Rectal chlamydia--a reservoir of undiagnosed infection in men who have sex with men.

OBJECTIVE: To determine the prevalence of rectal chlamydia infection in a cohort of men who have sex with men (MSM) and the proportion of infection that would be missed without routine screening. METHODS: MSM presenting to four HIV/GUM outpatient clinics at the Chelsea & Westminster Hospital NHS Foundation Trust between 1 November 2005 and 29 September 2006 were offered testing for rectal chlamydia infection in addition to their routine screen for sexually transmitted infections (STIs). Chlamydia trachomatis (CT) tests were performed using the Beckton-Dickinson Probe-Tec Strand Displacement Assay. Positive samples were re-tested at the Sexually Transmitted Bacteria Reference Laboratory, to confirm the result and identify lymphogranuloma venereum (LGV)-associated serovars. RESULTS: A total of 3076 men were screened. We found an 8.2% prevalence of infection with CT (LGV and non-LGV serovars) in the rectum and 5.4% in the urethra. The HIV and rectal chlamydia co-infection rate was 38.1%. The majority of rectal infections (69.2%, (171/247)) were asymptomatic and would have been missed if routine screening had not been undertaken. Of the samples re-tested, 94.2% (227/242) rectal and 91.8% (79/86) urethral specimens were confirmed CT positive and 36 cases of LGV were identified. CONCLUSION: Our data show a high rate of rectal chlamydia infection, in the majority of cases it was asymptomatic. We recommend routine screening for rectal chlamydia in men at risk, as this may represent an important reservoir for the onward transmission of infection.

Lymphogranuloma venereum presenting as genital ulceration and inguinal syndrome in men who have sex with men in London, UK.

OBJECTIVES: To describe a series of lymphogranuloma venereum (LGV) cases presenting as inguinal syndrome and/or genital ulceration seen among men who have sex with men (MSM) in London, UK. METHODS: Collaborative retrospective case note review. Clinicians from three London genitourinary medicine (GUM) clinics accessed by large populations of MSM within the current LGV outbreak collected clinical data from confirmed cases of LGV inguinal syndrome or genital ulcer. LGV was confirmed by the detection of LGV-specific DNA from specimens such as bubo aspirates, ulcer swabs, urethral swabs, first void urine and rectal biopsy material. RESULTS: There were 13 cases detected overall: 5 cases of urethral LGV infection with inguinal adenopathy, 3 cases of genital ulcer with LGV inguinal adenopathy, 3 cases of isolated LGV-associated inguinal buboes, 1 case of a solitary LGV penile ulcer and 1 case with a penile ulcer and bubonulus. Only 6 of the 13 were HIV positive and all tested negative for hepatitis C. The majority of cases reported few sexual contacts in the 3 months preceding their diagnosis. CONCLUSIONS: Clinical manifestations of LGV in MSM have not been confined to proctitis in the current outbreak in the UK and a small but significant number of inguinogenital cases of LGV have been observed. Epidemiologically, many of the cases described seem to have occurred at the periphery of the current MSM LGV epidemic. Clinicians need to be vigilant for these less common presentations of LGV among MSM and specific diagnostic tests should be done from the relevant lesions.

Outpatient management of severe gonococcal ophthalmia without genital infection.

We report a case of severe gonococcal ophthalmia and peri-orbital cellulitis in an HIV-positive man without genital infection who was treated successfully in the outpatient department. We also highlight the importance of early diagnosis, treatment and liaison with ophthalmology in order to prevent visual complications.

Effect of process variables on particle size and viability of Bifidobacterium lactis Bb-12 in genipin-gelatin microspheres.

