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Draft metagenome-assembled genomes of Pseudomonas putida isolated from human gut microbiome in Nasarawa State, Nigeria

Anunobi, Oluchukwu Ogechukwu

Department of Biochemistry, Faculty of Science, Bingham University, Karu, Nasarawa State, Nigeria

Correspondence to: oluchukwu.anunobi@binghamuni.edu.ng; 07034439524; ORCID: 0000-0003-2047-5313

Abstract:
The metagenome-assembled genome (MAG) sequences of Pseudomonas putida PP14A and PP20A were obtained by metagenomic sequencing from the gut microbiomes of a female and a male patient both 24 years old from the same household presenting to a health outreach laboratory with complaint of headache, and occasional diarrhoea in Mararaba, Nasarawa State, Nigeria. The phylogenetic relationship observed between the two PP MAGs with other Pseudomonas spp MAGs from human, points to the global spread of Pseudomonas putida through human activity and migration. Continue reading “Draft metagenome-assembled genomes of Pseudomonas putida isolated from human gut microbiome in Nasarawa State, Nigeria”

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Phylogenetic variants of Mycoplasma hominis from pregnant women and women presenting with infertility in Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria

 1Chukwuka, C. P., 2Emele, F. E., 3Agbakoba, N. R., *1Ezeagwuna, D. A., and 4Oguejiofor, C. B.

 1Department of Medical Microbiology and Parasitology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria

2Department of Medical Microbiology and Parasitology, Nnamdi Azikiwe University, Nnewi, Anambra State, Nigeria

3Department of Medical Laboratory Science, College of Health Sciences, Nnamdi Azikiwe University, Nnewi Campus Nnewi, Anambra State, Nigeria

4Department of Obstetrics and Gynecology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi Campus, Nnewi, Anambra State, Nigeria

*Correspondence to: dorrezeagwuna@gmail.com; 08037745700 & 07088454383; ORCID-0000-0003-2259-720X

 

Abstract:

Background: Much controversies have been associated with the pathogenicity of Mycoplasma hominis but little has been done to unravel the mystery behind the different views. This study aimed at investigating the genetic variants abounding within M. hominis and the distribution of the virulent genes among the variants.

Methodology: Twenty (20) M. hominis isolates from high vaginal swabs of women (11 from pregnant women and 9 from women presenting with infertility) attending the Obstetrics and Gynaecology clinics of Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nigeria, were sequenced using 16S rRNA universal gene target for the purpose of phylogenetic analysis and epidemiological typing. The isolates were also screened for the presence of M. hominis variable adherence antigen (vaa) and p120 virulent genes using primer constructs from the respective genes in a conventional PCR protocol. Continue reading “Phylogenetic variants of Mycoplasma hominis from pregnant women and women presenting with infertility in Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria”

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Correlation of methicillin resistance and virulence genes of Staphylococcus aureus with infection types and mode of acquisition in Sofia, Bulgaria

1*Gergova, R. T., 1Tsitou, V. S., 2Gergova, I. I., 1Muhtarova, A. A., and 1Mitov, I. G.
1Department of Medical Microbiology, Faculty of Medicine, Medical University of Sofia, 2 Zdrave str., 1431-Sofia, Bulgaria
2Department of Military Epidemiology and Hygiene, Military Medical Academy, Sofia, Bulgaria *Correspondence to: rtgergova@gmail.com; +35929172547

