Evaluation of physicochemical and antioxidant properties of two stingless bee honeys: a comparison with Apis mellifera honey from Nsukka, Nigeria.

OBJECTIVE: Several physical, biochemical and antioxidant properties of two Nigerian stingless bee honey varieties (Melipona sp. and Hypotrigona sp.) were compared with Apis mellifera honey using standard analytical procedures. RESULTS: The mean pH of Apis mellifera, Hypotrigona sp. and Melipona sp. honeys were 4.24 ± 0.28, 3.75 ± 0.11 and 4.21 ± 0.37 respectively. The mean moisture contents of the honeys were 11.74 ± 0.47, 17.50 ± 0.80, and 13.86 ± 1.06%. Honey samples from Hypotrigona sp. when compared with other honey samples had the highest mean total dissolved solids (370.01 ± 22.51 ppm), hydroxymethylfurfural (16.58 ± 0.37 mg/kg), total acidity (35.57 ± 0.42 meq/kg), protein content (16.58 ± 0.37 g/kg), phenol content (527.41 ± 3.60 mg/kg), and ascorbic acid (161.69 ± 6.70 mg/kg), antioxidant equivalent-ascorbic acid assay value (342.33 ± 0.78 mg/kg) as well as ferric reducing power (666.88 ± 1.73 µM Fe(II)/100 g) (p < 0.05). Several strong correlations were observed among some of the parameters of the honeys. This is the first study to compare the properties of Nigerian honey bees. Our results suggested that these honeys (specifically Hypotrigona sp. honey) is a good source of antioxidants comparable to A. mellifera honey.

Anatomic study of the pterion in Nigerian dry human skulls.

BACKGROUND: The pterion is a point of sutural confluence seen in the norma lateralis of the skull. The site is an important landmark in surgical approaches to the anterior and middle cranial fossa. OBJECTIVE: This study was designed to determine the frequency of pterion types and anatomic positions of the pterion in dry human skulls of Nigerians in the South Eastern Zone. MATERIALS AND METHODS: Specific measurements were taken on both sides of 56 Nigerian human skulls of unknown sex, obtained from the Department of Anatomy, Nnamdi Azikiwe University, Nnewi Campus, Nnewi, Nigeria. RESULTS: All the four types of the pterion were present, i.e. sphenoparietal, frontotemporal, stellate, and epipteric. The study showed that the sphenoparietal type was 75% on the right side, 76% on the left side, the frontotemporal type was 19.6% on both sides, the stellate type was 1.8% on the right side and absent on the left side. The epipteric type was 3.6% on both sides. The distances from the centre of pterion to the frontozygomatic suture were 2.74 ± 0.07 cm on the right side and 2.74 ± 0.06 cm on the left side. The pterion was 4.02 ± 0.05 and 4.01 ± 0.03 cm above the midpoint of the zygomatic arch on the right and left sides, respectively. CONCLUSION: These findings are important for the surgeon as the pterion junction is a common extracranial landmark in neurosurgical and surgical approaches.

Patterns of superficial venous arrangement in the cubital fossa of adult Nigerians.

BACKGROUND: The cubital fossa is a common site for the removal of venous blood for analysis, transfusion, and intravenous therapy. The superficial venous return from the upper limb follows two or three major superficial veins, which are extremely variable; these include the cephalic, basilic, median cubital, and antebrachial veins and their tributaries. OBJECTIVE: This anthroposcopic study was to determine the patterns of superficial venous arrangement in the cubital fossa of adult Nigerians. MATERIALS AND METHODS: One hundred and thirty-five subjects (100 males and 35 females), aged between 20 and 27 years, were studied. The judgment sampling technique was employed. A tourniquet was firmly tied at the midarm level and the conspicuous superficial veins were diagrammatized and photographed with a camera. RESULTS: Ten types of venous pattern arranged in six groups were noted. The most common pattern observed was the median antebrachial vein, dividing into median cephalic and median basilic veins, which join the cephalic and the basilic veins, respectively, with a variation. The result showed bilateral difference between the incidence of each type in males and females with the male values being statistically higher (P < 0.05). CONCLUSION: Appreciation of these venous patterns is useful to the medical and paramedical workers, especially in conditions that require venepuncture.

Comparative virulence of Scedosporium species in animal models.

Scedosporium species are an emerging opportunist group of fungi that have been found to cause infections in both immunocompetent and non-immunocompetent individuals. The infections are not regularly distributed among different countries of the world either because of improper identification or other geographical reasons. Strange as it may, disseminated systemic infections have only been reported in some specific countries. We used a mouse model of disseminated infection to assess if strains from Nigeria were virulent and compared it to a few other strains from other countries. S. apiospermum isolated from Nigeria were clearly less virulent than those obtained elsewhere. This may be the reason why this group of fungi has not been associated with specific clinical problems in Nigeria in particular and Africa in general.

