Distribution of classical enterotoxin genes in staphylococci from milk of cows with- and without mastitis and the cowshed environment.

The aim of this study was to analyze by PCR 185 isolates of Staphylococcus from milk of cows with- and without mastitis and from the cowsheds environment for their potential ability to produce five classical staphylococcal enterotoxins. Among S. aureus isolates 8 (32%) carried enterotoxin genes and only 2 of them had more than one gene. The enterotoxin genes were detected in 22 (13.7%) coagulase-negative staphylococci (CNS) isolates, among them in 9 (11.4%) isolates of S. xylosus, 5 (16.7%) S. sciuri, 3 (10.3%) S. epidermidis and in 5 (22.7%) Staphylococcus spp. In some CNS 2 or 3 genes were detected simultaneously. Among the investigated enterotoxin genes, sec was the most prevalent (70%). The genes encoding enterotoxin B and D were detected in 5 (16.7%) and 6 (20%) isolates, respectively. The lowest number of isolates had sea and see genes. The genes encoding enterotoxins were often identified in staphylococci from milk of cows with mastitis (73.4% of detected genes), while only 6 (20%) isolates from milk of cows without mastitis and 2 (6.6%) isolates from cowshed environment were positive for enterotoxin genes. The results showed that CNS from bovine milk, like S. aureus, carried enterotoxin genes and may pose a risk for public health.

Motility activity, slime production, biofilm formation and genetic typing by ERIC-PCR for Pseudomonas aeruginosa strains isolated from bovine and other sources (human and environment).

The molecular-typing strategy, ERIC-PCR was used in an attempt to determine the genomic relationship of 28 P. aeruginosa strains isolated from faeces of healthy bovine, bovine mastitis and from faeces of hospital patients as well as from environment. ERIC-PCR fingerprinting revealed large molecular differentiation within this group of isolates. Twenty two out of 28 strains tested generated unique patterns of DNA bands and only three genotypes consisted of two isolates each were identified. We also tested the P. aeruginosa isolates for their ability to form a biofilm on abiotic surfaces including polyvinylchloride and polystyrene. Different biofilm-forming abilities were demonstrated among strains; however, most of them (64.3%) showed moderate-biofilm forming ability. The strains with increased swimming and twitching motility displayed elevated biofilm formation. However, a negative correlation was found between slime and initial biofilm production. On the basis of the results obtained, we suggest that there are no major differences in phenotypic properties between P. aeruginosa strains isolated from different sources.

Regular consumption of Nile river fish could ameliorate the low milk DHA of Southern Sudanese women living in Khartoum City area.

We have reported that milk of Northern Sudanese women contained very low level of docosahexaenoic acid (DHA). This was puzzling since the mothers were not malnourished and some had claimed to eat fish from time to time. War-displaced Southern Sudanese live in Khartoum City and its vicinity. They are distinct in genetic background and traditional dietary culture from the Northerners. Milk DHA is influenced by diet and ethnicity. Fatty acid content of Southern Sudanese milk, and six of the popular River Nile fish species were evaluated. Mature milk compared with transition milk had lower arachidonic (AA, 0.6±0.19 vs. 0.75±0.3; p<0.001), adrenic (0.14±0.1 vs. 0.33±0.23), osbond (0.07±0.05 vs. 0.14±0.08; p<0.0001), eicosapentaenoic (0.04±0.02 vs.0.08±0.07; p<0.01) and DHA (0.10±0.07 vs. 0.16±0.1; p=0.003) acids. The milk of the Southerners like their counterparts from the North had low DHA and total n-3 and high AA and total n-6 levels. Regular consumption of the local fish could provide adequate DHA to help enrich their milk.

Virulence factors and ability of staphylococci from bovine milk and the cowshed environment to biofilm formation.

