Wael F. El-Tras

Anticandidal action of fungal chitosan against Candida albicans

The anticandidal activity of four fungal chitosan types, produced from Mucor rouxii DSM-1191, against three Candida albicans strains was determined. The most bioactive chitosan type, to inhibit C. albicans growth, had the lowest molecular weight (32 kDa) and the highest deacetylation degree (94%). Water soluble types had stronger anticandidal activity than soluble types in 1% acetic acid solution. Scanning electron micrographs of treated C. albicans with fungal chitosan proved that chitosan principally interact with yeast cell wall, causing severe swelling and asymmetric rough shapes, and subsequent cell wall lyses with the prolonging of exposure time. Fungal chitosan could be recommended for C. albicans control as a powerful and safe alternative to synthetic and chemical fungicides.

Brucella spp. infection in large ruminants in an endemic area of Egypt: cross-sectional study investigating seroprevalence, risk factors and livestock owner's knowledge, attitudes and practices (KAPs)

BackgroundBrucellosis is regarded as one of the major zoonotic infections worldwide. It was first reported in Egypt in 1939 and is now endemic, the predominate species of Brucella in cattle and buffalo in Egypt is B. melitensis. The aim of the study was to estimate seroprevalence of Brucella spp. in cattle and buffalo reared in households in an Egyptian village, identify risk factors for animals testing seropositive and to assess the knowledge, attitudes and practices (KAPs) of livestock owners with regards to brucellosis.MethodsA cross-sectional study was carried out in a village in Menufiya Governorate of Egypt. In June and July 2009, 107 households were selected using systematic sample and all lactating cattle and buffalo present in the household were sampled and tested for antibodies against Brucella spp. In addition, a questionnaire collecting information on potential risk factors for Brucella spp. infection in cattle and buffalo was administered to the household member responsible for rearing the livestock. Between December 2009 and February 2010 households were revisited and a second questionnaire regarding KAPs associated with brucellosis was administered.ResultsTrue individual and household seroprevalence were estimated to be 11.0% (95% CI: 3.06% to 18.4%) and 15.5% (95% CI: 6.61% to 24.7%), respectively. Cattle and buffalo kept in a household with sheep and goats had 6.32 (95% CI: 1.44 to 27.9) times the odds of testing seropositive for Brucella spp., compared to cattle and buffalo that were not. Most participants in the study stated that livestock owners assist in the parturition of ruminants without wearing gloves and that some farmers sell animals which they suspect are Brucella infected to butchers or at market. Many participants made their livestocks milk into cheese and other dairy products without pasteurising it.ConclusionsBrucellosis was endemic at high levels, in the current study. Although livestock owners had good general knowledge of brucellosis, they still appeared to participate in high-risk behaviours, which may contribute to the high seroprevalence in the area. Veterinarians, public health authorities and other community leaders need to collaborate to control the disease in animals and to manage the risk of human exposure.

Brucella infection in fresh water fish: Evidence for natural infection of Nile catfish, Clarias gariepinus, with Brucella melitensis

Brucellosis is endemic among ruminants in the Nile Delta region of Egypt, where recent reports suggest that the incidence of human infection is increasing. In this region the practice of throwing animal waste into Nile canals is common. As a result, water can be contaminated with potential zoonotic pathogens such as B. melitensis that could infect fish. This study aimed at isolating and characterizing B. melitensis from Nile catfish. Serum samples from 120 catfish captured from Nile canals and 120 farmed catfish were tested for the presence of antibodies against Brucella spp. by using the Rose Bengal Test (RBT) and the Rivanol test (Riv T). Skin swabs from all fish and samples from internal organs (liver, kidney and spleen) from all serologically positive fish were cultured to identify B. melitensis biovar 3 isolates. Polymerase Chain Reaction (PCR) was used to confirm the results. 9.2% and 8.3% of serum samples from Nile catfish were positive by RBT and Riv T, respectively. None of the samples from farmed catfish were seropositive. B. melitensis biovar 3 was isolated from 5.8%, 4.2%, 5.8% and 13.3% of liver, kidney and spleen samples and skin swabs, respectively. To our knowledge this is the first report of isolation of B. melitensis biovar 3 from fresh water fish. Our results suggest that Nile catfish are naturally infected with B. melitensis biovar 3 and this may play a role in the epidemiology of brucellosis. The public should be aware of the consequences of disposing of animal waste into the canals and public health authorities should consider the potential role of catfish as a source of infection.

