage and provided ideas for the development of novel antimicrobial drugs.

History of Health at Cayo Santiago-An Investigation of Environmental and Genetic Influences on the Skeletal Remains of the Introduced Rhesus Macaque (Macaca mulatta) Colony.

The Cayo Santiago rhesus macaque colony is a renowned primate population that has experienced significant natural and anthropogenic ecological variation in their 85-year history. Demographic and familial information is also tracked and collated for the majority of monkeys. Thus, the health history of rhesus macaques at Cayo Santiago should reflect the impacts of both environmental and genetic factors. In this study, we utilized a sample of skeletal remains comprised of 2787 individuals (1571 females, 1091 males), born between 1938 and 2017 from the derived skeletal collection of the primate colony to assess variation in survivorship, pathology, bone mineral density (BMD), and dental eruption status, in the context of hurricane impacts, nutritional fluctuations, and matriline genealogy. Results demonstrated that rhesus macaques at Cayo Santiago exhibit a range of skeletal pathologies that encompass biomedical and archaeological significance, multiple etiologies, severities, locations, and types, in addition to a secular trend of declining BMD that is hypothesized to reflect decreasing physical activity levels under increasing population densities. Specifically, hurricane impacts were found to increase the rate of systemic disease, decrease BMD in young adults, and delay eruption of the primary dentition. Certain matrilines exhibited heightened levels of systemic disease at early ages while others exhibited greater rates of congenital disease. Early-life adversity, through the experience of major hurricanes, may enhance inflammatory pathways, heightening the risk of disease and accelerating the aging process leading to reduced BMD. Such impacts may underly greater levels of observed infection post-hurricane through intensification of pathogen transmission and disease rates brought on by hurricane-adaptive social strategies that favor closer proximity. Familial susceptibility to disease indicates heritable host genetic factors are likely influencing disease patterning in the population. A cluster of congenital diseases may most convincingly illustrate this, or alternatively reflects low levels of genetic diversity in the population.

The characterization and antifungal activities of two new Trichoderma antagonistic fungi against four apple disease pathogens

The characterization and antifungal activities of two new Trichoderma antagonistic fungi against four apple disease pathogens

Recent developments in isothermal amplification technology for rapid detection of SARS-CoV-2.

Coronavirus disease 2019 (COVID-19), an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread globally, posing a significant threat to human health. Rapid and accurate detection of infectious disease pathogens is of crucial practical significance for early screening, timely intervention, and outbreak prevention. However, conventional diagnostic methods are increasingly unable to meet clinical demands. Recently developed isothermal analysis methods offer mild reaction conditions and reduce dependence on specialized instruments. These convenient, fast, and reliable methods show great promise for diagnosing infectious pathogens, especially for on-site detection in areas without laboratories or with limited resources. Among them, loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), which integrate various widely used detection techniques, stand out as rapidly advancing and relatively mature isothermal nucleic acid amplification technologies. This review outlines several representative isothermal amplification technologies and associated detection methods. We summarize the latest advancements in LAMP and RPA technologies for the rapid detection of SARS-CoV-2 and discuss the future prospects of isothermal amplification in diversified testing.

In Vitro Efficacy of Some Medicinal Plant-Extracts Against Curvularia lunata Causing Blight Disease of Solanum nigrum L.

Fungi are both harmful and beneficial to plants they are the causative agents of many plant diseases through the use of diverse strategies. Sometimes they kill their host plants thus there is a need to control the fungi for proper growth and development of plants. Curvularia lunata (Wakker) Boedijn is a causative pathogen of many medicinal plant diseases, especially leaf spot and blight disease of Solanum nigrum L. The present study was conducted to determine the inhibitory effects of six selected medicinal plant extracts viz. Ocimum sanctum L., Solanum melongena L., Bergera koenigii L., Calotropis gigantean (L.) W.T.Aiton, Justicia adhatoda L., Andrographis paniculata (Burm.f.) Wall. ex Nees against mycelial growth of Curvularia lunata. Both ethanolic extract and aqueous extract show significant inhibition of tested pathogenic fungi as compared to control.

