Cardiovascular MR imaging in cardio-oncology.

Patients with cancer are subject to short-term and long-term adverse cardiovascular outcomes from cancer therapies. It is important to identify patients at risk for cardiotoxicity so that appropriate therapy can be instituted early. Cardiovascular magnetic resonance (MR) imaging is emerging as a promising imaging modality with unique applications beyond standard left-ventricular systolic function assessment. It can provide comprehensive evaluation of most cardiac structures in one setting. This article provides an overview of cardiac MR imaging in cardio-oncology.

Cloning and expression of streptomycin inactivating enzymes APH(6)-Ia and APH(6)-Id.

Discovered in the 1940s by Selman Waksman, the aminoglycoside antibiotic streptomycin is clinically important in the treatment of tuberculosis worldwide. However, strains of Mycobacterium tuberculosis and other pathogenic bacteria have become resistant to streptomycin. One mechanism by which this can occur is through the action of phosphotransferases that attach a phosphate group to position 6 of the streptidine ring of streptomycin, thereby inactivating it. Two such phosphotransferases are APH(6)-Ia from producer strain Streptomyces griseus, and APH(6)-Id found in animal, plant and human pathogenic isolates. Here, we report the subcloning and expression in Escherichia coli of soluble recombinant APH(6)-Ia and Id enzymes. Sequencing of aph(6)-Ia revealed a one-nucleotide disagreement with the published sequence, such that the amino acid at position 262 is an alanine instead of a serine. The sequence of aph(6)-Id is identical to that of the gene found in transposon Tn5393 of plant pathogen Erwinia amylovora. The successful expression of soluble forms of these enzymes now paves the way for experiments to study their structure and function by using site-directed mutagenesis.

Bacteriological profile and holding temperatures of street-vended foods from Addis Ababa.

A total of 150 samples of street foods comprising 30 each of 'sambussa', 'macaroni', 'lentil sandwich', 'kitfo' (raw minced meat) and 'egg sandwich' were examined for the relation between their holding temperatures and bacteriological profile. Over 90% of the samples were stored within a temperature range of 15.5-34.5 degrees C. At this holding temperature counts of coliforms and members of the Enterobacteriaceae were below detectable levels in 'sambussa' samples. In 'macaroni', 'lentil sandwich', 'kitfo' and 'egg sandwich' these counts were higher than 10(6) cfu g(-1) in most cases. Over 70% of the street food samples had aerobic mesophilic counts higher than 10(7) cfu g(-1). Of the total of 1552 bacterial strains isolated from the different food samples, Bacillus spp. (29.1%), staphylococci (22.8%) and micrococci (15.4%) were among the dominant groups. Members of the family Enterobacteriaceae (14.5%) were also frequently encountered.

Some microbiological and biochemical studies on the fermentation of 'awaze' and 'datta', traditional Ethiopian condiments.

The microbial and some biochemical changes during the fermentation of two Ethiopian condiments were studied. The aerobic mesophilic microflora of the ingredients of 'awaze' were dominated by Bacillus species (1.1 x 10(6) cfu/g) and lactic acid bacteria (4.5 x 10(4) cfu/g). The counts of aerobic mesophilic bacteria declined during the fermentation period. Lactic acid bacteria (LAB) reached the maximum count of 5.9 x 10(9) cfu/g at day 4 and the count remained > 10(8) cfu/g throughout the fermentation. The heterofermentative LAB dominated until day 3; thereafter the homolactics dominated the fermentation. Yeasts appeared at day 6 and increased to 2.5 x 10(6) cfu/g. In 'datta' fermentation, the count of aerobic mesophilic bacteria remained unchanged during the fermentation. LAB initiated the fermentation at a level of 7.1 x 10(4) cfu/g and reached 1.2 x 10(9) cfu/g at day 7. The homolactic LAB initiated and dominated the fermentation for the first 2 days and the heterolactics took over thereafter. Both fermentations were accompanied by declining pH and increasing titratable acidity. Salmonella typhimurium was inhibited during both fermentations within 48 h. Both 'awaze' and 'datta' had low initial contents of available protein and reducing sugars and these did not show marked differences throughout the fermentation.

Salmonella, Shigella and growth potential of other food-borne pathogens in Ethiopian street vended foods.

