Detection and significance of anti-Mycobacterium tuberculosis specific IgG antibody response for the diagnosis of pulmonary tuberculosis using enzyme-linked immunosorbent assay
Objective: Evaluation of an ELISA test for detection of IgG antibody response using in-house prepared Mycobacterium tuberculosis H37Rv soluble extract (MTSE) as antigen for rapid diagnosis of pulmonary tuberculosis and its clinical usefulness.
Methods: In this study a total of 758 pulmonary tuberculosis (TB) patients (652 AFB-positive and 106 AFB-negative) 276 healthy controls and 43 pulmonary infectious disease controls other than TB were recruited. IgG antibody level against MTB soluble extract was measured in sera samples of all study groups using an ELISA test. The level of IgG antibody responses was compared among groups by the Kruskal-Wallis test. The pairwise comparison was made by the Mann-Whitney test A positive score was represented by optical density above the cut–off value which was calculated from OD values of healthy controls by adding 2SD to the mean OD value. The evaluation of diagnostic value was considered based on sensitivity and specificity.
Results: Significantly higher levels of IgG antibody response were observed in PTB patients compared to healthy control and non-TB other pulmonary infectious disease control groups (p value<0.0001). The percent positivity for the IgG antibody response was higher in AFB-positive 574/652 (88.04%) and 79/106 (74.53%) AFB-negative PTB patients as compared to healthy control 9/276 (3.26%) and non-TB other pulmonary infectious disease control 3/43 (6.97%). The sensitivity of the test in PTB patients (AFB-positive and AFB-negative) was 86.15% (95% CI; 83.48-88.53) and the specificity was 96.74% (95% CI; 93.90-98.50).
Conclusion: This developed immunological test could be an efficient test in detecting IgG antibody response in PTB patients. Further this test could be useful for diagnosing AFB-negative presumptive TB cases.
Xanthomonas citri pv. eucalyptorum 4866-2_S43 strain (formerly X. axonopodis pv. eucalyptorum): Causal agent of bacterial leaf blight on eucalypt recovered in Argentina
We report here a draft genome assembly of strain 4866-2_S43 isolated from a eucalyptus lesion in Argentina and what until recently was caused by Xanthomonas axonopodis pv. eucalyptorum (Xae). The genome size is 5188607 bp with a G+C content of 64.66%. Comparative analysis reveals that the closest relative of strain 4866-2_S43 is Xae LPF 602 isolated in Brazil. Comparison of the whole genome sequences revealed an average nucleotide identity (ANI) of 99.96%. between the two strains. ANIs were determined between the whole genome sequence of strain 4866-2_S43 and the genomes of all currently validated Xanthomonas spp. These results revealed that strain 4866-2_S43 had greater than 95% with X. citri pv. citri and X. citri pv. phaseoli and less than 95% with X. euvesicatoria pv. alfalfae X. perforans and X. euvesicatoria pathovars euvesicatoria and eucalyptii.
PATHOGENECITY AND ENZYME SCREENING OF SOME SELECTED NON-DERMATOPHYTIC MOLDS
A total of 10 non-dermatophytic molds isolated from both symptomatic and asymptomatic cattle skin which includes Penicillum citrinum Aspergillus welwitschiae Aspergillus aculeatus Curvularia kusanol Cladosporium teniussmum Pestalotiopsis microspora Fusarium oxysporum Fusarium linchenicola Absidia sp. and Aspergillus fumigatuswere subjected to a pathogenicity test using albino mice. These isolates were also screened for five enzymes using standard plate method. Result from pathogenicity test showed that Absidia sp C. tenuissimum and Aspergillus welwitschiae were able to elicit discoloration lesion production and alopecia on the albino mice skin respectively which are evidences of clinical symptoms associated of cutaneous mycoses. The enzyme screening results revealed the highest zone of activity for keratinase (65mm) amylase (86mm) protease (60mm) lipase (60mm) and cellulase (86mm) which were observed on P. microspora A. welwitschiae C. tenuissimum A. welwitschiae and A. welwitschiae respectively. Pathogenicity test from this study shows that some of these molds may be virulent and that can be attributed to their ability to possess some virulent factors which includes secretion of hydrolytic enzymes.