Biofilm as a supracellular organization of pathogenic bacteria

The high frequency of resistance to antibiotics among bacterial clinical isolates necessitates the discovery of new targets for suppressing the pathogenicity of microbes without stimulating their resistance. The studied sources suggest that this can be achieved by targeting the determinants of virulence. The search for new active substances with anti-biofilm activity based on the analysis of literature data on the structure of bacterial biofilms, mechanisms of their resistance to antimicrobial agents was the purpose of this work. An electronic search was conducted in Medline (PubMed interface), Scopus, and Web of Science between 2011 and July, 2024 using the keywords: biofilms, antibiotic resistance, Quorum sensing, persisters. 30 sources were selected, 85 were processed. The subject of the search was: microbial landscape of hospital strains of microorganisms, biofilm formation by microorganisms – pathogens of infectious diseases, regulation of virulence factors in bacterial biofilm. Studies of recent years have established that many pathogenic bacteria produce signal molecules for cellular communication. This signaling system is called Quorum sensing (QS) and it depends on the density of the bacterial population and is mediated by signaling molecules called pheromones or autoinducers (AI). Bacteria use QS to regulate activities and behavior including competence, conjugation, symbiosis, virulence, motility, sporulation, antibiotic production and biofilm formation. Researches aimed at bacterial communicative signals and suppressing QS demonstrate a fundamental approach to forming competitive microbial communication. The search, synthesis, and development of drugs based on modified autoinducers of various natures can lead to a breakthrough in the field of antibacterial therapy of infectious diseases, as well as surgical purulent postoperative complications. The pro­cessed literature describes a number of hypotheses regarding the participation of "toxin-antitoxin" systems that control the growth and metabolism of bacteria in the stimulation of the formation of persister cells. The simultaneous acquisition of resistance to many antibacterial factors, including physico-chemical ones, is suggested. Therefore, there is an increased attention of scientists to the study of the anti-biofilm effect of new compounds and drugs capable of influencing energy or metabolic processes in cells, as well as substances that do not require a metabolically active target. The review illustrates general modern approaches to the use of QS chains in pathogenic bacteria as new therapeutic targets.

Developing Safe Probiotic Solutions for the Treatment of Human Intestinal Infections

In recent years, preparations based on lactic acid bacteria have proven to be effective in the complex therapy of infectious diseases. Despite the large number of positive results of the use of these preparations and their widespread use, there are some risks associated with their use. To minimize these risks, it is necessary to regulate the production, sale, and use of probiotic preparations on an equal basis with medicines. To date, there are no made-in-Kazakhstan probiotic preparations with clinically proven safety and performance in the pharmaceutical market of Kazakhstan. The purpose of this paper was to present preclinical trials of this preparation confirming its safety and medical performance and demonstrate the readiness for clinical trials of the Kazakh probiotic medication AS-Probionorm. The AS-Probionorm probiotic medication developed by us based on an association of specific action lactic acid bacteria (Lactobacillus fermentum 30 and Lactobacillus cellobiosus 36), has high antimicrobial activity against pathogens of intestinal diseases. This study introduces AS-Probionorm as the first locally produced probiotic in Kazakhstan with clinically established safety and effectiveness, marking a significant step forward in the national production of biomedical health solutions.

Phage-mediated virulence loss and antimicrobial susceptibility in carbapenem-resistant Klebsiella pneumoniae.