Antimicrobial textile treated with chitosan from Aspergillus niger mycelial waste

The waste biomass of Aspergillus niger, following citric acid production, was used as a source for fungal chitosan extraction. The produced chitosan was characterized with deacetylation degree of 89.6%, a molecular weight of 25,000 dalton, 97% solubility in 1% acetic acid solution and comparable FT-IR spectra to standard shrimp chitosan. Fungal chitosan was applied as a cotton fabric finishing agent using pad-dry-cure method. The topographical structure of chitosan-treated fabrics (CTF) was much improved compared with control fabrics. CTF, after durability tests, exhibited a powerful antimicrobial activity against both E. coli and Candida albicans, the captured micrographs for E. coli cells contacted with CTF showed a complete lysis of cell walls with the prolonging contact time. The produced antimicrobial CTF could be proposed as a suitable material for many medical and hygienic applications.

Anticandidal activity of pomegranate peel extract aerosol as an applicable sanitizing method

Pomegranate is a wonderful fruit from the paradise which contains a wide variety of precious phytochemical compounds applicable in the fields of therapeutics and health care. Candida albicans is the most common etiological agent for many clinical mycoses which could lead to human and animal death. Determination of the anticandidal activity of pomegranate peel extracts (PPE), and application of PPE aerosol as sanitizer agent against C. albicans contamination were investigated. Agar diffusion assay and broth microdilution susceptibility test were applied for qualitative and quantitative determining the PPE anticandidal activity, respectively, versus commonly used fungicides. Aerosolization of PPE using an experimentally designed sanitizer room was applied for examining C. albicans sanitation potentiality of extract. PPE exhibited potent anticandidal activity against C. albicans strains comparing with standard fungicides in both used susceptibility techniques. Methanol, ethanol and water extracts were the most effective for inhibiting C. albicans growth. PPE aerosol was an efficient method for complete sanitizing of semi‐closed places against C. albicans growth. Application of PPE aerosol is a proper sanitizing method for preventing C. albicans contamination and growth in suspected places.

Infants exposure to aflatoxin M1 as a novel foodborne zoonosis

Occurrence of aflatoxin M(1) (AFM(1)) in infant formula milk powder (IFMP) and maternal breast milk (MBM) was investigated as a risk factor affects the health of newborns in Egypt. A total of 125 IFMP and 125 MBM samples were collected and examined for the presence of AFM(1) using competitive ELISA test. The results indicated that the relative risk (RR) of exposure to AFM(1) via consumption of MBM was higher than IFMP (RR; 1.6, 95%CI; 1.28-2.03, p=0.0001). The mean concentrations of AFM(1) were significantly differed (p<0.0001) between MBM (74.413 ± 7.070 ng/l) and IFMP (9.796 ± 1.036 ng/l). High frequency distributions were detected within the range of 5-25 ng/l and >50-100 ng/l in IFMP and MBM, respectively. The average daily exposure of newborns to AFM(1) via consumption of MBM and IFMP was 52.684 and 8.170 ng, respectively, with a significant difference at p<0.0001. Consumption of raw milk by lactating mothers exhibited a significant correlation (p<0.0001) with the presence of AFM(1) in their milk. In conclusion, this work established a pioneering concept that AFM(1) may be considered as an etiological factor for a novel foodborne zoonosis identified as Aflatoxicosis M(1).

Risk of Toxocara canis eggs in stray and domestic dog hair in Egypt

The aim of the study was to assess whether the hair of stray and domestic dogs in Egypt was contaminated with the eggs of the zoonotic parasite Toxocara canis, and also to identify risk factors for T. canis for contamination. Paired samples of hair and feces were collected from 53 stray and 47 domestic dogs, and hair samples were obtained from a further 11 stray and 9 domestic dogs. All samples were examined to identify T. canis eggs and, if eggs were found, their maturation stage. Eggs were identified in 26.6% of stray and 10.7% of domestic dogs hair samples. A significantly increased risk of embryonated T. canis eggs in hair samples was found in stray dogs (p=0.04), stray dogs had 3.18 (95% CI: 1.04-9.74) times the odds of having T. canis eggs present compared with domestic dogs. There was also a significant difference (p=0.02) between the mean quantity of eggs per gram in stray (77.6±6.54) and domestic (48.7±6.65) dogs hair. Fecal examination found a T. canis egg prevalence of 35.8% and 21.3% in stray and domestic dogs, respectively. As no domestic dogs which were positive from hair samples had negative fecal samples, this indicates that the presence of T. canis eggs in hair is probably due to self contamination. Two stray dogs had positive hair samples but negative fecal samples indicating that contamination may also be environmental. As both non-embryonated and embryonated T. canis eggs were found in the hair of domestic dogs, direct contact with dogs may be a potential risk factor for transmission of T. canis eggs to humans.