OBJECTIVE: To evaluate the bacteriological safety of food items sold by street vendors with regard to Salmonella and Shigella and to assess the growth potential of some foodborne pathogens in some street foods. DESIGN: Collection of street-vended foods and laboratory based microbiological analysis. SETTING: Microbiology Laboratory, Department of Biology, Addis Ababa University, Addis Ababa, Ethiopia. RESULTS: Most of the street food samples had aerobic mesophilic counts >10(7) cfu/g. Nine "kitfo" and one "egg sandwich" samples yielded Salmonella. Shigella was isolated from three "macaroni" samples. The Salmonella isolates were sensitive to all ten drugs tested but the Shigella isolates had multiple resistance against five drugs. In a challenge study, Salmonella typhimurium, Shigella flexneri and Staphylococcus aureus grew in street-vended food samples to hazardous levels within eight to twelve hours. CONCLUSION: Street foods are heavily contaminated with micro-organisms and are potential sources of food borne infections. Health hazards from street foods may be significantly minimised by consumption within four hours of preparation.

Prevalence of food-borne pathogens and growth potential of Salmonella in weaning foods from Addis Ababa, Ethiopia.

One hundred samples of ready-to-consume feeding bottle contents from outpatient infants were examined for the presence of Salmonella, Staphylococcus aureus and Bacillus cereus. Nearly all samples had very high gross bacterial contamination. Three Salmonella isolates were encountered from bottle contents made of cow's milk and gruel made from cereal blend. All belonged to group D. Of the 108, isolates 67 were Staph. aureus and 38 were B. cereus. The potential of Salmonella spp to grow in weaning foods was also determined on one common factory-produced infant food and one home-made infant food. In both items, Salmonella increased by approximately 4 log units within eight hours and reached counts as high as log 8 cfu/ml within twelve hours.

Effect of "siljo" fermentation on growth of Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes.

The fate of Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes in control gruel and fermenting "siljo" was assessed. S. aureus reached levels of 10(8) cfu/ml within 48 h in the control gruel. In fermenting "siljo" the count decreased all through the fermentation time. B.cereus was completely inhibited in fermenting "siljo" within 24 h, whereas it survived until 72 h in the control gruel. Complete inhibition of L.monocytogenes was noted at 48 h in fermenting "siljo". L.monocytogenes survived until 96 h in control gruel. Fermentation resulted in fall in pH to < 5.0 within 48-72 h and increase in titratable acidity was also noted. As "siljo" is usually consumed after 72 h of fermentation, "siljo" fermented for more than three days is safe from food intoxication caused by B. cereus or S.aureus or infection from L.monocytogenes.

Fate of Salmonella enteritidis and Salmonella typhimurium during the fermentation of siljo.

The behaviour of Salmonella enteritidis and S. typhimurium in control gruel and fermenting siljo was evaluated. S. enteritidis and S. typhimurium reached maximum levels of 10(8) cfu/ml and 10(6) cfu/ml, respectively within 48 hours in the control gruel. In fermenting "siljo", pH fell to < 5.0 within 48 hours and titratable acidity increased markedly. This resulted in the complete inhibition of S. enteritidis in 48 hours and S. typhimurium in 72 hours. Acid production by the fermenting lactic acid bacteria and components of mustard powder could have inhibited the test organisms. Since siljo is usually ready for consumption after 72 hours of fermentation, contaminating salmonellae would be eliminated before the product is consumed.

Bacteriological profile and holding temperatures of ready-to-serve food items in an open market in Awassa, Ethiopia.

Various types of ready-to-serve food items purchased at the Awassa open market were evaluated for their bacteriological profile and holding temperatures. The food items included roasted offals, fish soup, cooked and sauced macaroni and spaghetti, and shiro sauce. Spaghetti and macaroni were held at ambient temperatures (20-30 degrees C) and had high aerobic mesophilic count (> 10(6) cfu/g) and Enterobacteriaceae count (> 10(5) cfu/g). They also yielded Shigella and Staphylococcus spp. Most of the other food items were held at higher temperatures (> 40 degrees C) and the aerobic mesophilic count in most cases was relatively lower (< 10(5) cfu/g). Several bacterial genera were isolated and Micrococcus and Bacillus spp. dominated the aerobic microflora. The unhygienic conditions of the food service environment, possibilities of cross contamination from utensils and keeping food items at ambient temperatures for several hours were considered to be critical points.

Microbiology of siljo, a traditional Ethiopian fermented legume product.

