Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Dalia A. Hamza is active.

Publication


Featured researches published by Dalia A. Hamza.


Journal of global antimicrobial resistance | 2016

Carbapenemase-producing Klebsiella pneumoniae in broiler poultry farming in Egypt

Eman Hamza; Sohad M. Dorgham; Dalia A. Hamza

This study investigated the occurrence of carbapenem-resistant Klebsiella pneumoniae strains in broiler chickens, drinking water and humans working in contact with chickens and identified the carbapenem resistance determinants among isolates from different sources. Internal organs and droppings were collected from 100 broilers with signs of respiratory disease at five broiler farms in Egypt. Additionally, 20 drinking water samples and 49 faecal samples from workers and veterinarians working at these farms were included. Following culture on MacConkey agar, suspected K. pneumoniae colonies were identified by phenotypic testing. Susceptibility to carbapenems was tested in confirmed K. pneumoniae isolates by disk diffusion. Carbapenem-resistant isolates were subjected to PCR for detection of carbapenemase-encoding genes (blaKPC, blaOXA-48 and blaNDM). K. pneumoniae was isolated from 35% of broilers and 25% of water samples. Of the 35 poultry isolates, 15 were carbapenem-resistant; all of them were blaNDM-positive, including 11 isolates harbouring blaKPC, blaOXA-48 and blaNDM and 4 containing either blaKPC and blaNDM (n=3) or blaOXA-48 and blaNDM (n=1). Similarly, three of five K. pneumoniae isolates from drinking water were positive for blaKPC and blaNDM (n=1) or for all three genes (n=2). Interestingly, 56% of K. pneumoniae from humans displayed carbapenem resistance; all of them were positive for the three carbapenemase genes. Carbapenemase-producing K. pneumoniae occurred at relatively high frequency among broilers, drinking water and workers at poultry farms in Egypt. Additional work is needed to confirm transmission between poultry and humans and to elucidate the direction and mechanism of transmission.


International Journal of Microbiology | 2016

Eucalyptus Tree: A Potential Source of Cryptococcus neoformans in Egyptian Environment

Dalia A. Hamza; Rehab Elhelw; M. Refai

In Egypt, the River Red Gum (Eucalyptus camaldulensis) is a well-known tree and is highly appreciated by the rural and urban dwellers. The role of Eucalyptus trees in the ecology of Cryptococcus neoformans is documented worldwide. The aim of this survey was to show the prevalence of C. neoformans during the flowering season of E. camaldulensis at the Delta region in Egypt. Three hundred and eleven samples out of two hundred Eucalyptus trees, including leaves, flowers, and woody trunks, were collected from four governorates in the Delta region. Thirteen isolates of C. neoformans were recovered from Eucalyptus tree samples (4.2%). Molecular identification of C. neoformans was done by capsular gene specific primer CAP64 and serotype identification was done depending on LAC1 gene. This study represents an update on the ecology of C. neoformans associated with Eucalyptus tree in Egyptian environment.


Acta Tropica | 2017

The burden of Coxiella burnetii among aborted dairy animals in Egypt and its public health implications

Khaled A. Abdel-Moein; Dalia A. Hamza

Q fever is a zoonotic disease of mounting public health implications. Dairy animals are major reservoir for such disease whereas abortion is the main clinical outcome. The current study was conducted to investigate the burden of C. burnetii abortions among dairy animals in Egypt to provide more knowledge for better control of such disease. For this purpose, placental cotyledons and vaginal discharges from 108 aborted dairy animals (27 sheep, 29 goats, 26 cattle, 26 buffaloes) were examined for the presence of C. burnetii by nested PCR. Serum samples from 58 human contacts were examined for the presence of C. burnetii IgG antibodies using ELISA. Out of the 108 examined animals only one goat yielded positive result in both placental tissue and vaginal discharges with an overall prevalence 0.9% while that among goats is 3.4%. Moreover, the seroprevalence of C. burnetii IgG antibodies among the examined individuals was 19% whereas the prevalence in farmers is significantly higher than that among veterinarians and veterinary assistants. In conclusion, C. burnetii may play a role in dairy goat abortions rather than other dairy animals in Egypt while its public health implications cannot be ruled out.


Annals of Clinical Microbiology and Antimicrobials | 2017

Extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa in camel in Egypt: potential human hazard

Dalia A. Hamza; Rehab Elhelw; Sohad M. Dorgham

BackgroundThe 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.MethodsIn 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 blaPER-1, blaCTX-M, blaSHV, and blaTEM.ResultsPseudomonas 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 (blaPER-1 28.5%, blaCTX-M 38%, blaSHV 33.3% and blaTEM 23.8%).ConclusionsThis 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.


