Papers by Dr. Suliman Essuman
The global health challenge posed by the emergence of antibiotic resistance pathogen is further e... more The global health challenge posed by the emergence of antibiotic resistance pathogen is further exacerbated in African countries by the indiscriminate use of antibiotics, poor surveillance and lack of stewardship programs. To address this issue, we employed the Oxford Nanopore Technologies (ONT) to sequence 17 clinical isolates from a referral hospital in Kenya. Our comprehensive bioinformatics approach facilitated the assembly, identification of sequence types and prediction of antimicrobial resistance genes, mobile genetic elements (plasmids and integrons) and virulence genes. Of the 17 isolates, five wereA. baumannii, fourE. coli, threeS. haemolyticus, three wereE. cloacae,whileS. aureusandE. faecaliswere single isolates. For the detection of AMR genes,A. baumanniiisolates harbored genes such asblaOXA-23which mediates resistance to carbapenems,E. coliandE. cloacaecarriedblaCTX-M-15which confers resistance to cephalosporins andS. haemolyticusharboredblaZ,responsible for resistance...
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International Journal of Tropical Insect Science, 1997
RésuméL’hémolymphe des criquets migrateurs, Schistocerca gregaria et Locusta migratoria contient ... more RésuméL’hémolymphe des criquets migrateurs, Schistocerca gregaria et Locusta migratoria contient des facteurs humoraux, la lectine et le système phénoloxydase. Ces facteurs ont été mis en évidence par des tests in vitro. La lectine présente dans le plasma agglutine les hématies de lapin et les protozoaires Malamoeba locustae, Leishmania major et Trypanosoma brucei. Sa purification et son analyse par électrophorèse en conditions dénaturantes et non dénaturantes ont révélé qu’il s’agit d’une protéine de 650 kD composée de sous-unités de 80 kD. Le système phénoloxydase a été également étudié. Il peut être activé in vitro par des substances d’origine microbienne (LPS, laminarine, suspension de kystes de M. locustae), par la trypsine ou le méthanol. Les inhibiteurs de ces deux facteurs humoraux ont été étudiés. Dans le cas de la lectine, il s’agit du sucre inhibiteur, le nitrophényl ± d-galactopyranoside et l’antisérum antilectine. Des inhibiteurs du système phénoloxydase ont été identifiés dans le plasma. Les perspectives d’utilisation de ces inhibiteurs dans la lutte biologique sont discutées. En effet, il serait intéressant d’étudier les possibilités de leur incorporation dans la formulation des biopesticides; ils pourraient ainsi exercer une action dépressive sur le système immunitaire de l’insecte tout en amplifiant l’action des biopesticides.AbstractHaemolymph from the locusts Schistocerca gregaria and Locusta migratoria contains humoral factors such as lectin and phenoloxidase system. In vitro studies demonstrated that phenoloxidase system can be activated by LPS, laminarin, Malamoeba locustae cysts, trypsin and methanol. Haemolymph showed agglutination activity for mammalian erythrocytes and protozoa (M. locustae, Leishmania major and Trypanosoma brucei). A purified lectin was isolated from haemolymph by affinity chromatography. Analysis by SDS-PAGE gave a single band at 80 kD while on native PAGE, it gave a single band at 650 kD. Inhibitors of the two humoral factors were investigated. Lectin activity was inhibited by nitrophenyl ± d-galactopyranoside in both cases and by lectin antiserum. Inhibitors of the phenoloxidase system were found in plasma. Prospects for use of such inhibitors are discussed. They could be incorporated in biopesticide formulations in such a way that they could depress locust immune reaction and stimulate biocide activity.
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International Journal of Biochemistry Research & Review, 2017
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Journal of Medical Entomology, Jul 1, 1996
A study was conducted using rabbits to ascertain the effects of immunity induced with salivary gl... more A study was conducted using rabbits to ascertain the effects of immunity induced with salivary gland antigens (SGA) on naturally acquired host resistance, which was confirmed by exposing groups of rabbits to adult Rhipicephalus appendiculatus (Neumann) ticks. A reciprocal experiment was conducted to establish the effect of naturally acquired resistance on vaccination with SGA. After the acquisition of resistance by either method of vaccination, rabbits were then challenged with the 3 life stages of the tick. Results of the experiment demonstrated 3 phenomena: infestation of rabbits with 60 adult ticks leads to high protection in terms of reduction in the engorged weight against adult ticks, larvae, and nymphs (88.6, 31.5, and 55.9%, respectively); vaccination alone provides 53.9, 29.7, and 35.7% reduction in adult, larval, and nymphal ticks, respectively; and vaccination of rabbits already exposed to adult tick infestation appeared to have no additive immunological benefit above that already provided by adult ticks. Sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting analyses revealed that antibodies with high avidity to SGA were directed to a 39-kDa polypeptide. This polypeptide was not revealed by sera from rabbits that were first infested with adult ticks. Sera from rabbits that were first vaccinated with SGA consistently reacted with the 39-kDa polypeptide. Sera from rabbits that were infested recognized strongly a 42-kDa polypeptide among 5 polypeptides in the SGA. Results of the experiment show that resistance resulting from adult tick infestation is not augmented by immunity caused by vaccination with SGA.
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Medical and Veterinary Entomology, Oct 1, 1994
... HK KIARA 1,* ,; S. ESSUMAN 1 ,; EO OSIR 1 ,; BA OKWAKPAM 2. Article first published online: 7... more ... HK KIARA 1,* ,; S. ESSUMAN 1 ,; EO OSIR 1 ,; BA OKWAKPAM 2. Article first published online: 7 MAR 2008. ... KIARA, HK, ESSUMAN, S., OSIR, EO and OKWAKPAM, BA (1994), Rearing Amblyomma variegatum ticks in the laboratory: a simple technique to enhance attachment. ...