Bacteriophages, known for their ability to kill bacteria, are hampered in their effectiveness because bacteria are able to rapidly develop resistance, thereby posing a significant challenge for the efficacy of phage therapy. The impact of evolutionary trajectories on the long-term success of phage therapy remains largely unclear. Herein, we conducted evolutionary experiments, genomic analysis, and CRISPR-mediated gene editing, to illustrate the evolutionary trajectory occurring between phages and their hosts. Our results illustrate the ongoing "arms race" between a lytic phage and its host, a carbapenem-resistant Klebsiella pneumoniae clinical strain Kp2092, suggesting their respective evolutionary adaptations that shape the efficacy of phage therapy. Specifically, Kp2092 rapidly developed resistance to phages through mutations in a key phage receptor (galU) and bacterial membrane defenses such as LPS synthesis, however, this evolution coincides with unexpected benefits. Evolved bacterial clones not only exhibited increased sensitivity to clinically important antibiotics but also displayed a loss of virulence in an in-vivo model. In contrast, phages evolved under the selection pressure against Kp2092 mutants and exhibited enhanced bacterial killing potency, targeting mutations in phage tail proteins gp12 and gp17. These parallel evolutionary trajectories suggest a common genetic mechanism driving adaptation, ultimately favoring the efficacy of phage therapy. Overall, our findings highlight the potential of phages not only as agents for combating bacterial resistance, but also a driver of evolution outcomes that could lead to more favorable clinical outcomes in the treatment of multidrug resistance pathogens.IMPORTANCECarbapenem-resistant Klebsiella pneumoniae represents one of the leading pathogens for infectious diseases. With traditional antibiotics often being ineffective, phage therapy has emerged as a promising alternative. However, phage predation imposes a strong evolutionary pressure on the rapid evolution of bacteria, challenging treatment efficacy. Our findings illustrate how co-evolution enhances phage lytic capabilities through accumulated mutations in the tail proteins gp12 and gp17, while simultaneously reducing bacterial virulence and antibiotic resistance. These insights advance our understanding of phage-host interactions in clinical settings, potentially inspiring new approaches akin to an "arms race" model to combat multidrug-resistant crises effectively.

Silver nanoparticles green synthesized using leaf extract of Piper spp. reduce Phytophthora capsici infection in black pepper (Piper nigrum L.)

Black pepper (Piper nigrum L.) is vulnerable to the devastating disease foot rot caused by the oomycete, Phytophthora capsici. Green synthesis of nanoparticles using plant extracts provides an eco-friendly, and economical method for plant disease management. Leaf extracts from two genotypes of pepper plants - one susceptible to foot rot disease (P. capsici) - Piper nigrum, and the other, resistant - Piper colubrinum, were used for synthesizing silver nanoparticles (AgNPs). These green synthesized AgNPs were characterized and evaluated for their anti-oomycete effects against P. capsici and ability to suppress foot rot disease in black pepper. UV Spectroscopic analysis confirmed typical absorption characteristics of AgNPs, while field emission scanning electron microscopy revealed sizes ranging from 39 to 69 nm for both samples. In vitro poisoned food assay demonstrated that the green synthesized AgNPs at 500 and 750 ppm showed highest inhibition on the mycelial growth of the pathogen. Among the treatments,71% and 77% inhibition in mycelial growth of pathogen was observed with 500 ppm and 750 ppm of Pn-AgNPs respectively, and 65% and 73% inhibition in growth of mycelia of pathogen with 500 ppm and 750 ppm of Pc-AgNPs respectively. Copper Oxychloride at 0.2% completely inhibited mycelial growth. In a detached leaf assay with black pepper variety Panniyur-1, significant reduction in lesion development was observed on leaves treated with the green synthesized AgNPs compared to those treated with commercial AgNPs and chitosan nanoparticles. No lesion developed on leaves treated with 750 ppm concentration of green synthesized AgNPs. Leaf extracts were ineffective in disease suppression and pathogen growth. Mild symptoms were observed on leaves treated with the biocontrol agent (Pseudomonas fluorescens, 2%), while no symptoms were found on leaves treated with the fungicide. Spraying of AgNPs green synthesized using leaf extracts of pepper genotypes reduced foot rot disease incidence in susceptible pepper genotype P. nigrum, efficiently. Green nanotechnology for foot rot management can benefit farmers by providing an eco-friendly, cost-effective solution that reduces dependency on chemical fungicides and minimizes environmental impact.