Abstract:
Background: Infections due to methicillin resistant Staphylococcus aureus (MRSA) which is the most virulent species among the staphylococci have become a global health challenge. The aim of this study was to assess the correlation of genes encoding virulence and methicillin resistance in invasive and non-invasive isolates from inpatients/outpatients with staphylococcal infections in Sofia, Bulgaria. Materials and methods: Non-duplicate S. aureus isolates were recovered from clinical samples obtained from a total of 368 in-patients with healthcare-associated infections and outpatients with community acquired infections, following overnight cultures of samples on Columbia agar with 5% sheep blood at 35°C. The isolates were presumptively identified by colony and Gram stain morphology, positive catalase reaction and plasma-coagulase test. Isolates were screened for methicillin resistance by the cefoxitin disk method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) protocol. The mecA and mecC, and 12 staphylococcal virulence genes were detected by a combination of monoplex and multiplex polymerase chain reaction (PCR) assays.
Results: The prevalence of MRSA based on carriage of mecA gene was 12%; 7.7% for outpatients and 16.2% for inpatients (p<0.05). The frequency of toxin genes detection in the staphylococcal isolates were as follows; sei (72.6%), seb (59.8%), seh (41.3%), sec (38.3%), seg (37.5%), sej (32.3%), sea (26.6%), sed (10.3%), tst (6.5%), and see (4.3%). The virulence genes, tst, sea, seb, sec, seg, seh and sei were more frequently associated with MRSA than methicillin sensitive (MSSA) strains (p<0.05). About one-third of the clinical S. aureus isolates harbored seven virulence genes; sea, seb, sec, see, seg, seh and sei, that were detected significantly more among the invasive isolates (p<0.05).
Conclusions: This study shows the occurrence of highly virulent staphylococcal isolates in our geographical region.

Key words: Staphylococcus aureus, virulence, methicillin resistance

Received May 17, 2019; Revised June 5, 2019; Accepted June 7, 2019 Copyright 2019 AJCEM Open Access. This article is licensed and distributed under the terms of the Creative Commons Attrition 4.0 International License (//creativecommmons.org/licenses/by/4.0), which permits unrestricted use, distribution and reproduction in any medium, provided credit is given to the original author(s) and the source.

Corrélation des gènes de résistance à la méthicilline et de virulence de Staphylococcus aureus avec les types d’infection et le mode d’acquisition à Sofia, Bulgarie

1*Gergova, R. T., 1Tsitou, V. S., 2Gergova, I. I., 1Muhtarova, A. A., et 1Mitov, I. G.
1Département de microbiologie médicale, Faculté de médecine,
Université médicale de Sofia, 2, Zdrave str., 1431-Sofia, Bulgarie
2Département d’épidémiologie et d’hygiène militaires, Académie de médecine militaire, Sofia, Bulgarie *Correspondence à: rtgergova@gmail.com; +35929172547

Abstrait:

Contexte: Les infections dues à Staphylococcus aureus résistant à la méthicilline (SARM) l’espèce la plus virulente parmi les staphylocoques, sont devenues un problème de santé mondial. Le but de cette étude était
Methicillin resistance and virulence genes of S. aureus Afr. J. Clin. Exper. Microbiol. 2019; 20 (4): 280-288
281
d’évaluer la corrélation des gènes qui codant pour la virulence et la résistance à la méthicilline avec des isolats invasifs ou non invasifs de patients hospitalisés/ambulatoires patients infectés par le staphylocoque dans Sofia, Bulgarie. Matériels et méthodes: Des isolats de S. aureus non dupliqués ont été récupérés à partir d’échantillons cliniques prélevés chez 368 patients atteints d’infections associées aux soins de santé et de patients ambulatoires présentant des infections acquises en communauté, après avoir effectué des cultures pendant la nuit d’échantillons sur de la gélose Columbia contenant 5% de sang de mouton à 35°C. Les isolats ont été présumés identifiés par la morphologie de la colonie et de la coloration de Gram, la réaction positive à la catalase et le test plasma-coagulase. Les isolats ont été criblés pour la résistance à la méthicilline par la méthode de la céfoxitine selon le protocole du Comité européen sur les tests de sensibilité aux antimicrobiens (EUCAST). Les gènes mecA et mecC, ainsi que 12 gènes de virulence staphylococcique ont été détectés par une combinaison de tests de réaction en chaîne de la polymérase (PCR) monoplex et multiplex. Résultats: La prévalence de SARM basée sur le portage du gène mecA était de 12%; 7,7% pour les patients ambulatoires et 16,2% pour les patients hospitalisés (p<0,05). La fréquence de détection des gènes de toxines dans les isolats de staphylocoques était la suivante: sei (72,6%), seb (59,8%), seh (41,3%), sec (38,3%), seg (37,5%), sej (32,3%), sea (26,6%), sed (10,3%), tst (6,5%) et see (4,3%). Les gènes de virulence, tst, sea, seb, sec, seg, seh et sei étaient plus fréquemment associés à SARM que les souches sensibles à la méthicilline (MSSA) (p<0,05). Environ un tiers des isolats cliniques de S. aureus portaient sept gènes de virulence; sea, seb, sec, see, seg, seh et sei, qui ont été détectés significativement plus parmi les isolats invasifs (p<0,05). Conclusion: Cela crée un risque de propagation d’isolats très virulents dans la région géographique