Inducible clindamycin resistance among clinical Gram-positive cocci in a tertiary hospital in Niger Republic
Background. Macrolide-induced resistance to clindamycin is a well-described mechanism leading to treatment failure. Herein we determined the frequency and associated factors of inducible clindamycin resistance in Gram-positive cocci in a tertiary care hospital.
Methods. A cross-sectional descriptive study was carried out between January and December 2022. D tests were performed as recommended by EUCAST 2021 guidelines on 100 non-duplicate clinical isolates of Gram-positive cocci to determine the prevalence of methicillin resistance and inducible clindamycin resistance among the collected isolates.
Results. Of the 100 Gram-positive cocci isolates 56 (56.0 %) 17 (17.0 %) and 27 (27.0 %) were respectively coagulase-negative staphylococci Staphylococcus aureus and Streptococcus spp. Among Streptococcus spp. Group D Streptococci (15.0%) were the most isolated. Methicillin-resistant Staphylococcus aureus (MRSA) represented 9 (53.0 %) of S.aureus isolates. Constitutive (cMLSb) and inducible clindamycin resistance (iMLSb) phenotypes were detected in 36 (36.0%) and 14 (140%) of the isolates respectively. S. aureus exhibited 38.4% of cMLSb and 13.7% of iMLSb. The result of multivariate analysis showed that age groups gender type of samples provenance and bacteria were not significantly associated with Gram-positive cocci iMLSb phenotype.
Conclusion. The study reported for the first time a high prevalence of inducible resistance of Gram-positive cocci strains to clindamycin in Niger Republic. This suggests the urgent need for the implementation of regular screening of these isolates and the wise use of clindamycin in clinical practice.
Erysipelothrix spp. and other Erysipelotrichales detected by 16S rRNA microbial community profiling in samples from healthy conventionally reared chickens and their environment
Outbreaks of erysipelas a disease caused by infection with Erysipelothrix rhusiopathiae (ER) is a re-emerging problem in cage-free laying hen flocks. The source of ER infection in hens is usually unknown and serological evidence has indicated the presence of ER or other antigenically related bacteria also in healthy flocks. The aim of the present study was to evaluate sample collection culture methods and DNA-based methodology to detect ER and other Erysipelotrichales in samples from healthy chickens and their environment.
We used samples from a research facility with conventionally reared chickens with no history of erysipelas outbreaks where hens with high titers of IgY recognising ER previously have been observed. Microbial DNA was extracted from samples either directly or after pre-culture in nonselective or ER-selective medium. Real-time PCR was used for detection of Erysipelothrix spp. and high-throughput amplicon sequencing of 16S rRNA sequencing was used for detection of Erysipelotrichales. A pilot serological analysis of some Erysipelotrichales members with IgY from unvaccinated and ER vaccinated high biosecurity-chickens as well as conventionally reared chickens was also performed.
All samples were negative for ER E. tonsillarum and E. piscisicarius by PCR analysis. However 16S rRNA community profiling indicated the presence of several Erysipelotrichales genera in both environmental samples and chicken intestinal samples including Erysipelothrix spp. that were detected in environmental samples. Sequences from Erysipelothrix spp. were most frequently detected in samples pre-cultured in ER-selective medium. On species level the presence of E. anatis and/or E. aquatica was indicated. Serological results indicated that IgY raised to ER showed some cross-reactivity with E. anatis. Hence environmental samples pre-cultured in selective medium and analysis by 16S rRNA sequencing proved a useful method for detection of Erysipelotrichales including Erysipelothrix spp. in chicken flocks. The observation of such bacteria in environmental samples offers a possible explanation for the observation of high antibody titres to ER in flocks without a history of clinical erysipelas.
Galleria mellonella as a superficial model for Malassezia globosa and its treatment
Introduction. Malassezia globosa is a yeast species that belongs to the mycobiota of humans and animals associated with dermatological disorders such as dandruff. This is a chronic scalp skin disorder characterized by flaking and itching. Treatments include commercial shampoo with different formulations that contain antifungal activities like Zinc pyrithione or Piroctone Olamine. The effectiveness of these formulations have been evaluated for decades for dandruff symptom relief of volunteers. To date non-mammalian in-vivo methods exist to test formulations of these actives.
