Vol. 34, January, 2013

1/34 CEFOXITIN AND OXACILLIN DISKS AS A SCREENING TOOL FOR METHICILLIN RESISTANCE AMONG CLINICAL ISOLATES OF STAPHYLOCOCCUS AUREUS IN ZARIA, KADUNA STATE.

Ahmed S. Opaluw; Olonitola, O.S.; Taysir R. Hafiz*and Yakubu S.E.

Department of Medical Microbiology, Faculty of Medicine, A.B.U.T.H; Zaria.

* Department of Microbiology and Immunology, Faculty of Medicine, Al Azhar University, Cairo, Egypt.

A study evaluating cefoxitin and oxacillin disk as a screening tool for methicillin resistance among clinical isolates of Staphylococcus aureus was undertaken. A total of 560 samples were examined and a prevalence of 9.1% (n=51) was recorded for staphylococcal infections. Of these 31.3% (n=16) isolates were from wound, 50.9% (n=26) were from urinogenitals, 13.7% (n=7) from blood and 3.9% (n=2) came from other sites (sputum, Skin). These comprised of 41.2% (n=21) males and58.8%(n=30) females. Age group of peak infection being (1-10) and (41-50) years. Most methicillin-resistant Staphylococcus aureus (MRSA) came from surgical/medical wards and out-patient department, but number recovered was more in special care baby unit (SCBU) and in accident/emergency unit (A/E). Oxacillin screened 66.6% (n=34) as methicillin resistant. On the other hand, cefoxitin screened 25.5% (n=13) as methicillin resistant. However, when the break point interpretative criteria were employed for both antibiotic disks, the number of isolates that resisted oxacillin(≤10mm zone diameter), increased from 66.6% (n=34) to 78.4% (n=40). Similarly the number of isolates resisting cefoxitin increased from 25.5% (n=13) to 88.2% (n=45).

2/34 DIFFERENTIATION OF HUMAN AND BOVINE TUBERCULOSIS BY NIACIN PRODUCTION AND NITRATE REDUCTION TESTES

Taysir R. Hafez and Nabila A.Alsheikh

Department of Microbiology and Immunology, Faculty of Medicine,

Al-Azhar University.

The work was carried out on 20 lymph nodes from tuberculin skin positive cattle. Tissues were homogenized using sterile tissue blender and decontaminated by using 4% sulfuric acid. In addition, 20 mycobacterium tuberculosis complex isolates (isolated by BACTEC TB system and identified by NAP test) from patients with pulmonary tuberculosis were studied. Isolates were from 18 cases with pulmonary TB and 2 cases with tuberculous lymph node. All the tests used in this study discriminate between these two variants. Differentiation of isolates was based on colonies morphology, rate of growth, pigment production, the abilities of the isolates to produce niacin or reduce nitrate into nitrites during growth, stability of catalase at 68o C for   20 minutes, Reference strains from American Type Culture Collection were included in each test as positive and negative controls.18 out of 20 bovine lymph nodes gave positive cultures (90%). All human and bovine isolates were subcultured on fresh L.J. slopes (glycerinated and pyruvated) and the resultant growth was checked for purity and subcultured on Middlebrook 7H9 liquid media. The results show that all human and bovine isolates were slow growers and all were non-pigmented. 90% 0f the human isolates were niacin positive and 90% were nitrate positive. All the bovine isolates were niacin negative while one isolate was niacin positive. This isolate was nitrate negative. The results of nitrate reduction test shows that all the bovine isolates were negative except one isolate (5%) was nitrate positive, and this isolate was niacin negative.

3/34 OPTIMIZATION OF GROWTH CONDITIONS FOR PROPER AGROCIN PRODUCTION BY RHIZOBIUM RADIOBACTER

Lobna A. Moussa and Ahmed E. Mohy

Department of Soil Microbiology – Soils, Water and Environmental Research Institute – Agricultural Research Center

A chemically defined medium was developed to support the growth of domestic isolate of Rhizobium radiobacter (HQ 395610-Egypt) and its production of agrocin. Various supplements were investigated for their effect on production of agrocin 84 using the method of well-diffusion assay against Agrobacterium tumefaciens. D-fructose as carbon source was found to be a better substrate for agrocin production compared to the other sugars and sugar alcohols tested, while monobasic ammonium phosphate was the best nitrogen source than other organic and inorganic ones. On the other hand, scaling up C/N ratio to 1:16 under pH 5.5 at 35˚C incubation temperature maximized the production after 12 hr. In the fermentor, scaling up to 1L maximized the results nearly twice at agitation speed of 200 rpm and airflow of 1 Lpm. Agrocin fragments were successfully separated, partially purified and well located by UV spectrum at 254 nm.