Siljo was prepared by thoroughly cooking powdered horsebean (Vicia faba) in safflower (Carthamus tinctorius) extract into a semi-solid slurry and then adding to it untreated black mustard (Brassica nigra) powder after cooling to 50°C. The black mustard powder was the source of starter microorganisms, with Lactobacillus acidophilus, L. plantarum and L. delbruekii initiating and later dominating the fermentation process. The pH of the fermenting mass dropped to 4.5 within 36 h and reached 4.0 at 168 h. Aerobic mesophilic bacteria and lactic acid bacteria were each present at about 1×10(10) c.f.u./ml after 36 h of fermentation but Enterobacteriaceae were never detected. The dominant aerobic mesophilic flora consisted of Micrococcus, Bacillus and Lactobacillus spp. Crude protein, crude fat and ash increased slightly during the fermentation, with final values of around 28%, 25% and 7%, respectively, but there was a marked increase in protein availability and concentration during the fermentation.

Fate of Listeria monocytogenes during the souring of Ergo, a traditional Ethiopian fermented milk.

The growth potential of three strains of Listeria monocytogenes during the natural souring of raw milk into Ergo was studied to determine the effect of souring and container smoking on their inactivation. All three strains of L. monocytogenes grew well in sterile milk in unsmoked containers, reaching counts > 10(7) cfu/ml within 24 h at ambient temperature. Smoking of containers decreased the growth rate of the strains for 24 h but had varying effects on the strains. For all test strains, the count increased slightly (1.0 to 1.7 log units) until 12 h during the souring of Ergo in unsmoked containers. After 12 h of souring, the counts decreased steadily to undetectable levels at 48 or 60 h. Smoking of containers increased the rate of inactivation of the test organisms, and inactivation was complete at 36 h. Because Ergo is made by the natural souring of raw milk, consumers must be made aware of the potential dangers of acquiring listeriosis from fresh Ergo from raw milk.

Microbiological evaluation of tofu and tempeh during processing and storage.

Tofu samples consisting of 'Fresh Tofu', 'Herb Tofu', 'Tofu Paste', 'Fried Tofu', 'Tofu Burger', 'Smoked Tofu' and different types of herbs used for making 'Herb Tofu' were analysed for their microbiological load. Tempeh samples consisted of cook water, inoculated beans and fresh tempeh. 'Fresh Tofu' and 'Herb Tofu' had high bacterial counts (> or = 10(5) cfu/g). 'Tofu Burger' and 'Smoked Tofu' had counts around 10(4) cfu/g. 'Tofu Paste' and 'Fried Tofu' had low counts (< 10(2) cfu/g). Cutting board, knife and frequent hand contact with product were the major sources of contamination for tofu. Herbs used for making 'Herb Tofu' were highly contaminated (> 10(5) cfu/g). Cook water and cooked beans for tempeh production had lower counts (< or = 10(4) cfu/g). Initial count of fresh tempeh was high (about 10(8) cfu/g). Most products had counts of > 10(6) cfu/g after 7 days of cold storage. The microbiological quality of the product may improve if producers avoid unnecessary contamination during processing.

Microbial flora and some chemical properties of ersho, a starter for teff (Eragrostis tef) fermentation.

Ersho is a clear, yellow liquid that accumulates on the surface of fermenting teff-flour batter and is collected to serve as an inoculum for the next fermentation. The pH of ersho samples was about 3.5 and titratable acidity ranged between 3.1% and 5.7%. The mean aerobic mesophilic counts from four households varied between 6.9×10(6) and 1.3×10(8) c.f.u./ml and the aerobic bacterial flora consisted of Bacillus spp. Mean yeast counts ranged between 5.2×10(5) and 1.8×10(6) c.f.u./ml and comprised, in order of abundance, Candida milleri, Rhodotorula mucilaginosa, Kluyveromyces marxianus, Pichia naganishii and Debaromyces hansenii. Candida milleri was the most dominant isolate in all samples. About 90% of the teff flour samples had aerobic mesophilic counts ≥10(5) c.f.u./g and Gram-positive bacteria constituted about 71% of the total isolates. About 80% of samples had Enterobacteriaceae counts of 10(4) c.f.u./g.

Fate of Salmonella enteritidis and Salmonella typhimurium during the fermentation of ergo, a traditional Ethiopian sour milk.

The growth potential of Salmonella enteritidis and Salmonella typhimurium in milk in smoked and non-smoked containers and their inhibition by lactic acid bacteria was determined. In the absence of lactic acid bacteria, both Salmonella strains could grow to the level of 10(8) cfu/ml within 12 h. Smoking of containers significantly retarded Salmonella growth only until 12 h. Growth of lactic acid bacteria in souring milk retarded growth of Salmonella strains and complete inhibition was observed between 48 and 60 h at pH and titratable acidity values of 3.7 and 0.70%, respectively. The synergistic effect of lower pH, acids and smoking was important in the complete inhibition of the test organisms. Although ergo was preferably consumed after 24 h of fermentation, the Salmonella strains were not completely inhibited at this time. Thus, traditional making of ergo by the natural fermentation of raw milk could be hazardous to health. The use of a three-day old ergo as a starter for boiled milk is recommended to ensure the wholesomeness of ergo.

