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PCR Detection of Entamoeba histolytica in Microscopically Positive Stool Samples of Hospital Patients in Soroti, Eastern Uganda

J Ekou, JI Nakavuma, J Erume, M Ocaido

 

Abstract

Amoebiasis is an infection caused by water borne protozoan parasite Entamoeba histolytica. In Uganda where sanitation infrastructure and health education was not adequate, amoebiasis was thought to be still an important health problem. However there was little or no data on prevalence of this very important protozoan infection. In addition, microscopy remained the main method for the diagnosis of amoebiasis but could not differentiate between Entamoeba dispar/moshkovskii and Entamoeba histolytica infections. This made determination of true prevalence of Entamoeba histolytica infections difficult. It was against this background that this study was designed to carry out species specific diagnosis of Entamoeba histolytica and Entamoeba dispar/moshkovskii in Uganda where these species had been reported to be endemic. This study used microscopy and polymerase chain reaction amplification of Serine-rich Entamoeba histolytica (SREHP) gene. It was shown that 36.7% (n=22) of the samples initially diagnosed as positive by microscopy were positive by PCR. The true prevalence of E. histolytica and E.dispar/ moshkovskii was found to be 7.31% and 12.6% respectively. It was concluded that Entamoeba infection in Soroti, Eastern Uganda is more frequently due to E. dispar /moshkovskii (13.3%) the non-pathogenic forms than to E. histolytica, the pathogen (7.31%).

Key words: Entamoeba histolytica, Microscopy, Polymerase chain reaction, Prevalence.

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PCR Detection of Entamoeba histolytica in Microscopically Positive Stool Samples of Hospital Patients in Soroti, Eastern Uganda

 

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Molecular Identification of Methicillin-Resistant Staphylococcus aureus in Benin-City Nigeria

O Obasuyi

 

Abstract

We use the molecular techniques of PCR and PFGE to identify MRSA from clinical isolates of Staphylococcus aureus causing infections among hospitalized patients in Benin-City, Nigeria. A total of 36 isolates were obtained from the University of Benin Teaching Hospital between July-September, 2007. The MRSA strains were selected according to their phenotypic characteristics (antibiotic resistant profiles), susceptibility to oxacillin by E-test, and detection of β-lactamase. This was verified by a latex agglutination test for PBP2a production combined with PCR for mecA gene carriage. Four isolates representing 11% were confirmed as MRSA according to the molecular techniques used with two PFGE types (H and L) and one agr type (1). Multi resistance to the various antibiotics used was observed in one of the clones. The isolation of MRSA in health institution indicates that adequate steps in limiting spread are urgently needed. Also, for the first time two MRSA clones according to the PFGE classifications have been identified in Nigeria.

Keywords: methicillin-resistant Staphylococcus aureus, MRSA, PFGE, PCR, molecular techniques.

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Molecular Identification of Methicillin-Resistant Staphylococcus aureus in Benin-City Nigeria

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INCIDENCE OF DERMATOPHYTE INFECTIONS AMONGST SOME OCCUPATIONAL AND SELECT GROUPS IN JOS

P.O. Nwadiaro

 

Abstract

Fifty-nine Agro farm workers, 265 inmates from Jos main prison, 60 hair weavers and 40 car washers were examined in Jos for dermatophyte infections. Dermatophyte isolates included Trichophyton and Microsporum species. The highest infection rate of 75% was recorded among the farm workers with toeweb infections due to T. mentagrophytes and M. canis. 25% of the other infections were from the groin region due to T. tonsurans and T. mentagrophytes. Fifty-nine percent of infection by T. mentagrophytes in prison inmates was restricted to the groin region. Other species of fungi isolated from the inmates were Trichosporon cutaneum and Aspergillus niger. Among the car washers, tinea manum, ringworm of the hand, and interdigital infections due to T.mentagrophytes were observed. There was no visible infection among either the female hair weavers or the female prison inmates.

Keywords: Dermatophytosis, T. mentagrophytes, T. tonsurans, M. canis, Tinea pedis, Tinea cruris.

(Af J Clinical & Exp Microbiology: 2003 4(2): 11-17)

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INHIBITION OF SWARMING BY UREA AND ITS DIAGNOSTIC IMPLICATIONS AMONG UROPATHOGENIC PROTEUS SPECIES FROM LAGOS, NIGERIA

B.A. Iwalokun, K.A. Akinsinde, N. Nkiruika

 