The aim of this study was to examine virulence factors and the ability of S. aureus and CNS species isolated from milk of cows with mastitis to form biofilm, and to compare them with virulence factors of staphylococci from milk of cows without mastitis and cowshed environment. Most of S. aureus strains from cows with mastitis showed haemolytic activity (93.9%), among them 72.7% and 21.2% produced alpha- and beta-haemolysin, respectively. S. aureus from cows with mastitis symptoms produced proteases (above 48%) and esterase (42.4%). The highly significant relationship between the number of S. xylosus strains producing haemolysins (62%) and the origin of these strains from milk of cows with mastitis was observed. The ability to produce proteases was significantly associated with S. sciuri from milk of cows with mastitis. The ability of biofilm formation by staphylococcal strains from milk of cows with mastitis was greater than in strains from milk of cows without mastitis and the difference was significant (p < or = 0.05). The highest percentage of strains from milk of cows with mastitis were weak biofilm formers (48.6%), while 40% and 11.4% of strains were moderate and strong biofilm producers, respectively. S. xylosus showed the highest ability to form biofilm, while the lowest ability to form biofilm was observed in S. aureus and S. epidermidis. In conclusion, production of exotoxins and enzymes, and ability of biofilm formation shown by many CNS isolated from milk of cows with mastitis symptoms indicates that these features are important in pathogenesis of this disease.

Sudanese women's and neonates' vitamin A status.

We have determined and compared the concentration levels of retinol and ß-carotene in the plasma of three Sudanese women groups (displaced southern Sudanese women (DSSW), non-displaced southern Sudanese (NDSSW) and northern Sudanese women (NSW)), who were either pregnant or non-pregnant; and in their neonates (cord plasma). Plasma samples were analysed by high-performance liquid chromatography using reversed-phase column and diode-array detectors. The results revealed that retinol and ß-carotene in the plasma of non-pregnant and pregnant women in the three groups were very low compared with studies reported elsewhere. Over 50% of pregnant DSSW and NDSSW had a low concentration of retinol plasma (< 0.70 µmol/L), and about 15-20% were deficient (< 0.35 µmol/L) according to World Health Organization criteria. Although the average retinol concentration in the plasma of pregnant NSW was > 0.70 µmol/L, which suggests sufficiency status, 32% showed lower levels and 10% were deficient. Plasma retinol ß-carotene levels in the neonates' cords were also lower than their mothers and in comparison with other studies. These findings are in agreement with previous survey data and clinical reports, which also suggest that vitamin A deficiency is of great concern in the country. We concluded that insufficient intake of food of animal origin and repeated malarial and other parasitic diseases are the most likely causes of vitamin A deficiency.

Phenotypic and genotypic antimicrobial resistance of staphylococci from bovine milk.

The aim of this study was to examine phenotypic and genotypic antimicrobial resistance of staphylococci from milk samples from cows with subclinical and clinical mastitis and from cows without mastitis symptoms to methicillin, tetracyclines, macrolides and lincosamides (ML). Of 207 strains, including 34 S. aureus and 173 coagulase-negative staphylococci (CNS), 11 (6.4%) CNS strains were phenotypically resistant to methicillin. The mecA gene was detected by PCR only in two S. xylosus strains and one strain of S. epidermidis and S. simulans. No methicillin-resistant S. aureus strains were observed. In methicillin-resistant strains with mecA, gene resistance to other investigated antibiotics was not observed. Phenotypic resistance to tetracycline was detected in 11.0% of CNS strains and 47.4% of them carried the tetK gene. Of 173 CNS strains studied, 27 (15.6%) were resistant to at least one ML antibiotic. The resistance gene ermC was detected in 55.5% of the 27 ML-resistant strains. The ermA and ermB genes were detected in 14.8% and 11.1% of ML-resistant CNS strains, respectively. Antimicrobial resistance to methicillin, tetracyclines and macrolides was detected more frequently in staphylococcal strains from clinical mastitis compared to animals with subclinical symptoms and without mastitis, while the resistance to lincosamides showed a similar frequency in all groups of cows. In conclusion, CNS species from bovine milk differ in phenotypic and genotypic antimicrobial resistance profiles, and the use of PCR technique alone for the detection of methicillin, macrolide, lincosamide and tetyracycline resistance in CNS from cattle is not reliable.

