Dalia Hamza

Dr. Dalia Hamza

zoonoses, Faculty of Veterinary Medicine, Cairo University, Giza, Al Jīzah, Egypt
orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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1 December 2016 in Journal of Global Antimicrobial Resistance
Verified
Journal Article
Closed access
EHEman Hamza
Eman Hamza
SDSohad M. Dorgham
Sohad M. Dorgham
DHDalia Hamza
Dalia Hamza

3 December 2019 in Antimicrobial Resistance & Infection Control
Verified
Journal Article
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ZAZeinab Ahmed
Zeinab Ahmed
EEEsraa Elshafiee
Esraa Elshafiee
HKHanan S. Khalefa
Hanan S. Khalefa
MKMona Kadry
Mona Kadry
DHDalia Hamza
Dalia Hamza
Background: Antimicrobial resistance has become one of the most severe global threats to human and veterinary Medicine. colistin is an effective therapeutic agent against multi-drug-resistant pathogens. However, the discovery of transferable plasmids that confer resistance to colistin (mcr-1) has led to challenges in medical science. This study describes the role of wild birds in the harbouring and environmental spread of colistin-resistant bacteria, which could pose a potential hazard to human and animal health. Methods: In total, 140 faecal samples from wild birds (migratory and resident birds) were tested. Twenty surface water samples were collected from the area in which wild bird trapping was conducted, and 50 human stool samples were collected from individuals residing near the surface water sources and farm buildings. Isolation and identification of Enterobacteriaceae and Pseudomonas aeruginosa from the different samples were performed using conventional culture techniques and biochemical identification. PCR amplification of the mcr genes was performed in all positive isolates. Sequencing of mcr-1 genes from three randomly selected E. coli carrying mcr-1 isolates; wild birds, water and humans was performed. Result: The bacteriological examination of the samples showing isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and P. aeruginosa. The results of multiplex PCR of the mcr genes revealed that E. coli was the most prevalent gram-negative bacterium harbouring the mcr genes, whereas a low prevalence was observed for K. pneumoniae. The prevalence of mcr-1 in resident birds, migratory birds, water sources and humans were 10.4, 20,16.6 and 9.6% while the prevalence of mcr-2 were 1.4, 3.6, 11.1 and 9.6%, respectively. Sequencing of the mcr-1 gene from the three E. coli carrying mcr-1 isolates indicated a possible correlation between the wild bird and surface water isolates. Conclusion: The detection of mcr-1-positive bacteria in wild birds in Egypt indicates the possible environmental dissemination of this gene through bird activity. The impact of the interaction between domestic and wild animals on public health cannot be overlooked.

5 August 2019 in Antimicrobial Resistance & Infection Control
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Journal Article
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KAKhaled Al-Amery
Khaled Al-Amery
MEMahmoud Elhariri
Mahmoud Elhariri
AEAlaa Elsayed
Alaa Elsayed
GEGihan El-Moghazy
Gihan El-Moghazy
RERehab Elhelw
Rehab Elhelw
DHDalia Hamza
Dalia Hamza
The emergence of vancomycin-resistant Staphylococcus aureus (VRSA) represents a challenge for the treatment of staphylococcal infections in both human and animals worldwide. Although VRSA has been detected in several animal species worldwide, data on the bacterial prevalence in dromedary camels and workers in camel slaughterhouses are scarce. We investigated meat samples from 200 dromedary camel carcasses from three different abattoirs that were being prepared to be sent to the markets. Twenty hand swabs were voluntarily collected from the workers in the same abattoirs. Isolation and identification of the bacterial specimens from the samples were performed using conventional cultural techniques and biochemical identification and were confirmed by PCR amplification of the nuc gene. Antimicrobial susceptibility against nine antimicrobial agents commonly used in human and camels was tested using the disc diffusion method, and genetic analysis was performed by evaluating the mecA gene in phenotypically oxacillin (OXA)- and cefoxitin (FOX)-resistant isolates. The resistance of S. aureus to vancomycin (VAN) was tested by broth microdilution and confirmed by PCR targeting the vanA and vanB genes. The vanA and vanB genes were sequenced. S. aureus was detected in both camel meat (29/200, 14.5%) and in abattoir workers (11/20, 55%). Of the collected samples, 27% (8/29, camel) and 54% (6/11, human) were identified as VRSA. All VRSA isolates carried both the vanA and vanB genes. Additionally, all VRSA isolates were also classified as methicillin-resistant S. aureus (MRSA). The vanA amplicons of the isolates from human and camel meat were homologous and clustered with a Chinese reference isolate sequence. This study demonstrated that VRSA is present in camel abattoirs in Egypt. Zoonotic transmission between animals and human is probable and reflects both a public health threat and a food safety concern.

2 January 2019 in International Journal of Veterinary Science and Medicine
Verified
Journal Article
Open access
KFKarima M Fahim
Karima M Fahim
EIElshaimaa Ismael
Elshaimaa Ismael
HKHanan S Khalefa
Hanan S Khalefa
HFHeba S Farag
Heba S Farag
DHDalia Hamza
Dalia Hamza
The study was conducted to estimate the prevalence of Escherichia coli (E. coli) in sub-clinically mastitic (SCM) animals, and in wild and migratory birds which may act as reservoir disseminating such pathogen. Farm hygiene, management and milking procedures were listed through a questionnaire. Thirty lactating cows and 15 lactating buffaloes from five small-scale dairy farms were randomly selected and screened for subclinical mastitis (SCM) using California Mastitis Test (CMT) and somatic cell count (SCC). In addition, 80 teat skin swabs, 5 drinking water samples and 38 wild and migratory bird faecal matter were also collected. All samples were processed for E. coli isolation by culturing on Levine’s Eosin Methylene Blue (L-EMB) agar, followed by purification and biochemical identification. Positive samples were subjected to molecular identification and serotyping. In addition, the presence of extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing E. coli have been reported by antimicrobial sensitivity testing. Escherichia coli were isolated from 7.7%, 50% and 50% of the positive CMT cows’ quarters, cows’ composite and buffaloes’ composite milk samples, respectively. In addition, 14% of cows’ teats, 20% of water samples, 70% of faecal matter from wild bird, and 33.3% of faecal matter from migratory waterfowls were carrying E. coli. Serotyping, antibiotic-resistant pattern and phylogenetic analysis have pointed the bearable implication of milking hygiene and wild birds in disseminating E. coli strains causing intramammary infections.