 

 

4/34 HEALTH CARE–ASSOCIATED INFECTIONS WITH ACINETOBACTER SPP. IN INTENSIVE CARE UNITS AT AIN SHAMS UNIVERSITY HOSPITALS

Fatma M. Saad, Amany T. Abdel Rahman, Shereen E. Taha and

Sara M. Abd El-Hakam*

Medical Microbiology & Immunology Department and **Tropical Medicine Department, Faculty of Medicine, Ain Shams University

Acinetobacter species are ubiquitous aerobic Gram negative coccobacilli that are now increasingly responsible for a large number of nosocomial infections. The rising incidence of Acinetobacter infection in the intensive care unit (ICU) causes a great concern to all clinicians worldwide due to their extraordinary ability to develop resistance to multiple classes of antibiotics. Acinetobacter can infect virtually any body site, particularly the lower respiratory tract, the bloodstream and the urinary tract. Infection is mainly related to the inappropriate or previous use of antibiotics and the increasing use of invasive devices in the ICU. This work aimed to study the role of Acinetobacter species in infections in Intensive Care Units at Ain Shams University Hospitals and study their antimicrobial susceptibility. The study included fifty inpatients admitted at Ain Shams University Hospitals at ICUs during the period from January to July 2011. From these patients 23 urine specimens, 19 respiratory specimens, 5 blood specimens and 3 pus specimens were collected and cultured aerobically. The isolated microorganisms were identified by conventional microbiological methods. Antimicrobial susceptibility test was carried to bacterial isolates using the disc diffusion method. Five isolates of Acinetobacter species were obtained from a total of 60 isolates grown from all clinical specimens. Three of them were obtained from respiratory tract infections, one from urinary tract infections and one from wound infections. All isolated Acinetobacter species were resistant to ampicillin, pipracillin, cefazolin and ceftazidime, while 80% were resistant to both amoxicillin-clavulanic and azetronam and 60% were resistant to bothtrimethoprim-sulfamethoxazole and ciprofloxacin. Forty percent were resistant to gentamicin, 20% to both pipracillin-tazobactam and amikacin while all were sensitive to both meropenem and doxycycline. The study concluded that Acinetobacter species have a role in hospital acquired infections and were more implicated in respiratory infections. Local surveillance study is important in deciding the most adequate therapy for Acinetobacter infections.

5/34 E. COLI O 157 AND SHIGELLA DYSENTERIAE TYPE 1 (SHIGELLA SHIGA) IN HEMORRHAGIC DIARRHEA SYNDROME

Wafaa A. El Shafei, Mosaad Abdel Fatah Morgan, Amal M. Saeedand
Fotouh A.M. Elsharkawy

Microbiology & Immunology Department, Faculty of Medicine Benha University

Enterohemorrhagic Escherichia coli (EHEC) is one of diarrheagenic E.coli that produce Shiga toxins (Stx) causing diarrhea, Hemorrhagic Colitis (HC), and Hemolytic Uremic Syndrome (HUS).E. coli O157:H7 is the most common and the one that can be identified in the clinical specimens of the EHEC species. Shigella dysenteriae type 1 (Shigella shiga) produces shiga toxin, identical to Stx-1, thus causes HC and HUS. The aim of this work was to detect the role of Shigella shiga and E. coli O157 as causative agents of hemorrhagic diarrhea, and detecting cytopathic effect of verotoxin producing E. coli   O157 on tissue culture. 70 stool samples collected from patients with bloody diarrhea were investigated for the presence of E. coli O157 and Shigella shiga by culture methods on Sorbitol MacConkey agar and ChromIDTM O157:H7) and latex agglutination test. Cytotoxic effect to Vero cells of isolated E. coli O157 was also determined. This study found that (10%) of isolated organisms was E.coli O157, Shigella shiga also represent the same percent, while E.coli O111 and E.coli O26 represent (8.6%, 5.6%) respectively. About 85.7 % of isolated E.coli O157 showed a reasonable toxicity to Vero cells post treatment with bacterial toxin by tetrazolium-based colorimetric assay (MTT assay). E. coli O157 and Shigella shiga play major role in the etiology of hemorrhagic diarrhea. In addition, stool culture on Sorbitol MacConkey agar followed by ChromIDTM O157:H7agar is a simple and reliable method for E. coli O157 detection.

6/34 DETECTION OF ESCHERICHIA COLI O157:H7 AND SALMONELLA SPP. IN SOME SAUDI FOODS

El-Safey Mohamed El-Safey and Khaled Mohamed Al-Jaralah*

Faculty of Science, Al-Azhar University, Assiut 71511, Egypt.