Aim. To evaluate in vivo in Galleria mellonella larva two commercial antifungal shampoos (Shampoo with 1% ZPT & 1.6% Zinc Carbonate and shampoo with 0.5% PO) against this species.
Methodology. G. mellonella larvae were inoculated with M. globosa on abraded cuticular surface. Then integument cell viability histological changes and fungal burden were evaluated.
Results. Larvae inoculated with M. globosa showed higher lesion melanization and tissue damage. In addition M. globosa population showed to increase over time. Concerning the shampoo’s effectiveness both formulations significantly reduced M. globosa burden and tissue damage.
Conclusion. G. mellonella larvae were allowed to evaluate M. globosa superficial infection and antifungal effectiveness. Shampoos with ZPT and PO showed a positive effect on inoculated larvae.
Retrospective analysis of Acinetobacter baumannii bacteraemia risk factors, complications, and mortality in a tertiary university hospital in Saudi Arabia
Introduction. Acinetobacter baumannii is a nosocomial pathogen of which many isolates are multidrug resistant. A. baumannii is a major cause of healthcare-acquired infections in patients who are critically ill and A. baumannii bacteraemia (ABB) is associated with high mortality. Several factors are known to play a role in A. baumannii transmission and the emergence of resistance.
Aim. This study aimed to retrospectively analyse ABB cases in Saudi Arabia where little is known about the prevalence risk factors clinical disease treatment outcomes and mortality associated with this infection.
Methods. A retrospective chart review was performed from January 1 2015 until December 31 2022 to identify all patients 14 years and above with ABB. Demographic and clinical data as well as results from laboratory analyses were collected from patients’ electronic charts. Statistical analyses were performed on the data to identify factors associated with 90-day mortality.
Results. In total 112 ABB cases were identified with a mean age of 58.0 years of which 66.1% were males. Of these cases 71 (63.4%) died. The factors that were found to be associated with 90-day mortality were the Charlson comorbidity score Pitt bacteraemia score quick Sequential Organ Failure Assessment (qSOFA) score (p < 0.001 for each) hospital ward (p < 0.02) short duration of antibiotic treatment (p < 0.01) and higher age (p < 0.05). The most common source of infection was Central Line-associated Bloodstream Infection in 52.7%. Also associated with mortality were inappropriate antimicrobial therapy (p < 0.02) and empirical use of colistin (p < 0.05). In many patients ABB was caused by carbapenem-resistant A. baumannii (CRAB) (69.6%) and 74.4% of those patients died.
Conclusion. CRAB is a growing threat in hospitals in Saudi Arabia especially in the critical care setting and carries a very high risk of mortality. Future studies should focus on novel ways of preventing CRAB infections and on the assessment of promising new antimicrobials such as cefiderocol or sulbactam-durlobactam and other treatment options such as bacteriophages.
Fatal Clostridium septicum gas gangrene complicating ECMO : case report and review of literature
Clostridium septicum gas gangrene is a severe and deadly infection caused by an anaerobic spore-forming Gram-positive bacillus. As previously described two entities are observed: traumatic and spontaneous (or non-traumatic) forms. In this report we aim to describe the case of a fulminant and ultimately fatal C. septicum myonecrosis occurring in a patient who was first admitted for refractory cardiac arrest and placed on veino-arterial extracorporeal membrane oxygenation (ECMO). Building upon prior studies that have documented cases of spontaneous gas gangrene caused by C. septicum we provide an updated compilation focusing on microbiological characteristics of C. septicum along with the diagnostic and therapeutic challenges associated with spontaneous gas gangrene. Additionally the specific clinical situation of our case illustrates the seriousness of this infectious complication that combined both spontaneous and traumatic gas gangrene risk factors. We thus discuss the antibiotic coverage prior to the initiation of ECMO procedure.
Isolation of Bioactive Compounds from Low-cost Agricultural Resources and its Utilization in Daily Life.