Structural insights into the novel Parkinson’s-linked R1501W mutation in the Roc domain of leucine-rich repeat kinase 2

ABSTRACT Missense mutations in the Leucine-rich repeat kinase 2 (LRRK2) protein are strongly linked to the pathogenicity of both sporadic and familial Parkinson's Disease (PD). Considering their prevalence and functional consequence, mutations causing kinase dysfunction have experienced the greatest exploration. However, variants of LRRK2 with unaltered kinase activity have also been found to cause PD. This study focuses on one such case: the novel R1501W mutation in the Roc-COR (GTPase) domain of LRRK2. Given its novelty, there are scarcely any studies inspecting this variant. Thus, we employed molecular dynamics simulations of 200 ns alongside structural analyses such as root-mean-square (RMS) fluctuation, RMS deviation, radius of gyration, solvent-accessible surface-area, principal component analysis, and free energy landscape to characterise the structural changes occurring in the R1501W mutant in comparison to the wild-type. Our results reveal the introduction of a closed hydrophobic nest in the mutated region, as well as an increase in flexibility, instability, and compactness of the tertiary structure. We speculate that these alterations contribute to a kinase-independent mechanism for pathogenesis. Overall, our investigation showcases the structural dynamics of R1501W mutant LRRK2, providing a backbone for the design of future studies to further inspect the pathogenic pathway employed by this novel variant.

Design, validation, and implementation of multiplex digital PCR assays for simultaneous quantification of multiple targets.

Quantitative polymerase chain reaction (qPCR) and digital PCR (dPCR) are applied for quantifying molecular targets in disease diagnostics, pathogen detection, and ecological monitoring. Uptake of dPCR is increasing due to its higher quantification accuracy relative to qPCR, which stems from its independence from standard curves and its increased resistance to PCR inhibitors. Throughput can be increased through multiplexing, which allows simultaneous quantification of multiple targets. However, multiplexing with dPCR faces unique challenges relative to qPCR. Here, we describe the three-phase development process of non-competing multiplex dPCR assays using target-specific fluorescently labeled hydrolysis probes. We highlight common challenges encountered, along with recommended solutions. Phase 1: In silico assay design; target-specific primers and probes are selected or designed, potential issues with primer and probe interactions are identified, and fluorophores and quenchers are chosen based on dPCR instrumentation. Phase 2: Wet-lab validation; assays are benchmarked using positive controls. Insufficient performance leads to assay redesign, as needed. Phase 3: Assay implementation; assay specificity and sensitivity are validated on relevant sample matrices. Finally, we provide recommendations on the future design and standardization of multiplexed dPCR assays, highlighting the need for better in silico predictions of assay performance, standardizing positive controls, and automating partition classification systems.

Catalogue of inherited autosomal recessive disorders found amongst the Roma population of Europe.

The Roma population are an endogamous, genetically isolated, minority population who migrated from North-Western India to Europe from the 10th Century throughout the Byzantine period and continues to the present day. Approximately 10-12 million Romani people reside in segregated settlements in Europe, and smaller populations live in North America and China. In addition to the endogamy, they also practice consanguinity. This has resulted in a higher frequency of rare autosomal recessive disorders some of which are unique to the Roma population. Some disorders result from founder variants whilst others are private variants, occurring within one nuclear family. Most are found as homozygous variants but compound heterozygosity is seen in a number of conditions. Clinicians and scientists with experience in managing and diagnosing rare diseases in this population in Ireland, Romania and Greece have developed a comprehensive catalogue of autosomal recessive inherited disorders found in the Roma population. Our aim is that this catalogue will aid rapid diagnosis and highlight the differential diagnoses to consider in challenging cases. We performed a detailed literature search to identify relevant publications and disease variants described in patients whose ethnicity was described as Roma. In addition, we interrogated data from local clinicians and colleagues in Ireland and Romania to collect additional unpublished variants which have yet to be reported in the medical literature. Where possible, we have mapped these disorders back to their European country of origin. Furthermore, we searched the variants allele frequencies on ClinVar. We analysed exome data from New Delhi, India to trace any of these founder variants back their origins. We identified 90 distinct autosomal recessive disorders, manifesting as 91 distinct phenotypes and 111 pathogenic disease variants. These include both published (n=91) and unpublished (n=20) findings identified in the Roma population in Europe. The Indian exome data revealed that only 12/111 variants were identified. We have assembled a catalogue of inherited autosomal recessive disorders and 111 pathogenic variants found in the Roma population. We hope that this will assist the medical and scientific community to make prompt diagnoses and consider adaptation of a targeted genetic approach to facilitate timely and cost-effective diagnoses in this population.