Gelatin microspheres cross-linked with genipin were developed to encapsulate the probiotic Bifidobacterium lactis Bb-12 The effects of different gelatin concentrations (10-19% w/v), bloom strengths (175 and 300), surfactants, stirring rates during emulsion formation and genipin concentrations (0-10 mM) on the microsphere sizes and viability of bacterial cells were investigated. Principal Component Analysis revealed microsphere size distribution differed depending on the presence or absence of surfactants as well as a trend of increasing micropshere size with increasing gelatin concentration and bloom strength. Lower stirring rates resulted in larger microspheres with higher encapsulation yields of bifidobacteria Microsphere size and cell viability were not significantly (p < 0.05) influenced by increasing genipin concentrations up to 10 mM whereas microsphere stability in simulated gastric juice increased with increasing genipin concentration. The encapsulation yields were higher in 175 bloom strength gelatin microspheres than in 300. Cold-stage scanning electron microscopy showed encapsulated bacteria distributed throughout the genipin cross-linked gelatin matrix.

Volatile compounds of Soumbala, a fermented African locust bean (Parkia biglobosa) food condiment.

AIMS: To determine the profile of volatile compounds responsible for the aroma of Soumbala produced spontaneously and with pure and mixed cultures of Bacillus subtilis and Bacillus pumilus. METHODS AND RESULTS: Traditional and controlled fermentation trials of African locust bean with pure and mixed starter cultures of B. subtilis (B7, B9 and B15) and B. pumilus (B10) were performed. Aroma volatiles were analysed using Likens-Nikerson method coupled with gas chromatography and mass spectrophotometry. Sensory analysis of Soumbala as well as rice dishes prepared with each type of Soumbala were carried out by 10 panellists. In total 116 compounds were identified. They included pyrazines, aldehydes, ketones, esters, alcohols, acids, alkanes, alkenes, amines, pyridines, benzenes, phenols, sulphurs, furans and other compounds. Using principal component analysis for comparison, the aroma profiles of the Soumbala samples could be separated into three groups. The sensory evaluation showed variable acceptability. However, it was noticed that Soumbala samples produced with starter cultures were scored higher than traditionally prepared Soumbala. CONCLUSIONS: Aroma volatiles and organoleptic properties of Soumbala vary according to the Bacillus isolates involved in the fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributes to the selection of Bacillus starter cultures for controlled production of Soumbala.

Effect of soybean fortification on Ghanaian fermented maize dough aroma.

The effect of soy fortification on the development of aroma compounds, dough acidity and growth of the predominant microorganisms were investigated in Ghanaian maize dough fermented spontaneously over a period of 72 h. The fortified maize dough was prepared from a milled mixture of soaked maize grains and pre-soaked, blanched and dehulled soybeans added at 20% replacement level. Extracts of volatiles from the soy-fortified and unfortified dough samples were obtained by Likens-Nickerson simultaneous distillation and extraction method analysed by gas chromatography-mass spectrometry and gas chromatography-olfactometry (gas chromatography-sniffing). Major aroma compound groups identified in the fermented dough samples were carbonyls, alcohols, esters and volatile organic acids. Twenty-nine carbonyls were found in soy-fortified maize dough compared with 21 in the unfortified dough. Although the same alcohols were found in both dough samples, the total concentration of alcohols was slightly different, being less for the soy-fortified sample. Total concentration of esters in soy-fortified dough decreased after 72 h while levels in the unfortified dough increased. Increases in the production of lactic and acetic acids occurred in soy-fortified samples, but the maximum concentrations of acetic acid achieved did not differ significantly between the two types of dough. Twenty-three compounds were perceived to be contributing to the typical aroma of soy-fortified maize dough by the method of gas chromatography-sniffing. These included 12 carbonyls, six alcohols, two esters, two acids and one furan.

Volatile compounds produced by Lactobacillus fermentum, Saccharomyces cerevisiae and Candida krusei in single starter culture fermentations of Ghanaian maize dough.