In vitro activity of conventional antifungal agents against Scedosporium apiospermum isolates recovered from clinical and environmental samples in Nigeria.

In vitro susceptibilities of Scedosporium apiospermum isolates recovered from clinical and environmental samples in Nigeria were tested against ten conventional antifungal agents, namely: amphotericin B, nystatin, flucytosine, itraconazole, posaconazole, fluconazole, voriconazole, micafungin, ketoconazole, and terbinafine using the CLSI M38-A broth dilution reference method. The isolates showed varied response/sensitivities to the antifungal agents tested. This is probably the first documented testing of Scedosporium apiospermum isolates from Africa in general and Nigeria in particular against a broad range of conventional antifungal agents.

Comparative virulence of Scedosporium species in animal models

Scedosporium species are an emerging opportunist group of fungi that have been found to cause infections in both immunocompetent and non-immunocompetent individuals. The infections are not regularly distributed among different countries of the world either because of improper identification or other geographical reasons. Strange as it may, disseminated systemic infections have only been reported in some specific countries. We used a mouse model of disseminated infection to assess if strains from Nigeria were virulent and compared it to a few other strains from other countries. S. apiospermum isolated from Nigeria were clearly less virulent than those obtained elsewhere. This may be the reason why this group of fungi has not been associated with specific clinical problems in Nigeria in pa'rticular and Africa in general.

In vitro susceptibility testing of dermatophytes isolated from pediatric cases in Nigeria against five antifungals.

The antifungal activities of itraconazole, ketoconazole, fluconazole, terbinafine and griseofulvin were tested by broth microdilution methods against 71 isolates of dermatophytes isolated from Nigerian children. Most drugs were very active against all the dermatophytes and the MIC 90 ranged from 0.03 to 8.0 microg/mL. This appears to be the first documented data on the antifungal susceptibility testing of isolates of dermatophytes from Nigerian children.

In vitro susceptibility testing of dermatophytes isolated from pediatric cases in Nigeria against five antifungals

The antifungal activities of itraconazole, ketoconazole, fluconazole, terbinafine and griseofulvin were tested by broth microdilution methods against 71 isolates of dermatophytes isolated from Nigerian children. Most drugs were very active against all the dermatophytes and the MIC 90 ranged from 0.03 to 8.0 µg/mL. This appears to be the first documented data on the antifungal susceptibility testing of isolates of dermatophytes from Nigerian children.

Atividades antifúngicas de itraconazole, ketoconazole, fluconazole, terbinafine e griseofulvina foram testadas por métodos de microdiluição em caldo contra 71 isolados de dermatófitos de crianças nigerianas. A maioria das drogas foi muito ativa contra todos os dermatófitos e o MIC 90 variou de 0,03 a 8,0 µg/mL. Estes parecem ser os primeiros dados documentados sobre os testes de susceptibilidade antifúngica de isolados de dermatófitos de crianças nigerianas.

Prevalence of dermatophytic fungal infections in children: a recent study in Anambra state, Nigeria.

We conducted a recent survey of dermatological fungal infections amongst children in both urban and rural parts of Anambra State in the south-east geographical flank of Nigeria during the period January 2003 to December 2003. Samples were collected from 1624 children with clinically suggestive lesions and also between the ages of 4 and 16. Young children aged 7-11 and 4- 6 years had significantly higher incidences (P < 0.05) than their older colleagues aged 12-16 years among samples proved to be mycologically positive by microscopy, culture or both. There was a significant difference in the incidence of dermatophytoses amongst children in urban and rural areas investigated (P < 0.05). Tinea capitis was the predominant clinical type. Trichophyton tonsurans was the most prevalent etiological agent while Microsporum audouinii was the least in occurrence. We compared our result with a recent study in the northern geographical zone and observed that although incidence of dermatophytoses is higher in northern Nigeria, tinea capitis was the predominant clinical type in both regions. In addition, the etiological agents appear to vary from time to time in their occurrence and the reasons for these observations are discussed. A regular surveillance and assessment of the etiologic agent and its prevalence by medical mycologists is strongly recommended to facilitate monitoring, reduce/prevent transmission and spread of dermatophytes in countries like Nigeria where they constitute a public health problem.

Keratinolytic activity of five human isolates of the dermatophytes.

