Isolation and Characterization of Antichloramphenicol Antibodies using SDS Page

Background: Antichloramphenicol antibodies can be produced in small or large animals depending on the requirement of the researcher. Previously most researchers have raised antibodies in small animals such as rabbits due to their easy availability and handling. In the present study antichloramphenicol antibodies were produced in large animals because large volumes of serum was needed for various studies. Objective: The objective of the present study was to isolate and characterize antichloramphenicol antibodies produced in camels, donkeys and goats for development of a CAP Enzyme Linked Immunosorbent Assay. Methods: The methods employed were SDS-PAGE electrophoresis which involved the analysis of crude and purified goat, camel and donkey antichloramphenicol antibodies. Purification of the antichloramphenicol antibodies was carried out by precipitation using ammonium sulphate. Immunization of experimental animals was carried out using standard immunological methods. Results: The results indicated that the crude anti-CAP antibody produced in camels, goats and donkeys showed 7 protein bands of molecular sizes 11.7, 40, 61.6, 134.3, 145, 169.5 and 182 kda. However the protein band of molecular weight 11.7 kda was not observed in the purified antibody from the 3 animal species.  The protein bands of the camel appeared smaller and were more distinct as compared to those of donkeys and goats. Conclusion: From this study it was concluded that purified camel antibodies are smaller and more specific followed closely by goat antibodies and donkey antibodies. Keywords: anti-chloramphenicol (CAP) antibodies, camels, goats and donkey

Detection of Leishmania Antigen from Buccal Swabs in Kala-azar Patients Using KATEX Method

Background: Visceral leishmaniasis (VL) or kala-azar is a chronic protozoan infection in humans that is fatal unless treated and is associated with significant global morbidity and mortality. Confirmation of visceral leishmaniasis (VL) diagnosis requires microscopic examination to visualize the causative agent Leishmania Donovani usually in spleen or bone marrow aspirate. Tissue aspiration is invasive, potentially risky and require skilled personnel. KATEX (Kalon biologicals) antigen test for VL in buccal swabs has not been evaluated locally and could offer a significant advantage in screening patients suspected of VL.  Method: A cross sectional study was conducted after receiving approval from KEMRI SERU. We obtained buccal swabs from patients presenting at Kimalel Health Centre, Baringo County, Kenya from VL cases and controls. VL was defined as patients meeting VL case definition with positive splenic aspirate microscopy while endemic controls were defined as patients presenting to the health center with no fever and no prior history of Kala azar but living in VL endemic. Latex agglutination based test (KATEX) was used to detect parasite antigen in buccal swabs. It was a proof of principle study carried out to explore the ability to use KATEX, a simple non-invasive diagnostic test to detect leishmania antigens in buccal swabs, determine the ability of the kit to detect leishmania antigens in buccal cells of kala-azar patients and compare the sensitivity and specificity of KATEX - buccal assay using microscopy as the gold standard. Results: 88 patients were analyzed, including 44 VL and 44 non-VL patients. The median age of VL patients was 18 years with predominance of males (68.2%). None of the tested VL patients were co-infected with HIV. KATEX kit was able to detect visceral leishmaniasis antigens from the buccal swabs giving a sensitivity of (81.8%; 95%CI: 67.3% to 91.8%, specificity of (79.5%; 95%CI: 64.7 –90.2%), Positive predictive value n= 36(80.0%); 95%CI: 65.4% to 90.4% and Negative predictive values n = 35(81.4%); 95% CI: 66.6% to 91.6%. Conclusion and Recommendation: Buccal swab test assay using KATEX is an easy test to perform and promising non-invasive based antigen detection test which may be useful for screening kala-azar patients and could be applied in the diagnosis of VL. It is a functional assay that warrants a larger study with a larger sample size for the purpose of evaluating the utility of the test in diagnosing visceral leishmaniasis. There is dire need to identify non-invasive, less risky and field adapted point of care diagnostics for VL. Keywords: Kala-azar; Visceral Leishmaniasis; Diagnosis; KATEX; Latex; Buccal swab antigen detection

Potential Animal Sources of Antibodies for the Development of a Chloramphenicol Enzyme-Linked Immunosorbent Assay

Background: Chloramphenicol (CAP) is a cheap and effective broad-spectrum antibiotic that has been used in veterinary practice to treat septicaemia, pulmonary, urinary and digestive tract infections. However it has been found to be toxic to humans and may lead to an irreversible aplastic anaemia. Due to these side effects CAP was banned from use in food-producing animals. Objective: The objective of the present study was to produce and select a suitable anti CAP antibody from camels, donkeys or goats for development of a CAP Enzyme Linked Immunosorbent Assay. Method: The methods employed were immunological for immunization of experimental animals and conjugation for preparation of CAP- HRP (Horseradish Peroxidase) conjugate. Ammonium sulphate was used for purification of the antibodies. Results: Antibody production improved with subsequent boosters in camels whereas in donkeys initial immunization yielded significantly (P<0.05) higher titres of anti-CAP antibodies. The anti-chloramphenicol antibody produced in camels following the 11th booster (797 days after immunization) was found to be more specific and sensitive than that produced in donkeys and goats. Conclusion: From this study it was concluded that anti-CAP antibodies from camels were more suitable for the development of a chloramphenicol ELISA. Key words: anti-chloramphenicol antibodies, camels, goats, donkey

Assessment of hepatitis B vaccination status and hepatitis B surface antibody titres among health care workers in selected public health hospitals in Kenya.