Abstract

The anti-swarming property of urea and effects on antibiotic susceptibility among 52 uropathogenic Proteus strains from Lagos, Nigeria were investigated. Urea caused a reduction in swarming and number of swarmed cells at 0.5% (n = 42, DOCZ = 15.5mm), 0.75% (n= 24, DOCZ = 10.7mm), 1% (n = 17, DOCZ = 3.4mm) and 1.25% (n = 8, DOCZ = 1.7mm).  Compared to DOCZ obtained at 0.5% urea, the further reduction in DOCZ at other urea concentrations was found to be significant (p < 0.05).  Urea at less than 0.75% allowed identification of E. coli, K. pneumoniae and S. saprophyticus in mixed cultures containing Proteus spp, while colonies of Pseudomonas aeruginosa were distinctly identified at 1% urea with swarming restrained at 1.25% urea.  At 1.25% urea, antibiotic susceptibility testing by agar diffusion method revealed significant increase and decrease in the number of Proteus strains that showed resistance to amoxicillin and nitrofurantoin. Compared with the control, significant increases in the MICs of gentamicin or nitrofurantoin and streptomycin were found at $ 0.5% and $ 0.75% urea respectively (p<0.05). The identification of extended spectrum beta lactamases (ESBL) producing strains were unaffected by urea.  This study has demonstrated urea induced swarming inhibition of uropathogenic Proteus in vitro.  However, results suggest the use of urea with great caution in diagnostic practices for optimal clinical and public health benefits in Nigeria.

Keywords: Antibiotic susceptibility, anti-swarming, urea, uropathogenic proteus, Nigeria, DOCZ = Diameter of outermost colony zone mean value

(Af J Clinical & Exp Microbiology: 2003 4(2): 18-28)

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THE EFFECT OF SOME NIGERIAN LOCAL HERBS ON HELICOBACTER PYLORI

S. I. Smith, K.S. Oyedeji, B. Opere, B. A. Iwalokun, E. A. Omonigbehin

 

Abstract

Four Nigerian medicinal plants commonly used in the treatment of bacterial infections were tested for antimicrobial activity against twenty local strains of Helicobacter pylori recovered from patients with gastro-duodenal ulcers and gastritis. In vitro agar diffusion assay revealed anti-Helicobacter pylori activity of ethanolic extracts of C. papaya and M. lucida to 80% (16/20) of the isolates tested, while the ethanolic extracts of O. gratissimum and P. amarus inhibited the colonial growth of 35% (7/20) of these strains. The zones of inhibition ranged from 5 – 20 mm in diameter. Contrastingly, the aqueous extracts of these plants appeared to lack anti-Helicobacter pylori activity except in M. lucida and O. gratissimum where inhibition of a total of three isolates was observed. The present results suggest the presence of anti-Helicobacter pylori principles in ethanolic extracts of C. papaya and M. lucida and support their future use in the treatment of ulcers and gastritis in Nigeria.

(Af J Clinical & Exp Microbiology: 2003 4(2): 29-35)

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BACTERIOLOGICAL QUALITY OF SOBO DRINKS RETAILED WITHIN ILORIN METROPOLIS

A. O. Olowe, K.I.T. Eniola, A.O. Adeyeba, S. Awe

 

Abstract

Sobo drinks retailed within Ilorin metropolis were investigated for their bacteriological quality, in terms of the total bacterial count and types of bacterial species present. The sobo drinks were found to have an average pH of 3.2. The bacterial counts were generally high ranging from 5.0×104 to 24×104 CFU/ml. Six bacterial species; Bacillus subtilis, Staphylococcus aureus, Streptococcus faecalis, Klebsiella spp, Enterobacter spp, and Escherichia coli were isolated. Consideration of the distribution pattern showed that samples from Unilorin Main Campus and General Post Office contained all the isolates, while three of the isolates; Escherichia coli, Bacillus subtilis and Staphylococcus aureus were common to all samples. Possible sources of the contaminants and their public health implications are discussed and suggestions offered on ways of ensuring safety of the sobo drinks.

(Af J Clinical & Exp Microbiology: 2003 4(2): 36-40)

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BACTERIOLOGICAL EXAMINATION OF CHRONIC OSTEOMYELITIS CASES IN ILE-IFE, SOUTHWESTERN NIGERIA

A.K. Ako-Nai, I.C. Ikem, A. Aziba, A.A. Ajayi, O.A. Onipede

 

Abstract

The bacteriological examination of chronic osteomyelitis cases in Ile-Ife, revealed Proteus mirabilis as the predominant isolate encountered (23.1%). Staphylococci constituted 30.7% of the total bacterial isolates with Staphylococcus aureus accounting for only 10.2%. Other Gram-positive cocci cultured include, Staphylococcus spp (20.5%), coagulase negative staphylococci (CONS) (12.8%) and Streptococcus spp (1.2%). Gram-negative rods constituted 55.1% of the total isolates with Pseudomonas aeruginosa being 8.5%, Escherichia coli 5.1%, Citrobacter freundii and Salmonella spp 2.5% each. Antibiotic sensitivity test revealed all isolates to be multi-resistant to traditional antimicrobials, which is of epidemiologcal importance in treating cases of chronic osteomyelitis in this environment. The study suggests institution of aggressive therapeutic interventions to avert possible sequalae.