The ethanolic (80%) methanolic (80%) and aqueous decoction (100% distilled water) of whole plant of Oxalis corniculata Linn (Indian Sorrel) was evaluated for its anti‐microbial and antioxidant properties by in vitro methods. Methanolic (80%) and ethanolic (80%) decoctions showed significant antibacterial property against Staphylococcus aureus Bacillus subtilis Escherichia coli Salmonella typhi bacterial strains. In comparison to Chloramphenicol (C30) against bacteria 80% ethanolic decoctions showed significant effect among the decoctions. Nowadays though the standard soap is in a huge demand but it’s also facing major backlashes due to the presence of synthetic compounds in it which over long use may cause harmful effects on the skin health. Therefore the organic soaps which are made up of natural ingredients herbs or any sort ayurvedic compound have less side effects on the human skin and are much safer than standard daily soap. The formulated therapeutic soap exhibits significant amount of reducing potential (high FRAP and TAC values) and antioxidant activity (DPPH ABTS assay).
Identification of anaerobic and aerobic bacteria that can be associated with DFI and their therapeutic in Elnaw teaching hospital
Diabetic foot infection (DFI) is one of the commonest diabetic complications which considered a major public health concern around the world with the rising prevalence especially in developing countries. Globally adults with diabetes accounted for 463 million in 2019 according to the International Diabetes Federation.
The aim of this study was to identify the anaerobic and aerobic bacteria that causing DFI and their therapeutic regimen on diabetic patients in diabetic clinic room in Elnaw teaching hospital - Khartoum state.
The study showed that there was no infection by anaerobic organism and the most frequently isolated organisms were gram negative rods (70%) which represents (65%) on diabetic patients. The commonest isolated organism was S.aureus (30%) followed by E.coli (25%) in control group (non-diabetic) while Klebsiella.spp and S.aureus with (20%) for each; were isolated from the clinic room swabs.
Early diagnosis optimal management and effective antibiotic therapy are necessary to prevent DFI and amputation.
ELISA for leptospiral 3-hydroxyacyl-CoA dehydrogenase in urine is a promising screening tool for acute leptospirosis
Introduction: Leptospirosis is a zoonotic disease that is prevalent worldwide. The leptospiral 3-hydroxyacyl-CoA dehydrogenase (3-HADH) is excreted in the urine of infected individuals. However the potential use of 3-HADH as a biomarker for the diagnosis of leptospirosis using enzyme-linked immunosorbent assay (ELISA) has not been investigated. A technique that identifies Leptospira in a patient in urine sample will be valuable in regular diagnostics and epidemic scenarios as opposed to existing serological approaches. This study aimed to develop and evaluate an ELISA that can detect 3-HADH in the urine of patients with confirmed acute leptospirosis and to assess its potential as a screening test for leptospirosis.
Methods: Laboratory confirmation of acute leptospirosis was done by flaB-nested polymerase chain reaction (PCR) of plasma samples from suspected patients. ELISA-based determination of the presence of 3-HADH in the urine of PCR-positive patients versus PCR-negative patients matched for fever date was performed by coating ELISA plates with urine supernatants and using rabbit anti-3-HADH as the primary antibody. Receiver operating characteristic curve analysis was used to determine the cutoff values for the ELISA. The diagnostic measures between the PCR-positive and PCR-negative patients were compared using the Mann-Whitney U test.
Results: In total 158 febrile patients were assessed of whom 121 (76.6%) were male. Of the 15 flaB-nested PCR-positive patients 12 were in the acute phase of the febrile illness. The best cutoff was an average optical density (ODav) value of 0.2200 for febrile patients. Sensitivity and specificity were 83.33% (95% confidence interval [CI] 51.59–97.91%) and 83.33% (95% CI 76.05–89.13%) respectively. The ODav values for PCR-positive patients in the acute phase of the disease (≤7 days of fever) were significantly higher than those for PCR-negative patients (p<0.001 U=114.0 z= -4.946).
Conclusion: Detection of 3-HADH in urine by ELISA appears promising for the screening of acute leptospirosis in suspected patients.