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Journal of Medical Entomology, Sep 1, 1989
Comparative immunogenicity of salivary gland antigens (SGA) derived from adult Rhipicephalus appe... more Comparative immunogenicity of salivary gland antigens (SGA) derived from adult Rhipicephalus appendiculatus (Neumann) and experimental infestations with the three stages of the tick was investigated. The best immunization schedule judged by reduction of engorgement weights and hatchability resulted from nymphal and adult tick infestations. Inoculation of rabbits with SGA in Freund's incomplete adjuvant (FIA) induced immune responses comparable to those associated with larval infestations, but less than those produced by nymphal or adult tick infestations. High antibody titers directed against SGA were detected only in the vaccinated and adult tick-infested rabbits. The results of this experiment suggest that SGA prepared from partially fed ticks can be used in the experimental induction of immunity to ticks and that the antigen has potential as a vaccine against R. appendiculatus ticks.
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International journal of acarology, Jun 1, 1998
Abstract The sequence of proteins synthesized during the feeding of Amblyomma variegatum and humo... more Abstract The sequence of proteins synthesized during the feeding of Amblyomma variegatum and humoral resistance acquired by Boran cattle when exposed to A. variegatum infestations were studied. Resistance was induced by repeatedly infested cattle with all stages of the tick. Salivary gland proteins possibly responsible for the acquired immunity were studied by analysing homogenates of salivary glands (SGA) on 5-20% gradient Sodium dodecylsulphate Polyacrylamide gel electrophoresis (SDS-PAGE) and comparing them to those in the tick saliva (SA) and nymph homogenates (NH). The proteins with Mr 18, 49.5, 55, 67.5 and 160 kDs were found unique for the tick saliva. On the other hand the proteins with molecular weights of about 17, 33, 27 and 66 kDs, which seemed to have been synthesized at different times during the feeding process, were only found in SGA. When SDS-PAGE was followed with immunobloting, IgG1 subclass isolated from infestation sera recognized prominently two SGA proteins with Mr of about 58 and 5...
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Social Science Research Network, 2021
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International Journal of Tropical Insect Science, Jun 1, 1998
A preliminary survey was conducted in coastal Kenya to assess the hosts of economically important... more A preliminary survey was conducted in coastal Kenya to assess the hosts of economically important tick species (Acari: Ixodidae) of domestic animals, as part of a training course for tick scientists from African research institutions. Ticks were collected from domestic animals in Kilifi and Kwale districts.Eight tick species, namely Amblyomma variegatum, Boophilus decoloratus, B. microplus, R. appendiculatus, R. evertsi evertsi, R. pulchellus, R. simus and A. gemma were identified. Further, more comprehensive surveys on the hosts, distribution and ecology of ticks of economic importance are recommended.RésuméFaisant partie d’un stage destiné aux scientifiques des institutions africaines de recherche sur les tiques de bétail, une enquête préliminaire a été effectuée sur la côte kenyane pour identifier les hôtes des espèces de tiques ayant une importance économique chez les animaux domestiques. Les tiques ont été collectées sur les animaux domestiques dans les districts de Kilifi et Kwale.Huit espèces ont été identifiées dont: Amblyomma variegatum, A. gemma, Boophilus decoloratus, B. microplus, Rhipicephalus appendiculatus, R. evertsi, R. pulchellus et R. simus. Des enquêtes plus poussées sur les hôtes des tiques d’importance économique, leur distribution et leur écologie sont recommandées.
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Science journal of analytical chemistry, 2021
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Journal of Parasitology, Jun 1, 1992
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Experimental and Applied Acarology, Nov 1, 1991
Boran cattle were immunized with a semi-purified fraction (F2) of solubilized membrane-bound anti... more Boran cattle were immunized with a semi-purified fraction (F2) of solubilized membrane-bound antigens extracted from the midgut of the tickRhipicephalus appendiculatus. A subsequent challenge with all stages ofR. appendiculatus showed protection of the cattle to a significant degree. There was a decrease in engorgement weight of ticks, the number which fed above critical engorgement weight was considerably reduced, and about 38% of the larvae which fed to repletion did not moult. The major cause of death of adult female ticks was the increased grooming by cattle as a result of increased dermal irritation.
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Journal of Medical Virology, Oct 1, 1986
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Egyptian Journal of Biochemistry and Molecular Biology, 2011
ABSTRACT Innate immunity plays a key role in the control of microbial infectionsin both vertebrat... more ABSTRACT Innate immunity plays a key role in the control of microbial infectionsin both vertebrates and invertebrates. Haemolymph samples fromShistocerca gregaria, obtained after Trypanosoma brucei brucei challengewere analyzed for their protein profiles using SDS and 2D-PAGE and alsoevaluated for antitrypanosomal activity in vitro. Protein induction wasfound to increase with time, peaking at about 18 hours. In SDS-PAGE, theintensity levels of five polypeptides were found to vary from prechallengelevels. Further analysis of the polypeptides on 2D-PAGE showedvariations in their induction pattern with some being induced, upregulatedor suppressed with time of induction. Samples collected from insectschallenged with parasites followed by sugars, D-glucosamine had thehighest inhibitory effect on the level of protein induction while D-galactosehad the least effect. When screened for trypanolytic activity against T.brucei brucei, the samples had pronounced antitrypanosomal activitywhich peaked with the 18 hour sample. Antibodies raised against Glossinaproteolytic lectin (Gpl), showed no cross-reactivity to Shistocerca gregariainduced haemolymph proteins in Western blots. Antitrypanosoma proteinsinduced during vector-parasite interaction have the potential of being usedto modulate tsetse fly vectorial capacity.
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Biological Control, 1994
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Papers by Dr. Suliman Essuman