(Af J Clinical & Exp Microbiology: 2003 4(2): 41-51)

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STUDIES ON DIABETIC FOOT ULCERS IN PATIENTS AT JOS UNIVERSITY TEACHING HOSPITAL, NIGERIA

E.I. Ikeh, F. Peupet, C. Nwadiaro

 

Abstract

An epidemiologcal and microbiological studies of diabetic foot ulcers were carried out in our hospital, with a view to reducing the amputation and mortality rate associated with the disease. Wound swabs from 38 Diabetes Mellitus (DM) foot ulcer patients were investigated using culture methods for both strict aerobes and anaerobes. The bacterial isolates were subjected to antibiotic susceptibility tests using the disc diffusion method. Baseline biochemical and haematological analysis were also carried out. The prevalence of the disease was stratified in relation to some clinical and laboratory parameters, gender, age, educational and occupational status of the patients. The prevalence of the disease was 24.7%, with amputation and mortality rates of 18.4% and 15.8% respectively. Only 13% had DM for less than 1 year, while 53% for more than 10 years. 28.9% have regular shoe-wearing habits. Duration of healing ranged from 2 weeks to 24 weeks (mean = 2.7months). 31% of the patients with marked periosteal reaction had lower extremity amputation or died before amputation could be done. Staphylococus aureus (31%), Proteus spp (16%), Pseudomonas aeruginosa (10%), Klebsiella spp (6%), Peptococcus spp (6%), Bacteroides fragilis (3%), Streptococcus pyogenes (3%), Escherichia coli (3%), Candida albicans (3%), Streptococcus viridans (1%), Flavobacterium spp (1.5%) and Bacteroides melaninogenicus (1%) were isolated. Most of the bacteria isolates were sensitive to pefloxacin. Our results demonstrate a very high rate of diabetic foot ulcer with the corresponding high rate of amputation and mortality. A multi-disciplinary approach to the management of DM foot ulcers is advocated. Efforts should be made to carry out cultures of samples from refractory ulcers to rule out yeast colonization, which if not treated will delay wound healing.

Key words: Diabetic foot ulcers, Microbial and antimicrobial surveillance, Refractory ulcers.

(Af J Clinical & Exp Microbiology: 2003 4(2): 52-61)

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AETIOLOGIC AGENTS OF DIARRHOEA IN CHILDREN UNDER FIVE YEARS OF AGE IN OSOGBO, OSUN STATE

O.A. Olowe, A.B. Olayemi, K.I.T. Eniola, O.A. Adeyeba

 

Abstract

A survey of the aetiological agents of diarrhoea in children under 5 years of age was carried out in Osogbo, Osun State. A total of 135 patients visiting the outpatient and children emergency units of LAUTECH Teaching Hospital were examined. Strains of Shigella isolated were tested for antibiotic sensitivity. Consideration of the distribution showed that Escherichia coli was more prevalent in children aged between 3 to 5 years (57%) and was the most encountered of the organisms isolated (present in 77.8% of all samples) while Shigella spp was found in 16.3% of samples, Vibrio cholerae 0.7% and other coliforms 5.2%. Statistical analysis showed that E. coli was significantly associated with diarrhoea in the patients aged 3-5 years (P< 0.05). Shigella spp was shown to show some resistance to tetracycline and high sensitivity to ofloxacin.

(Af J Clinical & Exp Microbiology: 2003 4(2): 62-66)

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PHAGE AMPLIFICATION TECHNOLOGY AND ANTI-TUBERCULOUS DRUG SUSCEPTIBILITY TESTING IN NIGERIA

E.J. Otive-Igbuzor

 

Abstract

The emergence of multi-drug resistant tuberculosis (MDR-TB) defined as combined resistance to the two most effective anti-tuberculosis drugs, rifampicin and isoniazid, threatens to create a public health hazard of unprecedented proportion. The fact that MDR-TR is more difficult and expensive to cure creates the need for prompt diagnosis. Conventionally, the proportion method on Lowenstein Jensen (L J) medium is used in most developing countries as the ‘gold standard’ in the drug susceptibility testing of Mycobacterium tuberculosis (MTB) and it takes 3-4 weeks to give results from an MTB culture. The use of phage as a diagnostic is fast gaining ground today. It involves targeting viable MTB cells from culture with a specific mycobacteriophage. After a one-hour incubation, it is treated with an antivirus to destroy the phages that are not protected with the bacilli. Upon addition of cells of growing, non-pathogenic Mycobacterium smegmatis (sensor cells), progeny phage from the MTB cells infect the sensor cells, thus amplifying the effect of the phage. When plated in an agar medium overnight, plaques occur in the cell lawn indicating the presence of viable MTB in an original sample. A comparison is made between the number of plaques produced in a drug-free control and a sample incubated in the presence of the drug. While the presence of plaques beyond a cut-of point indicates drug resistance, the absence of plaques indicates that the drug destroyed MTB cells. Overall accuracy from several trials so far conducted is put at 97-98% compared with the ‘gold standard’. With the phage amplification method, antituberculosis drug susceptibility results are obtained from MTB culture within 48 hours as opposed to the L J proportion method, which gives resulted in 3 to 4 weeks. Also, phage, as a diagnostic, is much more applicable in Nigeria laboratories than newer, rapid methods which requires specially dedicated instrumentation and are therefore very expensive. Phage amplification technology requires no special equipment and the results can be read visually.

Key words: Tuberculosis, drug susceptibility, phage, treatment, FASTPlaque-TB, rifampicin

(Af J Clinical & Exp Microbiology: 2003 4(2): 67-78)