A Case of Persistent Pasteurella Multocida Cellulitis Complicated with Large Endocarditis Vegetation
Introduction: A distinct and infrequent player emerges in the realm of infective endocarditis Pasteurella multocida now warranting careful consideration in this unique case report. Disseminated P.multocida infection seeded into the heart valve has only been reported in about one case per year worldwide with only 42 cases were found in the literature and only 5 cases reported to have underlying liver cirrhosis as in our case.
Case Presentation: A 73-year-old female with past medical history of liver cirrhosis secondary to primary biliary cholangitis with splenomegaly and pancytopenia presented to hospital with weakness fever and leg rash. She had recent admission with lower extremity cellulitis and P.multocida bacteremia treated with 14 days high dose oral amoxicillin-clavulanate after negative blood culture prior to discharge. The repeat blood culture showed P.multocida. Echocardiogram showed a 1.9 cm x 1 cm mobile mass attached to the mitral valve. She was not a suitable candidate for valve surgery due to her comorbidities. She was ultimately discharged with a two-week course of ceftriaxone continued with levofloxacin to complete six weeks of total treatment and followed by long-term penicillin.
Conclusion: In this case report we delve into a rare clinical presentation of Pasteurella multocida case. Our patient is the second reported case which showed complication of native mitral valve endocarditis even in the setting of bacteremia resolution. This report sheds light on the challenging diagnosis and management of this uncommon yet clinically significant condition highlighting the importance of vigilant and prompt intervention in endocarditis cases with atypical agents.
Cutaneous tuberculosis an unusual localization: A case report
Tuberculosis is a major public health concern. Morocco is a tuberculosis endemic country; nearly 30000 cases are recorded each year. Pulmonary tuberculosis accounts for 57% extrapulmonary tuberculosis 43%. Cutaneous localization is exceptional; it accounts for 0.5% to 2% of cases of tuberculosis. It is very difficult to diagnose given the variability of clinical presentation. We report a rare case of cutaneous tuberculosis in a patient with a history of pulmonary and cutaneous sarcoidosis.
Bloodstream infections in cancer patients in central India: study of pathogens and trend of antimicrobial resistance over five years
Bloodstream infection (BSI) is a prevalent complication with a high fatality rate in cancer patients. Over time and in different countries there are noticeable changing trends in the epidemiology of BSI. With this context our goal was to investigate the antibiogram and distribution of bacterial pathogens causing BSI in central Indian cancer patients. This single-center retrospective observational study was conducted in an Indian cancer hospital that offers tertiary care. Patients with solid organ and haematological cancers in both adults and children who had blood cultures sent to the microbiology laboratory were all included. In accordance with the recommendations of the Clinical and Laboratory Standards Institute (CLSI) blood cultures were processed using the BacT/ALERT 3D system (BioMerieux France) and identification of bacteria to species level and antimicrobial susceptibility (AST) was carried out using the Vitek 2 compact system (BioMerieux France). Electronic medical records and microbiology lab records were used to retrieve the demographic and microbiological data. Microsoft Excel (Microsoft Excel RRID: SCR_016137) was used to enter and tabulate the data while SPSS (RRID: SCR_002865) was used to conduct the statistical analysis. Hemato-lymphoid cancer had a higher culture positive rate than solid organ cancer. In cancer patients BSI was more frequently caused by gram-negative bacteria.
An improved genome editing system for Sphingomonadaceae
The sphingomonads encompass a diverse group of bacteria within the Sphingomonadaceae family with the presence of sphingolipids on their cell surface instead of lipopolysaccharide as their main common feature. They are particularly interesting for bioremediation purposes due to their capability to degrade or metabolise a variety of recalcitrant organic pollutants. However the research and development of their full bioremediation potential has been hampered because of the limited number of tools available to investigate and modify their genome. Here we present a markerless genome editing method for Sphingopyxis granuli which can be further optimised for other sphingomonads. This procedure is based on a double recombination triggered by a DNA double strand break in the chromosome. The strength of this protocol lies in forcing the second recombination rather than favouring it by pressing a counterselection marker thus avoiding laborious re-streaking or passaging screenings. Additionally we introduce a modification with respect to the original protocol to increase the efficiency of the screening after the first recombination event. We show this procedure step by step and compare our modified method with respect to the original one by deleting ecfG2 the master regulator of the general stress response in S. granuli. This adds onto the genetic tool repertoire that can be applied to sphingomonads and stands as an efficient option for fast genome editing of this bacterial group.