Antimicrobial resistance and genotypes of staphylococci from bovine milk and the cowshed environment.

Investigation of antimicrobial resistance and genetic relatedness of staphylococci from milk of cows with mastitis and cowshed environment was the aim of this study. Antimicrobial resistance against 14 antimicrobials were determined by using a disc diffusion method. Genetic similarity between the most frequently isolated species was analysed by PFGE (pulsed-field gel electrophoresis). Haemolytic activity, DNase, protease and esterase production was also investigated. Coagulase-negative Staphylococcus species were isolated from 30.8% of milk samples from cows with mastitis. The most frequently isolated species was Staphylococcus xylosus and yield of these organisms was significantly associated with milk of mastitis cows. S. epidermidis was a predominant penicillin-resistant species. High frequency of resistance to lincomycin was observed among isolates of S. sciuri (54.2%) and S. xylosus (25.9%) from cows with mastitis. PFGE (pulsed-field gel electrophoresis) analysis of 29 Staphylococcus aureus isolates showed the presence of 17 PFGE pulsotypes. Isolates of S. sciuri (n = 36) had unique PFGE patterns. Some S. xylosus isolates from milk and milker's hands had the same PFGE pulsotypes, and this observation could indicate that dairyman may be a potential source of the infection. The pulsotype of each of the remaining isolates of S. xylosus suggested that they might have come from common environmental sources; however, these isolates differed in antibiotic resistance pattern or virulence traits. Therefore, knowledge about antibiotic sensitivity pattern and virulence factors of a CNS isolate, besides its genotype, may be informative in tracking the source of the infection.

Dietary intake of Sudanese women: a comparative assessment of nutrient intake of displaced and non-displaced women.

OBJECTIVES: To determine the daily intake of essential micro- and macronutrients in Sudanese women, with specific focus on dietary fat and essential fatty acids, and compare the dietary intakes of internally displaced women with those of the non-displaced population. METHODS: Dietary intakes of displaced southern (n=44) and non-displaced southern (n=30) and northern (n=39) Sudanese women were obtained by single 24-hour recall method, and daily nutrient intakes were calculated using 'Foodbase' nutritional software. The displaced women were recruited from Mayo and Soba Aradi camps, south of Khartoum city; and non-displaced southern and northern Sudanese women were recruited from antenatal clinics, universities, hospitals and the community in Khartoum city and Omdurman, Sudan. RESULTS: Carbohydrates provided over 60% of dietary energy for all the Sudanese women groups. The displaced women had significantly lower intake of energy (1744 ± 344 kcal/d), starch (p<0.001) and carbohydrates (312 ± 11 g/d, p<0.01) than both non-displaced southern (1972 ± 229 kcal/d energy, 358 ± 56 g/d carbohydrates) and northern Sudanese women (1988 ± 226 kcal/d energy, 357 ± 56g/d carbohydrates). Fat intake was also lower in the displaced group (34.1 ± 11.9 g/d) than in the non-displaced counterpart (38.5 ± 10.2 g/d) (p<0.05), but was not significantly different from northern Sudanese women (37.6 ± 10.6, p>0.05). Intakes of iodine (33.60-56.96 µg/d), zinc (7.12-9.92 mg/d), retinol (226.1-349.7 µg/d), riboflavin (0.44-0.70 mg/d) and docosahexaenoic acid (11.70-33.49 mg/d) amongst Sudanese women were very low compared with recommendations. CONCLUSION: The Sudanese diet was less diverse and differences in energy and nutrients intakes between groups were due to the amounts of food consumed. This view is supported by a lack of significant differences when intakes were expressed as proportion of whole energy between all groups of women.

Analysis of occurrence of virulence genes among Yersinia enterocolitica isolates belonging to different biotypes and serotypes.