The keratinolytic activity of five species of the dermatophytes which include Trichophyton rubrum, T. mentagrophytes, T. tonsurans, Microsporum audouinii and M. gypseum isolated from school children were tested using human hair as the substrate. M. gypseum was found to possess the highest keratinolytic activity with a net value of released protein being 78.8 ug/ml after five weeks of incubation. Also the net value of released protein for T. tonsurans, T. rubrum, T. mentagrophytes and M. audouinii were 55.5 ug/ml, 52.5 ug/ml, 43.8 ug/ml and 26.3 ug/\ml respectively. Only T. mentagrophytes and M. gypseum were able to cause structural damage in form of perforations on the hair shaft. Also during the degradation of the hair, the pH of the basal medium for each dermatophyte increased. The increase in pH was highest in the medium with M. gypseum but lowest in that of M. audouinii.

In vitro effects of three metallic salts and soot on the growth of five species of the dermatophytes.

The antifungal effects of zinc chloride (znCl), Calcium chloride (CaCl), magnesium chloride (MgCl) as well as soot collected from a local kitchens were tested on five isolated species of the dermatophytes from cases of human dermatophytoses. Of these three metallic salts, ZnCl showed the highest inhibitory effect on the dermatophytes. At a concentration of 0.01 M it showed 100% inhibition on these fungi. Although the other two metallic salts showed some inhibitory effect CaCl at concentration between 0.01 M and 1 M showed only 50% inhibitory effect while MgCl at concentration between 0.1 M and 1 M showed less than 50% inhibitory effect on the fungi. Also soot inhibited the growth of all the dermatophytes tested at concentration between 0.1 and 2%. Trichophyton rubrum and Microspum audouinii appeared to be most sensitive to these compounds compared to the other three species which include T. mentagrophytes, T. tonsurans and M. gypseum.

Dermatophytoses among school children in Aba, Abia State--Nigeria and some physiological studies on the isolated etiologic agents.

A total of 1,136 school children comprising 433 males and 703 females, within the age groups 4 to 16 years and all resident in Aba municipal town of Abia State were examined for clinical signs of dermatophytoses. Out of this number examined 196 (17.3%), which included 108 males and 88 females, had clinical lesions on various parts of the body including the head, skin, finger nails and toe webs characteristic of dermatophytoses. While the infection occurred highest among children between the ages of 10 and 12 years, male children were significantly more infected than the females (P = 0.05). The most common type of the disease was tinea capitis (10.8%) followed by tinea corporis (5.8%). The dermatophytes identified included Trichophyton mentagrophytes (19.4%). T. tonsurans (12.3%), Microsporum audoninii (7.7%) and M. gypseum (2%). All the isolates grew well at both 25 degrees C and 37 degrees C but none survived at 45 degrees C. On solid media, all, with the exception of M. gypseum produced extracellular lipase enzyme while none produced lecithinase, deoxyribounclease and protease enzymes. Only T. tonsurans and T. mentagrophytes produced urease enzyme.

Some pathogenic fungi involved in serious cases of urinary tract infections in Nigeria.

Three hundred early morning midstream urine samples collected from 200 females and 100 males between the ages of 20 and 60 years, suffering from urinary tract infections (UTI) were studied to determine the etiologic agents. The caliberated loop-direct method used for culturing each sample on both bacterial and fungal media showed significant microbial growth in 117 of the 300 samples. Bacteria were the sole agents of infection in 30% of the cases while pathogenic yeasts were the sole agents of infection in 8% of the cases. Only 1% showed mixed infection. The bacterial pathogens identified from the culture were Escherichia coli (12.7%), Staphylococcus aureus (8.0%), Proteus mirabilis (4.3%), Klebsiella aerogenes (2.7%), Streptococcus faecalis (2.0%) and Pseudomonas aeruginosa (0.3%). The fungal pathogens isolated were Candida albicans (0.3%). While patients between the ages of 20 and 40 years were significantly more susceptible to UTI caused by bacteria (P = 0.05), patients between the ages of 41 and 60 years were more prone to UTI caused by fungi. Also females appeared to contact UTI more often than males.

Prevalence of Cryptosporidium oocysts in faecal samples of some school children in Enugu State, Nigeria.

A total of 373 stool samples comprising 38 watery stool and 335 normal formed samples, collected from primary school children in Enugu State, Nigeria, were processed for the presence of Cryptosporidium oocysts. The formalin-methylene blue staining techniques were employed for the concentration and identification of the Oocysts in each sample. The results obtained were subjected to cross-tabulation analysis. Cryptosporidium Oocysts were identified in 15 of the 38 watery stool samples and in 81 of the 335 formed stool samples. Analysis of the data obtained showed that there was no significant difference in carrier rate of the parasite between school children from the urban town of Nsukka and those from the rural towns of Ovoko and Obukpa (P = 0.441). However, the rate of occurrence of the Oocysts was significantly higher in the watery stool than in the formed stool samples (P = < 0.0001).