Seroprevalence of Herpes simplex virus Type-1 IgG antibodies among pregnant women with recurrent abortions
Herpes Simplex Virus Type 1 (HSV-1) is a nuclear replicating enveloped virus usually acquired through direct contact with infected lesions or body fluids (typically saliva). The prevalence of HSV-1 infection increases progressively from childhood and inversely related to socioeconomic background. The infections among children are either asymptomatic or following an incubation period of about 1 week gives rise to mucocutaneous vesicular eruptions. Herpetic gingivostomatitis typically affects the tongue lips gingival buccal mucosa and the hard and soft palate. The main aim of this study is to study the seroprevalence of herpes simplex virus type-1 IgG antibodies among pregnant women with recurrent abortions. The study demonstrated a 29 (58%) were positive HSV-1-IgG and 21 (42%) were negative among cases (pregnant women) while 25 (100%) in control subject were negatives and the possible risk factors i.e. age Abortion Blood transfusion Contraceptive Rash have been examined in this study and showed no effect except previous history of TORCH test examination. The study concluded more than half pregnant women was found to be infected in our study and we recommended to screen both IgM and IgG followed by viral detection and load by molecular technique in case of positive ELISA.
Invasive Streptococcus pyogenes Infection: A case report
The Group A Streptococcus also known as Streptococcus pyogenes is a human pathogen causing various infections ranging from mild such as tonsillitis and impetigo to severe and invasive conditions like septicemia and necrotizing fasciitis. Despite a decline in incidence and severity during the 20th century due to antibiotics there has been a reported increase in severe cases since the 1980s in industrialized countries.
Streptococcus pyogenes (S. pyogenes) is a human pathogen with a natural reservoir in the 26 pharynx and skin exhibits asymptomatic carriage in various body sites. It is responsible for a 27 spectrum of clinical manifestations from asymptomatic carriage to severe invasive infections. 28 Transmission occurs through respiratory droplets or direct contact with skin lesions. 29 Bacteriologically S. pyogenes is a gram-positive β-hemolytic streptococcus. This summary highlights a case of invasive Group A Streptococcus infection in a 28-year-old diagnosed at the microbiology laboratory of the Mohammed V Military Training Hospital in Rabat Morocco.
A 28-year-old patient with a history of chickenpox presented with acute febrile oligoarthritis. Following a recent flu-like syndrome and febrile tonsillitis the patient experienced asymmetric inflammatory oligoarthralgia affecting the left knee left ankle and right shoulder accompanied by functional impairment of the left lower limb. Upon admission clinical examination revealed swelling positive patellar tap and sternal involvement. Laboratory and imaging findings indicated an abscessed collection in the left knee and anterior mediastinitis. Emergency aspirations revealed Group A Streptococcus specifically Streptococcus pyogenes leading to a diagnosis of septic arthritis. Dual antibiotic therapy and knee joint drainage resulted in symptom resolution after 45 days.
The rise in severe Group A Streptococcus infection underscores the need for early detection and treatment. Widely sharing the French High Council for Public Health’s antibiotic prophylaxis recommendations is crucial for awareness. Collaborating between clinicians and microbiologists is essential for effective management.
Phenotypic and genotypic characterization of ESBL Enterobacteriaceae clinical isolates in a Moroccan hospital
Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are a major public health problem in hospitals and in the community. The objective of this work was to describe the epidemiology of ESBL enterobacteria to study their resistance profile and to determine the genes encoding the ESBL phenotype.
This is a retrospective study conducted in the bacteriology laboratory of the Military Hospital of Instruction Mohamed V of Rabat and covering all isolates of Enterobacteriaceae from 01/01/2018 to 31/12/2020. The molecular study of ESBL genes involved a representative sample of all ESBL isolates.