The 150 Y enterocolitica strains isolated from humans and from pigs belonged to biotypes 4 (68.7%), 1A (18.7%) and 2 (4%), or were biochemically untypeable (8.6%). Biotype 4 was comprised of Y. enterocolitica strains representing serotype O:3, within biotype 1A the strains either belonged to serotypes O:5 and O:6 or were untypeable, and biotype 2 was represented by the strains of serotype O:9. The strains which were biochemically untypeable belonged to serotypes O:5, O:6 and O:3. Among the strains tested there also were those of an unidentified biotype and serotype. Nearly all the strains of biotype 1A represented genotype ystB+myfA+, and few belonged to genotype ystB+. The presence of the ystB gene in the strains of biotype 1A and only occasional occurrence of the gene in the other biotypes makes ystB a distinguishing marker of biotype 1A. The strains of genotype ystA+ail+myfA+yadA+ predominated in biotype 4 (serotype O:3). The strains of biotype 2 (serotype O:9) represented genotype ystA+ail+myfA+, and the plasmid yadA gene was detected in some of them. Within the group of biochemically untypeable strains ystB- and myfA-specific PCR products were mainly obtained. The genotypes determined for the tested biotypes and serotypes of Y. enterocolitica, based upon the selected genes of virulence, can be applied as distinguishing markers and indicators of the potential virulence of Y. enterocolitica strains, excluding bioserotyping.

The application of PCR to the identification of selected virulence markers of Yersinia genus.

The subject of this study was thirty nine strains of Yersinia enterocolitica, isolated from faeces of humans who showed symptoms typical of intestinal yersiniosis, and seventy strains of Y enterocolitica, four strains of Y. pseudotuberculosis, and one strain of Y. kristensenii from healthy pigs. In the population tested the following serogroups appeared: O3, O9, O2, O5. A PCR was used to detect the presence of pathogenic chromosomal markers, such as myfA and inv genes of the tested Yersinia species. Among Y. enterocolitica strains isolated from humans and belonging to serogroup O3 (thirty four strains) and serogroup O9 (five strains) thirty three Y. enterocolitica O3 strains and four Y. enterocolifica O9 strains, gave a positive reaction to the nmyfA gene, yielding a fragment of 280 base pairs (bp). Among seventy Y. enterocolitica strains isolated from pigs forty strains belonging to serogroup O3 and fifteen strains belonging to serogroup O9 gave a positive reaction to the myfA gene. The presence of 390 bp amplified products, corresponding to the inv gene fragment, was detected in PCR products of three Y pseudotlluberculosis strains from pigs and only in one Y. enterocolitica O3 strain from humans, which had no myfA gene. The results obtained show that the myfA gene is only present in the strains that belong to pathogenic serotypes of Y. enterocolitica. The myfA gene prevailed in the Y. enterocolitica O3 and O9 strains from humans but was less common in the Y. enterocolitica O3 and O9 strains from pigs.

The activity of chosen bacteriophages on Yersinia enterocolitica strains.

The aim of the present study was to evaluate the lytic activity of three bacteriophages on Yersinia enterocolitica strains isolated from humans and pigs. The Y. enterocolitica strains tested belonged to 0:3, 0:9 and 0:2 serogroups. The ZD5 phage was obtained from a water sample, but remaining phages were obtained from the lysogenic Y. frederiksenii 7291 and Y. enterocolitica 8684 strains. All the Y. enterocolitica strains tested which belonged to 0:9 serogroup did not show any susceptibility to the bacteriophages used. The bacteriophages tested showed different lytic activity on the Y. enterocolitica 0:3 strains investigated. The phage susceptibility of Y. enterocolitica 0:3 strains revealed 9 different phage patterns. ZD5 phage showed the highest lytic activity, because it produced confluent lysis of the most Y. enterocolitica 0:3 strains tested. The Y. enterocolitica 0:2 strains isolated from pigs showed the similar phage susceptibility. The Y. kristensenii and Y. pseudotuberculosis strains tested were not sensitive to the bacteriophages used.

[Evaluation of hydrophobic properties of Yersinia enterocolitica strains isolated from humans and pigs]. / Ocena hydrofobowych wlasciwosci szczepów Yersinia enterocolitica wyizolowanych od ludzi i trzody chlewnej.