Cross-Species Surveillance of Leptospira in Domestic and Peri-Domestic Animals in Mahalla City, Gharbeya Governorate, Egypt

A survey of 179 animals (black rats, dogs, sheep, buffaloes, cattle, donkeys, weasels, and cats) for Leptospira infection was conducted in Mahalla City (Lower Egypt). Blood, urine, and kidney were collected and tested by culture, microscopic agglutination test (MAT), and/or polymerase chain reaction (PCR). Among rats, 26% were positive by PCR, including 7% that were also positive by culture for L. interrogans serovars Grippotyphosa, Pyrogenes, and Icterohaemorrhagiae. L. borpetersenii serovar Polonica was isolated for the first time in Egypt in three rats. MAT titers ≥ 1:800 were observed in 11% of rats and 12% of dogs. L. interrogans serovar Grippotyphosa was detected in one cat. Sheep and donkeys were negative for leptospirosis by all methods. Buffaloes and cattle were seropositive in 20% and 44% of animals, respectively. Data indicate that several pathogenic serovars are circulating in the animals, which may pose exposure risks and account for high rates of acute febrile illness.

Seroprevalence of Hepatitis E Virus in Humans and Geographically Matched Food Animals in Egypt

The aim of current study was to investigate the epidemiology of Hepatitis E virus (HEV) in humans and geographically matched food animals as a novel zoonotic assessment in Egypt. Blood samples were collected from patients who had a history of jaundice and attended to fever and general hospitals. Animal blood samples were collected from cows, buffaloes, sheep and goats convenient to HEV seropositive humans. Enzyme Immuno Assay (EIA) protocol was used to determine IgG anti‐HEV. Sex and pregnancy were investigated as potential risk factors for HEV infection. Of 134 examined humans, 51 (38.1%) were positive for IgG anti‐HEV. The males showed 26.8% seropositivity while the recorded female seropositivity was 50.8%, with a significant difference at P = 0.005, Odds Ratio (OR) = 0.35 at 95% confidence interval (CI): 0.17–0.73. There was a significant difference at P = 0.02 between seropositivity in pregnant (25%) and non‐pregnant women (59.6%); OR was 0.23 (95% CI: 0.06–0.81). Anorexia was the most common symptom whereas paraesthesia and back pain were the least within icteric seropositive HEV humans. Hepatitis E virus seropositivity was recorded in 21.6%, 14%, 4.4% and 9.4% from examined cows, buffaloes, sheep and goats, respectively. The infected food animals were convenient to positive HEV humans who may declare the epidemiological picture of potential zoonotic HEV.

Surface Decontamination and Quality Enhancement in Meat Steaks Using Plant Extracts as Natural Biopreservatives

Nine plant extracts were evaluated as biopreservatives to decontaminate and maintain the quality of meat steaks. Most of the extracts exhibited a remarkable antibacterial activity against antibiotic resistant strains from Salmonella Typhimurium and Staphylococcus aureus. The pomegranate peel extract (PPE), cinnamon bark extract (CBE), and lemon grass leaves extract (LGE) were the most effective as bactericides, with minimal inhibitory concentrations (MIC) of 250, 350, and 550 μg/mL, respectively. The most effective treatments, for decontaminating meat steak surfaces, were the application of combined PPE, CBE, and LGE at their MIC values and the treatment with double MIC from PPE; these treatments resulted in complete bacterial inhibitions during the first 2 days of storage period for 7 days. The sensory evaluation of treated steaks revealed that these two treatments had the highest panelist overall scores. The highest scores, for individual attributes, were observed in the treated steaks with double MIC from PPE. Application of plant extracts could be impressively recommended for comprehensive meat decontamination and quality attributes enhancement.