Bb0689 contributes to the virulence of Borrelia burgdorferi in a murine model of Lyme disease.

Borrelia burgdorferi, the Lyme disease pathogen, continuously changes its gene expression profile in order to adapt to ticks and mammalian hosts. The alternative sigma factor RpoS plays a central role in borrelial host adaptation. Global transcriptome analyses suggested that more than 100 genes might be regulated by RpoS, but the main part of the regulon remains unexplored. Here, we showed that the expression of bb0689, a gene encoding an outer surface lipoprotein with unknown function, was activated by RpoS. By analyzing gene expression using luciferase reporter assays and quantitative reverse transcription PCR, we found that expression of bb0689 was induced by an elevated temperature, a reduced pH, and increased cell density during in vitro cultivation. The transcriptional start site and a functional promoter for gene expression were identified in the 5' regulatory region of bb0689. The promoter was responsive to environmental stimuli and influenced by RpoS. We also showed that bb0689 expression was expressed in B. burgdorferi during animal infection, suggesting the importance of this gene for infection. We further generated a bb0689 mutant and found that the infectivity of the mutant was severely attenuated in a murine infection model. Although bb0689-deficient spirochetes exhibited no defect during in vitro growth, they were defective in resistance to osmotic stress. Cis-complementation of the mutant with a wild-type copy of bb0689 fully rescued all phenotypes. Collectively, these results demonstrate that the RpoS-regulated gene bb0689 is a key contributor to the optimal infection of B. burgdorferi in animals.

Nasal carriage of multi-drug resistance Staphylococcus aureus constitutes potential zoonosis from poultry farmers and butchers in slaughterhouses in Abakaliki, Ebonyi state, Nigeria

BackgroundIn Nigeria, poultry farming contributes significantly to the economy. Antibiotic use in poultry farming may promote the emergence of multidrug-resistant Staphylococcus aureus, a pathogen of human diseases that inhabit body cavities like the nostrils. This study assessed multi-drug-resistant Staphylococcus aureus in nasal carriage among poultry farmers and butchers in Abakaliki, Ebonyi State, Nigeria.MethodsA total of 300 nasal swabs of poultry farmers and butchers in slaughters from New Layout Market and Josephine Elechi Poultry Farm were analyzed in the Microbiology Laboratory Unit of Ebonyi State University.ResultsResults showed that Staphylococcus aureus occurrence rates were 20% (poultry farm A), 17% (poultry farm B), 15% (poultry slaughter A), and 16% (poultry slaughter B). Methicillin-resistant Staphylococcus aureus (MRSA) prevalence rates were 11% (39 handlers) and 14% (39 butchers). Antibiotic sensitivity tests revealed high resistance to lincomycin (100%), clindamycin (100%), doxycycline (94.7%), vancomycin (89.5%), erythromycin (89.5%), trimethoprim (73.3%), and ciprofloxacin (60.5%) in poultry farm A. Poultry Farm B samples exhibited resistance to doxycycline (93%), trimethoprim (72%), vancomycin (86.1%), erythromycin (83.7%), lincomycin (100%), and piperacillin-tazobactam (95.4%). Poultry slaughter A samples displayed resistance to doxycycline (100%), trimethoprim-sulfamethoxazole (80%), vancomycin (86.7%), erythromycin (93.3%), lincomycin (100%), and clindamycin (100%), while samples from poultry slaughter B showed resistance to erythromycin (100%), lincomycin (100%), clindamycin (100%), doxycycline (92.6%), vancomycin (88.9%), and trimethoprim-sulfamethoxazole (74.1%). Multiple antibiotics resistance index (MARI) was 0.7 among poultry farmers and 0.6 among poultry butchers provokes great concern.ConclusionTherefore, our findings emphasized the importance of judicious antibiotic use and preventive measures to control MRSA spread in the poultry industry.