19 May 2020 in Antimicrobial Resistance & Infection Control
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Journal Article
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DHDalia Hamza
Dalia Hamza
SDSohad Dorgham
Sohad Dorgham
EIElshaimaa Ismael
Elshaimaa Ismael
SESherein Ismail Abd El-Moez
Sherein Ismail Abd El-Moez
MEMahmoud Elhariri
Mahmoud Elhariri
EHEman Hamza
Eman Hamza
Background: Epidemiological studies suggested that determinants for antibiotic resistance have originated in aquaculture. Recently, the integrated agriculture-aquaculture system has been implemented, where fish are raised in ponds that receive agriculture drainage water. The present study aims to investigate the occurrence of β-lactamase and carbapenemase-producing Enterobacteriaceae in the integrated agriculture-aquaculture and the consequent public health implication. Methods: Samples were collected from fish, fishpond water inlets, tap water, outlet water, and workers at sites of integrated agriculture-aquacultures. Samples were also taken from inhabitants of the aquaculture surrounding areas. All samples were cultured on MacConkey agar, the Enterobacteriaceae isolates were tested for susceptibility to cephalosporins and carbapenems, and screened for blaCTX-M-15, blaSHV, blaOXA-1, blaTEM, blaPER-1, blaKPC, blaOXA-48, and blaNDM. Strains having similar resistance phenotype and genotype were examined for the presence of Incompatible (Inc) plasmids. Results: A major proportion of the Enterobacteriaceae isolates were resistant to cephalosporins and carbapenems. Among the 66 isolates from fish, 34 were resistant to both cephalosporin and carbapenem groups, 26 to carbapenems alone, and 4 to cephalosporins alone. Of the 15 isolates from fishpond water inlets, 8 showed resistance to both groups, 1 to carbapenems alone, and 5 to cephalosporins alone. Out of the 33 isolates from tap water, 17 were resistant to both groups, and 16 to cephalosporins alone. Similarly, of the 16 outlet water isolates, 10 were resistant to both groups, and 6 to cephalosporins alone. Furthermore, of the 30 examined workers, 15 carried Enterobacteriaceae resistant strains, 10 to both groups, and 5 to cephalosporins alone. Similar strains were isolated from the inhabitants of the aquaculture surrounding areas. Irrespective of source of samples, strains resistant to all examined antibiotics, carried predominantly the carbapenemase gene blaKPC either alone or with the β-lactamase genes (blaCTX-M-15, blaSHV, blaTEM, and blaPER-1). The isolates from fish, water, and workers harboured a wide-range of multi-drug-resistance Inc. plasmids, which were similar among all isolates. Conclusion: The present findings suggest transmission of the resistance genes among Enterobacteriaceae strains from different sources. This reiterates the need for control strategies that focus on humans, animals, water, and sewage systems to solve the antibiotic resistance problem.

31 March 2017 in Annals of Clinical Microbiology and Antimicrobials
Verified
Journal Article
Open access
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MEMahmoud Elhariri
Mahmoud Elhariri
DHDalia Hamza
Dalia Hamza
RERehab Elhelw
Rehab Elhelw
SDSohad M. Dorgham
Sohad M. Dorgham
The rapid increase of extended-spectrum beta-lactamase (ESBL) producing bacteria are a potential health hazard. Development of antimicrobial resistance in animal pathogens has serious implications for human health, especially when such strains could be transmitted to human. In this study, the antimicrobial resistance due to ESBL producing Pseudomonas aeruginosa in the camel meat was investigated. In this study meat samples from 200 healthy camels at two major abattoirs in Egypt (Cairo and Giza) were collected. Following culture on cetrimide agar, suspected P. aeruginosa colonies were confirmed with a Vitek 2 system (bioMe´rieux). P. aeruginosa isolates were phenotypically identified as ESBL by double disk synergy test. Additionally antimicrobial susceptibility testing of ESBL producing P. aeruginosa isolates were done against 11 antimicrobial drugs and carried out by disk diffusion method. The ESBL genotypes were determined by polymerase chain reaction according to the presence of the bla PER-1, bla CTX-M, bla SHV, and bla TEM. Pseudomonas aeruginosa was isolated from 45 camel meat sample (22.5%). The total percentage of ESBL producing P. aeruginosa was 45% (21/45) from camel meat isolates. Antibiogram results revealed the highest resistance was for c, ceftriaxone and rifampicin followed by cefepime and aztreonam. The prevalence rates of β-lactamase genes were recorded (bla PER-1 28.5%, bla CTX-M 38%, bla SHV 33.3% and bla TEM 23.8%). This study illustrates the presence of high rates of ESBL-P. aeruginosa in camels that represents an increasing alarming for the risk of transmission to human and opens the door for current and future antibiotics therapy failure. Livestock associated ESBL-P. aeruginosa is a growing disaster, therefore, attention has to be fully given to livestock associated ESBL-bacteria which try to find its way to human beings.