* College of Applied Medical Science, Majmah University, AlMajmmah 66, KSA

A survey was done in Almajmaah, KSA, for detection of Salmonella, and Escherichia coli O157:H7, in some Saudi foods. A total 220 samples, 100 ready-to-eat Saudi foods samples include; KABSA MANDI, KABSA MATHBI, MEFATTAH, SHAKSHOKAH, chicken SHAWERMA, and 120 Saudi foods samples include; camel milk, cow milk, chicken, lamb meat, camel meat, cow meat, obtained from restaurants supermarket and local markets were screened. E. coli O157:H7 isolates was detected in one out of 20 (5 %) cow milk, 2 of 20 (10 %) SHAWERMA and one out of 20 (5 %) chickensamples.On the other hand, Salmonella spp. were detected in 3 out of of 20 (15 %) chicken samples, 2 of 20 (10 %) lamb meat samples and 4 of 20 (20 %) chicken SHAWERMA samples. and 2 of 20 (10 %) SHAKSHOKAH samples; 1 of 20 (5 %) camel meat samples. and 3 of 20 (15 %) cow milk sample. The results indicated that, optimal temperature for growth of both E. coli O157:H7 and Salmonella spp. isolates were 35 °C the increase or decrease of temperature indicates decrease in growth of all isolates. The optimal pH values for growth of E. coli O157:H7 and Salmonella spp. isolates was at 7.0 and the increase or decrease of pH values indicates decrease in growth of all isolates. Antibiotic susceptibility patterns indicated that Escherichia coli O157:H7 isolates (M3) was resistant to bacitracin and Escherichia coli O157:H7 isolates (M4) resistant to penicillin G. On the other hand, Salmonella spp. M1 was resistant to bacitracin and Sulphamethoxozole/Trimethoprim 19:1, Salmonella spp. M2 & M11 were found resistant to sulfamethoxazole/Trimethoprim 19:1, Salmonella spp. M13 was resistant to bacitracin and Salmonella spp. M14 was resistant to cefazolin. This study emphasized that, the presence of some pathogenic bacteria in chicken SHAWERMA and chicken meat is of concern due to their potential to cause human infections, so the current control measures on animal origin foods should be improved.

7/34 INCIDENCE OF SALMONELLA HEIDELBERG IN SOME EGYPTIAN FOODS

El-Safey Mohamed El-Safey

Botany and Microbiology Department, Faculty of Science, Al-Azhar University, EGYPT (Now, on Secondment to College of Applied Medical Science, Majmaah University, Al-Majmaah 11952, P.O. 1816, KSA),

A total of two hundred samples of Egyptian foods including chicken, beef, milk, Kushary and Sogok (sausage) were obtained from local markets and super markets. The foods were examined to detected Salmonella heidelberg. As a results, Salmonella heidelberg were detected in 6 of 40 (15%) chicken; 2 of 40 (5%) beef; 1 of 40 (2.5%) milk; 1of 40 (2.5%) Kushary and 4 of 40 (10%) of Sogok. The effects of temperature, pH, and antibiotics on growth Salmonella heidelberg were studied. The results indicated that, 35 ºC was the optimum temperature and 6.8 was the optimum pH for Salmonella heidelberg growth. Antibiotic susceptibility patterns indicated that, 4 out of 14 (28.5%) of Salmonella heidelberg isolates (E5, E7, E12 and E13) were resistant to cefazolin, bacitracin, ceftazidime and sulphamethoxazole/ trimethoprim 19:1 respectively. This study emphasized that, the presence of Salmonella heidelberg in some Egyptian foods under investigation chicken, beef, milk, Kushary and Sogok (sausage) is of concern due to their potential to cause human infections, and its resistant to some antibiotics, so the current control measures on animal origin foods should be improved.

8/34 PHENOTYPIC AND GENOTYPIC METHOD FOR THE DETECTION OF MEXEF OPR-N EFFLUX PUMP IN PSEUDOMONAS AERUGINOSA

Eglal A. El-Sherbini, Dalia E. Metwally, Gihan A. El-Batouti* and

IngyI. El-Soudany*

Department of Microbiology, Medical Research Institute, University of Alexandria.

*Department of Microbiology, Faculty of Pharmacy, University of Pharos.

P. aeruginosa is a leading pathogen that causes health care associated infections. It has acquired multiple mechanisms of resistance against all available anti-pseudomonal agents. The efflux-mediated resistance mechanisms confer a moderate level of resistance and are often multidrug resistant. Its clinical impact could be important, because it may make antibiotics inefficient in infected sites, and it confers cross-resistance to unrelated antibiotic classes. In this studya combined phenotypic and genotypic approach were used for the diagnosis of resistance mediated by MexEF-OprN efflux pump among clinical and environmental isolates of P. aeruginosa. Phenotypic detection used MIC measurements of levofloxacin (LVX) with and without Phe-Arg-β-naphthylamide. Genotypic detection was made by reverse transcription polymerase chain reaction to detect the expression of the MexEF-OprN gene. All the 50 LVX resistant P. aeruginosa isolates had cross resistance to the Floroquinolones (FQ) group of antibiotics included in the study (norfoxacin, ciprofloxacin and ofloxacin). Among the antibiotics tested Imipenem (IPM) was the most active against LVX resistantP. aeruginosa (42%) followed by Cefepime (FEP) (20%), and the other antibiotics activity ranged from 0% to less than 20%. Twenty one isolates showed complete convergnce (20 P+ G+ and 1 P- G-). Partial conversion was observed in 3 strains (P- G+) and divergence was observed in 3 strains (P+ G-). Inhibition of efflux systems with broad-spectrum inhibitors would seem to be a prudent approach to combat and/or prevent FQs resistance or even multidrug resistance.

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