AIMS: To identify and compare the volatile compounds associated with maize dough samples prepared by spontaneous fermentation and by the use of added starter cultures in Ghana. METHODS AND RESULTS: The starter cultures examined were Lactobacillus fermentum, Saccharomyces cerevisiae and Candida krusei. For identification of aroma volatiles, extracts by the Likens-Nickerson simultaneous distillation and extraction technique were analysed by gas chromatography-mass spectrometry (GC-MS) and using a trained panel of four judges by GC-Olfactometry (GC-sniffing). Compounds identified by GC-MS in maize dough samples after 72 h of fermentation included 20 alcohols, 22 carbonyls, 11 esters, seven acids, a furan and three phenolic compounds. Of the total 64 volatile compounds, 51 were detected by GC-sniffing as contributing to the aroma of the different fermented dough samples. Spontaneously fermented maize dough was characterized by higher levels of carbonyl compounds while fermentations with added L. fermentum recorded the highest concentration of acetic acid. S. cerevisiae produced higher amounts of fusel alcohols and increasing levels of esters with fermentation time and C. krusei showed similarity to L. fermentum with lower levels of most volatiles identified. CONCLUSION: The present study has given a detailed picture of the aroma compounds in fermented maize and demonstrated that the predominant micro-organisms in fermented maize dough can be used as starter cultures to modify the aroma of fermented maize dough. SIGNIFICANCE AND IMPACT OF THE STUDY: The study has documented the advantage of using starter cultures in African traditional food processing and provided a scientific background for introducing better controlled fermentations.

Cultivar and processing effects on the pasting characteristics, tannin content and protein quality and digestibility of cowpea (Vigna unguiculata).

Four popular West African local cultivars of cowpea (Vigna unguiculata), with distinctly different seed coat colors, were evaluated for their relative amylograph pasting characteristics, condensed tannin content, in vitro protein digestibility and Tetrahymena protein efficiency ratio (t-PER). The effects of roasting and dehulling on these properties were also determined. There were wide variations in the hot paste viscosity characteristics of the different cultivars studied. The raw cowpea flour samples exhibited maximum paste viscosities ranging between 260 Brabender Units (BU) for the Mottled cultivar and 460 BU for the cream-colored Blackeye cultivar. Cowpea cultivars with the greatest peak viscosities showed low stabilities to extended cooking. Roasting depressed paste viscosity properties of all the cowpea cultivars studied. Tannin concentrations were 0.3-6.9 and 7.2-116 mg CE/g flour from whole cowpea seeds and seed coats respectively, increasing with intensity of seed color. Although dehulling removed 98% of the tannin content of raw cowpeas, improvement in protein quality as a result of dehulling was observed for only the highly-pigmented Maroon-red variety. Roasting significantly improved digestibility and more than doubled the t-PER of all cowpea cultivars studied. Roasted cowpeas possess adequate nutritional and functional qualities as protein supplements in cereal-based weaning foods. However, it appears that dehulling is necessary to enhance the nutritional quality of the highly pigmented cultivars of cowpea.

Effect of soy-fortification method on the fermentation characteristics and nutritional quality of fermented maize meal.

Studies were conducted to develop an appropriate household/small-scale enterprise level technique for the production of soy-fortified fermented maize dough (or meal) by comparing different treatments, processing methods and fortification levels. The effects of fortification method of the Ghanaian traditional fermented maize dough with raw or heat-treated whole soybeans and full-fat soyflour at 0%, 10% and 20% replacement levels, on the rate of fermentation and product quality were investigated. Sensory characteristics, trypsin inhibitor activity, amino acid pattern, proximate composition and hot paste viscosity were used as the indices of quality. Addition of whole soybeans to maize before milling and fermentation reduced the fermentation time by 60% while increasing the protein content by 24% and 70% respectively for 10% and 20% levels of fortification. A significant improvement was also achieved in the amino acids pattern of the fortified dough. However, raw whole soybeans imparted an undesirable color and beany flavor and an appreciable concentration of trypsin inhibitor activity (TIA) to the dough. Boiling soybeans for 20 min before incorporation into the maize for milling and fermentation was found necessary for desirable flavor and low levels of TIA. Little or no changes in the pasting viscosity characteristics occurred in samples containing boiled soybeans, while the usual method of fortifying maize meal with soy flour was found to severely depress the pasting viscosity characteristics and drastically reduced the acidity of the fermented dough. Based on the findings of the study, the most appropriate technique for the production of soy-fortified high protein fermented maize dough has been suggested to involve incorporation of boiled whole soybeans in soaked maize before milling and fermentation for improved sensory characteristics, enhanced nutritive value and optimal functional properties.