Growth of Bacillus cereus in fermenting tempeh made from various beans and its inhibition by Lactobacillus plantarum.

Counts of Bacillus cereus reached ca 10(8) cfu/g within 40 h in fermenting unacidified horsebean tempeh and resulted in complete spoilage of the product. In fermenting unacidified pea, chickpea and soybean tempeh, B. cereus counts reached 10(6)-10(7) cfu/g, although the products were not spoiled. Inoculation of these unacidified beans with Lactobacillus plantarum decreased the final count of B. cereus by 2 log units, but had no effect on its growth in unacidified horsebean tempeh and its subsequent spoilage. Acidification of the beans during soaking resulted in a lower rate of B. cereus growth during fermentation. Inoculation of acidified beans with Lact. plantarum resulted in a markedly lower growth rate of B. cereus. In an associative broth culture study, B. cereus was completely inhibited by Lact. plantarum at pH values of about 5.5. Lactobacillus plantarum may be used to control the growth of B. cereus during tempeh production.

The microflora of soak water during tempeh production from various beans.

The microflora of soak water was studied during the soaking of horsebean, pea, chickpea and soybean for tempeh production. Lactic streptococci dominated the flora in both unacidified and acidified soak water. Coliforms and yeast were found only in unacidified soak water. Growth of micro-organisms in acidified and unacidified soak water resulted in a decrease in pH value of the cooked beans. Microbial acidification during soaking is considered to be important in tempeh production.

Microbiological quality of ayib, a traditional Ethiopian cottage cheese.

One-hundred samples of ayib, a traditional Ethiopian cottage cheese, were purchased from Awassa market and analysed for their aerobic mesophilic counts, psychrotrophic counts, yeasts and molds, coliforms, spore-formers, enterococci, lactic acid bacteria. Listeria monocytogenes, staphylococci and Bacillus cereus. The majority of the samples showed counts of mesophilic aerobic bacteria, yeasts and enterococci of 10(8), 10(7) and 10(7) cfu/g. About 55% of the samples were positive for coliforms and faecal coliforms. Listeria spp. were not detected in any of the samples. B. cereus and S. aureus were isolated at varying frequencies but at low numbers (10(2)-10(3)). The pH value of the samples varied between 3.3 and 4.6 with about 40% having pH lower than 3.7.

Effect of curd-cooking temperatures on the microbiological quality ofayib, a traditional Ethiopian cottage cheese.

Ayib was made following traditional methods of curd cooking at 40°, 50°, 60° and 70°C requiring 10 h, 7 h, 145 min and 55 min, respectively. During the natural fermentation of raw milk into sour milk (curd), the count of all groups of microorganisms increased by at least a 100-fold. When the curd was subsequently cooked at 40°C, counts of enterococci and members of Enterobacteriaceae decreased by a 100-fold and lactic acid bacteria and staphylococci by a 100-fold. At 50°C, the count of enterococci, members of Enterobacterlaceae and staphylococci was lower than could be detected (<10(2) c.f.u./g). Yeasts, moulds and lactic acid bacteria still had counts of about 10(5) c.f.u./g. The total aerobic count decreased by a 100-fold but was still high (>10(7) c.f.u./g). At 60°C, yeasts and moulds decreased by 1000-fold and at 70°C they decreased below detectable levels (<10(2) c.f.u./g). This latter temperature is thus recommended as it results in a less contaminated and saferayib.

Salmonella and Shigella in adult diarrhoea in Addis Ababa--prevalence and antibiograms.

Ninety Shigella and 45 Salmonella strains were isolated from 1000 adult diarrhoeal out-patients from various hospitals and clinics in Addis Ababa. The Shigella species were isolated in the order of frequency of S. flexneri, S. dysenteriae, S. boydii and S. sonnei and the Salmonella in the order of Group C, Group B, S. typhi, other Group D and Groups A and E. Almost all Shigella isolates were sensitive to cephalothin, gentamicin, kanamycin, polymyxin B and trimethoprim-sulphamethoxazole. About 17% were sensitive to the 11 drugs tested. Multiple resistance was detected in 62%, the most common to six drugs (27%). All Salmonella isolates were sensitive to gentamicin, polymyxin B and trimethoprim-sulphamethoxazole. About 69% were sensitive to all drugs tested. 22% were multiply resistant and the most common was to eight drugs (18%).