Mots-clés: Staphylococcus aureus, virulence, résistance à la méthicilline

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Correlation of methicillin resistance and virulence genes of Staphylococcus aureus with infection types and mode of acquisition in Sofia, Bulgaria

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Molecular detection of salmonella species from selected vegetables sold in a north-central Nigerian setting

D.S. Adeniyi, T.M. Akindigh, F.N. Aniweta, H.J. Zumbes, A.J. Anejo-okopi

 

Abstract

It is vital to study and understand the genetic basis to the virulence of different Salmonella strains in other to fully grasp the facts behind the unique capabilities of these pathogenic agents to causing diseases in both humans and animals. In this study, the conventional microbiological culture methods were used to isolate pure Salmonella strains from 120 vegetable samples of five different types; which were all obtained at seven different popular markets in the Jos Metropolis of North Central Nigeria. 25 (20.8%) pure isolates were obtained from 120 samples after initial culture and sub-cultures; with 24 (20%) of the pure isolates testing positive as being pathogenic after biochemical analysis. From the 25 pure isolates, the same 24 which tested positive for biochemical tests were also successfully amplified by PCR technique with the SalmonellainvA virulence gene. The result shows that 96% of the pure isolates were positive for the Salmonella invA gene. The PCR product which was very specific is a 250bp fragment of DNA which was visualized in 1.5% agarose gel. This finding shows that virulent Salmonella strains pose a major health hazard and public health concern to the affected population. Our study shows that there is a high prevalence rate of virulent Salmonella strains in North-Central Nigeria. It is thus concluded that although both the conventional culture and biochemical methods of isolating Salmonella species are most useful for obtaining pure isolates and identifying pathogenic strains, however, the PCR technique remains the most specific and sensitive; especially when the rapid identification and detection of virulent strains of Salmonella species are of utmost importance.

Keywords: Virulence, invA gene, PCR, North Central Nigeria

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Molecular detection of salmonella species from selected vegetables sold in a north-central Nigerian setting

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A review of the virulence factors of pathogenic fungi

C. Iyalla

 

Abstract

Fungal infections are becoming more prevalent especially with increase in immunodeficiency disorders, immunosuppression following transplantation, cancers and cancer treatment. They are ubiquitous and cause infections which may be trivial or more deep seated and severe infections associated with mortality. The ability of some fungal species to cause disease is due to various virulence factors which help with fungal survival and persistence in the host resulting in tissue damage and disease. This review discusses these virulence factors. These factors include an ability to adhere to hosts’ tissues, production of enzymes that cause tissue damage and direct interference with host defences. Pathogenic fungi produce catalases and Mannitol which protect against reactive oxygen species (ROS). Some fungi notably, dimorphic fungi and C. albicans have the ability to switch from one form to another. Thermotolerance, at least to 370C, is critical for survival in mammalian host and contributes to dissemination. Melanin is produced by a number of pathogenic fungi, and protects against harsh conditions such as UV radiation, increased temperature and ROS. The ability to obtain Iron (Fe) from the storage or transport forms in the host is also a virulence factor and calcineurin acts as a sensor for pathogenic fungi.

Keywords: Fungi, virulence, pathogenic, infections, dimorphism, thermotolerance

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A review of the virulence factors of pathogenic fungi