Healthcare workers (HCWs) have a significant occupational risk of hepatitis B virus (HBV) infection. Vaccination remains the most effective measure recommended to avert the risk. However, there's limited information on hepatitis B vaccine uptake rates and the seroprotection status of HCWs, especially in sub-Saharan Africa. This study aimed to assess hepatitis B vaccination status and also seroprotection status of HCWs in three selected public hospitals in Kenya. This was a cross-sectional study carried out among HCWs at Kenyatta National Hospital (KNH), Naivasha and Mbagathi County hospitals. Data on participants' demographics and hepatitis B vaccination status was collected using an interviewer-guided questionnaire. Blood samples were collected and tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibodies (anti-HBs), and hepatitis B core antibodies (anti-HBc) using Enzyme Linked Immuno Sorbent Assay technique. Data were analyzed using Statistical Package for the Social Sciences (SPSS) and Graph pad prism. Of the 145 eligible HCWs, 120 (82.8%) were vaccinated, with 77 (53.1%) having received the recommended three doses. Three quarters (108/145) of the vaccinated HCWs were seroprotected (titres ≥10 mIU/ml) against HBV infection, while 16.6% were non-responders (titres <10 mIU/ml). Vaccination with more than two doses and HBV exposure were significantly associated with anti-HBs titre levels (P<0.05). HCWs who received less than 2 doses of the vaccine were 70% less likely to have high anti-HBs titre levels (aOR, 0.3; 95% CI, 0.1-0.8; P = 0.013). Nearly all HCWs were vaccinated against hepatitis B virus. The majority of all HCWs were seroprotected against hepatitis B virus but a number of them had an insufficient immunity to the virus despite vaccination or prior exposure. There's need to sensitize HCWs and enforce mandatory full vaccination as per the recommended vaccination schedule

Interviewer-guided questionnaire.

Healthcare workers (HCWs) have a significant occupational risk of hepatitis B virus (HBV) infection. Vaccination remains the most effective measure recommended to avert the risk. However, there’s limited information on hepatitis B vaccine uptake rates and the seroprotection status of HCWs, especially in sub-Saharan Africa. This study aimed to assess hepatitis B vaccination status and also seroprotection status of HCWs in three selected public hospitals in Kenya. This was a cross-sectional study carried out among HCWs at Kenyatta National Hospital (KNH), Naivasha and Mbagathi County hospitals. Data on participants’ demographics and hepatitis B vaccination status was collected using an interviewer-guided questionnaire. Blood samples were collected and tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibodies (anti–HBs), and hepatitis B core antibodies (anti–HBc) using Enzyme Linked Immuno Sorbent Assay technique. Data were analyzed using Statistical Package for the Social Sciences (SPSS) and Graph pad prism. Of the 145 eligible HCWs, 120 (82.8%) were vaccinated, with 77 (53.1%) having received the recommended three doses. Three quarters (108/145) of the vaccinated HCWs were seroprotected (titres ≥10 mIU/ml) against HBV infection, while 16.6% were non–responders (titres PP = 0.013). Nearly all HCWs were vaccinated against hepatitis B virus. The majority of all HCWs were seroprotected against hepatitis B virus but a number of them had an insufficient immunity to the virus despite vaccination or prior exposure. There’s need to sensitize HCWs and enforce mandatory full vaccination as per the recommended vaccination schedule.</div

Demographic characteristics and hepatitis B vaccination status of participating HCW at KNH, Mbagathi County and Naivasha sub-county hospitals (N = 145).

Demographic characteristics and hepatitis B vaccination status of participating HCW at KNH, Mbagathi County and Naivasha sub-county hospitals (N = 145).</p

Classification of immune responses based on anti-HBs titres, vaccination and HBV exposure status among HCW at KNH, Mbagathi County and Naivasha sub-county hospitals.

Classification of immune responses based on anti-HBs titres, vaccination and HBV exposure status among HCW at KNH, Mbagathi County and Naivasha sub-county hospitals.</p

Anti–HBs response based on vaccination and HBV exposure status among HCW at KNH, Mbagathi County and Naivasha sub-county hospitals.

Anti–HBs response based on vaccination and HBV exposure status among HCW at KNH, Mbagathi County and Naivasha sub-county hospitals.</p

Odds ratio for covariates that impact anti-HBs production among HCW.

ORs and 95% CI with significant associations indicated at P<0.05 Abbreviations: OR, odds ratio; cOR, crude odds ratio; aOR, adjusted odds ratio; CI, confidence interval.</p