The aim of the study was to evaluate the hydrophobic properties of Yersinia enterocolitica and to determine the influence of the culture conditions, such as: type of medium, temperature, and duration of the culture on the manifestation of these properties. The subject of the study were 117 of Y. enterocolitica strains isolated from humans and pigs. The ammonium sulphate salt aggregation test according to Lindahl modified method was used to evaluate the hydrophobic properties of Y. enterocolitica strains. Strains of Y. enterocolitica were cultured for 24 h at 25 degrees C on TSA (Difco) medium. During investigation of the influence of the culture conditions the chosen strains were incubated for 24 h and 48 h at 25 degrees C and 37 degrees C on TSA (Difco), LB (Difco), enrichment agar (Biomed), and enrichment agar with 5% sheep blood (Graso). A total of 44.5%, 17.9%, 9.4%, and 28.2% strains of Y. enterocolitica showed very strong hydrophobic properties, strong hydrophobic properties, some hydrophobic properties, and were non-hydrophobic, respectively when strains of Y. enterocolitica were cultured for 24 h at 25 degrees C on TSA medium. A total of 75.5% strains isolated from humans showed very strong hydrophobic properties and 13.5% strains were non-hydrophobic. Among strains isolated from pigs 30% showed very strong hydrophobic properties but 35% were non-hydrophobic. The hydrophobic properties of Y. enterocolitica depended on the temperature, duration of the culture and the type of media. The highest number of strains with very strong hydrophobic properties (89.6%) was obtained after 48 h of the incubation at 37 degrees C on the enrichment agar with 5% sheep blood. The highest number of non-hydrophobic strains of Y. enterocolitica (28.5%) was obtained after 24 h at 25 degrees C on TSA medium.

[Analysis of bacteriocinogenic properties of Yersinia enterocolitica strains]. / Analiza bakteriocynogennych wlasciwosci szczepów Yersinia enterocolitica.

The aim of the study was the investigation of bacteriocinogenic properties of 102 Yersinia enterocolitica strains. The influence of selected factors on the production of bacteriocins by Y. enterocolitica and properties of jersiniacin 44JPSBKOH were also investigated. Bacteriocinogenic properties of Y. enterocolitica strains were tested by using the delayed cross-streaking method. It was found that the production of bacteriocins by Y. enterocolitica depended on the type of media on which the producer and indicator strains were grown. It turned out that some strains of Y. enterocolitica showed bacteriocinogenic properties at 25 degrees C, 30 degrees C and 37 degrees C irrespective of the presence of manganese ions in medium. In the presence of iron ions these strains showed bacteriocinogenic properties only at 25 degrees C. Y. enterocolitica strains which required Mn2+ or Mn7+ ions for bacteriocins production showed this activity only at 25 degrees C but in presence of Fe3+ ions they had no bacteriocinogenic properties. The partially purified jersiniacin 44JPSBKOH is a protein, its molecular weight was estimated to be 40 kDa. Yersiniacin 44JPSBKOH was active in the pH range of 3 to 9. Its bactericidal activity was rapidly lost when heated to 100 degrees C and treated with proteolytic enzymes. Yersiniacin 44JPSBKOH showed bactericidal activity against other Y. enterocolitica strains and some strains of Pseudomonas aeruginosa isolated from humans.

[Results of one-year observation of the visual system of premature infants]. / Wyniki rocznej obserwacji narzadu wzroku dzieci przedwczesnie urodzonych.

65 infants with gestational age 25-36 weeks and birth weight 800-2650 g were observed. Retinopathy of prematurity was found in 27 infants; in 9 eyes of 7 infants cryotherapy was applied. Examination at the age of 12 months evaluated: position and movements of the eye, refraction, visual acuity with preferential looking method, as well as anterior segment and fundus of the eye. Disturbances in eye position and movements were observed in 26 infants. Emmetropia was found in 16 eyes, 77 were hypermetropic and 27 myopic. The length of the eyeballs ranged from 14.6 to 22.5 mm. Visual acuity was determined in 39 infants, in 9 of them only binocular. It was 0.2 (normal) in 22 eyes, > in 2 and < in 36 eyes.