Preliminary studies of the antifungal activities of some medicinal plants against Basidiobolus and some other pathogenic fungi.

The antifungal activities of extracts of 10 medicinal plants collected from south-eastern parts of Nigeria were tested against seven pathogenic fungi using the broth dilution and agar plate methods. All the extracts at 1:10 dilution inhibited the growth of Basidiobolus haptosporus and B. ranarum but did not inhibit that of Aspergillus fumigatus, Geotrichum candidum and Candida albicans. While extracts from Piper guineense, Ocimum gratissimum, Moringa oleifera and Erythrophleum suaveolens inhibited the growth of Trichophyton rubrum and T. mentagrophytes, those from Fatropha curcas, Mitracarpus villosus, Azadirachta indica and Gongronema latifolium failed to do so at 1:10 dilution. Extract from Piper sp. was also able to inhibit the growth of B. haptosporus at a concentration as low as 1:80 dilution followed by those of Ocimum and Rauvolfia spp. at 1:40 dilution. These results indicate possible use of certain plant extracts in the treatment of subcutaneous phycomycosis in humans and animals.

Purification and characterization of protease enzymes of Basidiobolus and Conidiobolus species.

The protease enzymes produced by one strain of each of Basidiobolus haptosporus, B. ranarum and Conidiobolus coronatus were purified by precipitation and Sephadex G-100 gel filtration chromatography. The enzymes prepared were characterized in terms of their specific activities and temperature and pH optima as well as their molecular weights. All three fungi produced one protease of 23,000 Da molecular weight. Conidiobolus coronatus additionally secreted a second protease of 32,000 Da molecular weight.

Cryptosporidiosis in patients with diarrhoea in five hospitals in Nigeria.

A total of 413 soft, loose or watery stool specimens from patients with acute diarrhoea were screened for presence of Cryptosporidium oocysts. Safranin-methylene blue staining technique was used for detecting Cryptosporidium oocysts in the stool samples. The oocysts were identified in 52 (12.5 per cent) of the samples, while 69 samples (16.7 per cent) showed mixed infections. Children between the ages of 2 and 15 years were most infected by this parasite while infection occurred more in females than males for all age groups. These findings indicate that Cryptosporidium is an important etiologic agent of diarrhoea. Hence there is need to include its identification in laboratory analysis of diarrhoeal stool samples.

Lipase activity of Basidiobolus and Conidiobolus species.

Two isolates of Basidiobolus namely, B. haptosporus (ATCC 36600) and B. ranarum (MHB1), and one isolate of Conidiobolus coronatus (C1) were grown in modified Sierra medium for twelve days. Periodic measurements of their lipase activity showed significant activity of the enzyme from the fourth day with a steady increase up to the twelfth day of incubation. The lipases produced by the three isolates were stable over a wide range of pH (4-8) and temperature (30-60 degrees C). Maximum lipase activity for B. haptosporus and C. coronatus was at pH 5.0 and that for B. ranarum was at pH 6.0. The three fungi exhibited a peak of activity at the same temperature, i.e. 35 degrees C.

Comparative antigenic studies of species of Basidiobolus and other medically important fungi.

An immunodiffusion technique was used to evaluate the antigenic relationship of various pathogenic and saprobic Basidiobolus spp., Conidiobolus spp., isolates of the order Mucorales, and several other medically important nonzygomycetous fungi. The antiserum to Basidiobolus haptosporus shared two lines of identity, designated inner (N) and outer (Y), when tested against exoantigens of known strains of B. haptosporus and Basidiobolus ranarum as well as exoantigens of a human Nigerian isolate and several wild isolates tentatively identified in B. ranarum. Both bands were heat stable at 56 degrees C for 30 min. Exoantigens of strains of Basidiobolus meristosporus, Basidiobolus microsporus, Conidiobolus incongruus, Conidiobolus coronatus, and other wild isolates of Basidiobolus spp. tested formed only the N immunoprecipitin band. Exoantigens of 10 isolates from other taxa did not produce any cross-reactive precipitin line. B. meristosporus antiserum that was tested against exoantigens of Basidiobolus spp. and of Conidiobolus spp. developed only an N band without a Y band. These data suggest that B. haptosporus and B. ranarum are antigenically similar to each other and distinct from B. meristosporus. Basidiobolus spp. and Conidiobolus spp. share a common N immunoprecipitin band, which implies a taxonomic relationship between these two genera. The absence of lines of identity between Basidiobolus spp. and other fungi tested suggests that, antigenically, Basidiobolus is a distinct genus.