The overall prevalence of ESBLs in isolated Enterobacteriaceae (1402/10268) is 13.65%. The urinary tract was the main site of isolation of ESBL (61%). The bacterial species most concerned are essentially Escherichia coli (419%) Klebsiella pneumoniae (422%) and Enterobacter cloacae (119%). The study of antibiotic susceptibility showed a resistant profile marked mainly by 100% resistance to C1G and C3G 55% to piperacillin-tazobactam 16% to imipenem 87% to fluoroquinolones. Molecular typing of ESBL strains showed a prevalence of CTX-M (95%) SHV (50%) and TEM (56%). The CTX-M-1 and the CTX-M-9 groups were the most common (9619% and 762 % respectively) and CTX-M15 was found in 7810% CTX-M-1 ESBL positive isolates. Most strains had more than two coexisting resistance genes.
The prevalence rate of ESBL-E is critical and preventive action at different levels (prescriber biologist hospital patient etc.) is necessary in order to limit their spread and to manage a better therapeutic strategy.
Molecular characterization of HBV infected Nigerians reveal diverse mutational profiles within the BCP/PC regions
Background; Hepatis B virus (HBV) is the most implicated cause of severe liver disease and hepatocellular carcinoma worldwide. Studies have shown that the basal core protein (BCP) and pre-core protein (PC) of HBV play a significant role in HBV related carcinogenesis. There is paucity of data on type and effect of BCP and PC mutations in Nigeria. This study aims to genotype HBV and investigate any mutations within the BCP and PC among HBV patients in Ibadan Nigeria.
Methods; Forty HBV DNA positive were recruited into this study viral load assay and genotyping by nested multiplex PCR was done. The partial X gene region was amplified and Sanger sequenced. The BPC and PC genomic regions were then analyzed using bioinformatics.
Results; Twenty-three participants recorded HBV DNA viral load of >20000 International Units (IU) while 17 had <20000 IU while 28 samples were genotyped. Five genotypes A B C D and E and 4 mixed genotypes AC AD ACD and ABCD were detected. Genotype AC was the most frequently encountered while genotypes E and B were the least encountered. Mutation was highest in ages 34 to 45 years. Double mutation A1762T and G1764A within the BCP region was the most encountered mutation.
Conclusions; We report a diverse HBV genetic landscape with mixed infections between genotypes with BCP double mutation A1762T/G1764A signaling the likelihood of poor HBV related liver disease prognosis. Our findings contribute to our understanding of the molecular characteristics of HBV and its potential implications for disease progression and management among HBV infected Nigerians.
Comparative genome analyses of Staphylococcus aureus from platelet concentrates reveal rearrangements involving loss of type VII secretion genes
Staphylococcus aureus has been involved in transfusion-transmitted fatalities associated with platelet concentrates (PCs) due to its heightened pathogenicity enhanced by genome-encoded virulence and antibiotic resistance genes. This may be facilitated by mobile genetic elements (MGEs) that can cause rearrangements. Several factors contribute to S. aureus virulence including the type VII secretion system (T7SS) which is comprised of twelve genes six of which form the T7SS core and are conserved across S. aureus strains. In this study we conducted comparative genome analyses of five S. aureus isolates from PCs (CI/BAC/25/13/W PS/BAC/169/17/W and PS/BAC/317/16/W were detected during PCs screening with the BACT/ALERT automated culture system and ATR-20003 and CBS2016-05 were missed during screening and caused septic transfusion reactions). Multiple alignments of the genomes revealed evidence of rearrangements involving phage ɸSa3 in PS/BAC/169/17/W and PS/BAC/317/16/W. While the former had undergone translocation of its immune evasion cluster (IEC) the latter had lost part of the phage leaving behind the IEC. This observation confirms S. aureus genome plasticity. Unexpectedly strain CBS2016-05 was found to encode a pseudo-T7SS that had lost five of the conserved core genes (esxA esaA essA esaB and essB) and contained a 5’ truncated essC. Since these genes are essential for the function of the T7SS protein transport machinery which plays a key role in S. aureus virulence CBS2016-05 probably compensates by recruiting other export mechanisms and/or alternative virulence factors such as neutralizing immunity proteins. This study unravels genome rearrangements in S. aureus isolated from PCs and reports the first S. aureus isolate lacking conserved T7SS core genes.