Aalaa Saad

Dr. Aalaa Saad

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Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 November 2016 in Frontiers in Microbiology
Verified
Journal Article
Open access
KOKamelia Osman
Kamelia Osman
JBJihan Badr
Jihan Badr
KAKhalid S. Al-Maary
Khalid S. Al-Maary
IMIhab M. I. Moussa
Ihab M. I. Moussa
AHAshgan M. Hessain
Ashgan M. Hessain
ASAalaa Saad
Aalaa Saad
The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during one year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim and vancomycin) and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius and S. lentus). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides and streptogramin B (MLS(B)) in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance-determining-regions, the identification of MRSA and MR-CNS from retail chicken meat in Egypt. In addition, these isolates might indicate the promulgation of methicillin, oxacillin and vancomycin resistance in the community and imply food safety hazards.


29 February 2016 in Frontiers in Microbiology
Verified
Journal Article
Open access
PDF file
KOKamelia Osman
Kamelia Osman
AAAziza M. Amer
Aziza M. Amer
JBJihan M. Badr
Jihan M. Badr
NHNashwa M. Helmy
Nashwa M. Helmy
RERehab A. Elhelw
Rehab A. Elhelw
ASAalaa Saad
Aalaa Saad
Methicillin-resistant Staphylococcus aureus (MRSA) have been found in various farm animal species throughout the world. Yet, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible non-S. aureus (MS-NSA) and methicillin-resistant non-S. aureus (MR-NSA) were not investigated. Therefore, we persued to determine the diversity in their phenotypic virulence assay, phenotypic antimicrobial resistance profile and molecular characterisation in one of the food chains in Egypt. Samples were collected during 2013 from beef meat at retail. Twenty seven isolates comprising five species (S. hyicus, S. aureus, S. schleiferi subsp. coagulans, S. intermedius and S. lentus) were characterized for their antibiotic resistance phenotypic profile and antibiotic resistance genes (mecA, cfr, gyrA, gyrB and grlA). Out of the 27 Staphylococcus isolates only one isolate was resistant to the 12 antibiotics representing nine classes. Raw beef meat sold across the Great Cairo zone, contains 66.7% of MRS, with highest prevalence was reported in S. aureus (66.7%), while the MRS non-S. aureus strains constituted 66.7% from which S. hyicus (60%), S. intermedius (33.3%), S. schleiferi subsp. coagulans (100%) and S. lentus (100%) were MRS. Seven S. aureus, six S. hyicus, four S. schleiferi subsp. coagulans, three S. intermedius and one S. lentus isolates although being resistant to oxacillin yet, 11/27 (40.7%) carried the mecA gene. At the same time, the cfr gene was present in 2 of the nine S. aureus isolates, and totally undetectable in S. hyicus, S. schleiferi subsp. coagulans, S. intermedius and S. lentus. Although global researches largely focused into MRSA and MR-NSA in animals on pigs, the analysis of our results stipulates that buffaloes and cattle could be MRSA dispersers and that this theme is not specific to pigs. Detection of MSSA virulence determinants is a must, as although oxacillin resistance may be absent yet, the MSSA may carry the virulence determinants which could be a source of perilous S. aureus for the human community.

1 May 2015 in Foodborne Pathogens and Disease
Verified
Journal Article
Closed access
KOKamelia M. Osman
Kamelia M. Osman
AAAziza M. Amer
Aziza M. Amer
JBJihan M. Badr
Jihan M. Badr
ASAalaa Saad
Aalaa Saad
Coagulase-positive (CPS) and coagulase-negative (CNS) staphylococci cause staphylococcal food poisoning. Recently, CPS and CNS have received increasing attention due to their potential role in the dissemination of antibiotic resistance markers. The present study aimed to evaluate CPS and CNS species distribution and their antibiotic resistance profile isolated from chicken and beef meat. Fifty fresh, uncooked chicken parts and 50 beef meat cuts (local n =27; imported n =23) were used. One hundred staphylococcal isolates belonging to 11 species were isolated and identified from chicken ( n =50) and beef ( n =50) raw meat samples. Staphylococcus hyicus (26/100), lugdunensis (18/100), aureus (15/100) and epidermidis (14/100) were dominant. S. aureus was 100% resistant to penicillin and sulfamethoxazole/trimethoprim. Vancomycin-resistant S. aureus showed intermediate resistance (51%), which might indicate the dissemination of vancomycin resistance in the community and imply food safety hazards. The percentage of resistance to β-lactams was variable, with the highest resistance being to penicillin (94%) and lowest to ampicillin-sulbactam (22%). Antimicrobial resistance was mainly against penicillin (94%), clindamycin (90%) and sulfamethoxazole/trimethoprim (82%). The results indicate that chicken and beef raw meat are an important source of antibiotic-resistant CPS and CNS.

1 January 2020 in Acta Tropica
Verified
Journal Article
Closed access
KOKamelia Osman
Kamelia Osman
Tara ZolnikovTara Zolnikov
Tara Zolnikov
JBJihan Badr
Jihan Badr
HNHeba Naim
Heba Naim
MHMai Hanafy
Mai Hanafy
AEAyman Elbehiry
Ayman Elbehiry

25 November 2022 in Parasitology Research
Verified
Journal Article
Open access
PDF file
HMHend M. Mohamed
Hend M. Mohamed
ASAalaa Saad
Aalaa Saad
MKMarwa M. Khalifa
Marwa M. Khalifa
SASahar Z. Abdel-Maogood
Sahar Z. Abdel-Maogood
SASalwa M. F. Awadalla
Salwa M. F. Awadalla
WMWaheed Mohamed Mousa
Waheed Mohamed Mousa
Trichomonas gallinae is a protozoan parasite that causes canker in pigeons. Squabs (young pigeons) are frequently infected with T. gallinae and can die because of the infection, while adult pigeons can act as carriers showing no clinical signs. In the present study, 50 squabs, up to 1-month-old, were purchased from pigeon markets in different regions of the Giza governorate, Egypt. Direct wet mount preparations of the oral excretions of the squabs (mouth wash) and Giemsa staining revealed that 64% (32/50) were positive for T. gallinae. Experimental infection of ten squabs with 103 T. gallinae trophozoites/ml resulted in oral lesions on the mouth, tongue, and soft palate, with the presence of yellowish-white nodules (cheese-like) in the oral cavity on the sixth day post-infection in all squabs. A subset of five samples were cultured in modified Diamond’s media, their DNA was extracted, and a portion of the ribosomal internal transcribed spacer region (ITS1/5.8S/ITS2) was amplified by polymerase chain reaction (PCR) followed by sequencing. Phylogenetic analysis of the five isolates revealed 64–91% homology with some reference isolates circulating in Egypt and related countries.