Microbial Pathogenesis | 2018

Genotyping and antimicrobial resistance patterns of Helicobacter pylori in human and dogs associated with A2142G and A2143G point mutations in clarithromycin resistance

Dalia A. Hamza; Rehab Elhelw; Eman A. Ragab

BACKGROUND Routes of transmission of Helicobacter pylori a class I carcinogen bacterium and the roles of animals have not been yet well determined. This study was carried out to investigate H. pylori phenotypically and genotypically in human and dogs to determine the antibiotic resistance patterns. As eradication therapy depends mainly on clarithromycin we evaluated 23S rRNA gene mutations associated with its resistance. RESULTS A total of 150 human stool samples and 60 canine gastric biopsies were examined by nested PCR for the presence of H. pylori, 60% and 76.6% were positive respectively. Only 20 (22.2%) and 41 (89.1%) isolates were successfully cultured from human and canine samples respectively. Genotyping revealed a total of cagA+vacA+ combinations 76.6% (69/90) and 65.2% (30/46) in human and dogs, respectively. Allelic diversity in vacA gene was obviously observed, while cagA-vacA+ combinations were 23.3% (21/90) and 34.7% (16/46) in human and dogs, respectively. The antimicrobial susceptibility patterns of human exhibited the highest levels of resistance against Clarithromycin (60%), Trimethoprim (55%), metronidazole (45%), amoxicillin (45%) and cefsulodin (60%) antibiotics and comparatively lower for spiramycin (10%) and tetracycline (15%). Dogs strains showed the highest levels of resistance against Clarithromycin (53.6%), metronidazole (51.2%) and erythromycin (43.9%) antibiotics, on the other hand, the percent of resistant canine strains were comparatively lower for spiramycin (9.7%). Single point mutation of A2143G was detected as 25% (3/12), 18.1% (4/22) in human and dogs respectively. Single point mutation of A2142G was detected as 16.6% (2/12), 13.6% (3/22) in human and dogs, respectively. While dual mutations of both A2142G and A2143G were detected as 50% (6/12), 40.9% (9/22) in human and dogs, respectively. CONCLUSION occurrence of elevated rates of A2142G and A2143G point mutations in clarithromycin resistant H. pylori isolates from human and dogs causing failure in treatment and eradication of the pathogen. The roles of animals need attention and further investigations.


Pathogens and Global Health | 2016

Occurrence of human pathogenic Clostridium botulinum among healthy dairy animals: an emerging public health hazard

Khaled A. Abdel-Moein; Dalia A. Hamza

The current study was conducted to investigate the occurrence of human pathogenic Clostridium botulinum in the feces of dairy animals. Fecal samples were collected from 203 apparently healthy dairy animals (50 cattle, 50 buffaloes, 52 sheep, 51 goats). Samples were cultured to recover C. botulinum while human pathogenic C. botulinum strains were identified after screening of all C. botulinum isolates for the presence of genes that encode toxins type A, B, E, F. The overall prevalence of C. botulinum was 18.7% whereas human pathogenic C. botulinum strains (only type A) were isolated from six animals at the rates of 2, 2, 5.8, and 2% for cattle, buffaloes, sheep, and goats, respectively. High fecal carriage rates of C. botulinum among apparently healthy dairy animals especially type A alarm both veterinary and public health communities for a potential role which may be played by dairy animals in the epidemiology of such pathogen.


Acta Parasitologica | 2016

Norway rat (Rattus norvegicus) as a potential reservoir for Echinococcus granulosus: A public health implication.

Khaled A. Abdel-Moein; Dalia A. Hamza

Cystic hydatidosis is a re-emerging parasitic zoonosis with worldwide distribution. The current study was carried out to investigate the possible role of rats in the epidemiology of such disease in urban and suburban areas. For this purpose, a total of 50 feral Norway rats (Rattus norvegicus) were collected from urban and suburban settings, Cairo, Egypt. Rats were examined to be infected with cystic hydatidosis through serological examination by IHA test as well as post-mortem examination of internal organs, histopathological or molecular identification of the collected cysts. Moreover, 42 persons inhabiting suburban areas were tested for cystic hydatidosis by IHA. The overall seroprevalence rates of cystic hydatidosis in the examined rats and persons were 36% and 11.9% respectively. Cysts from 3 rats were identified as E. granulosus hydatid cysts (one via histopathological examination while the others by molecular technique and genotyped as G6 strain). The results of the current study highlight the possible role of Norway rat in the epidemiological cycle of E. granulosus especially in urban and suburban settings.


Scientific Reports | 2018

Occurrence of cagA+ vacA s1a m1 i1 Helicobacter pylori in farm animals in Egypt and ability to survive in experimentally contaminated UHT milk

Dalia A. Hamza; Rehab Elhelw; Eman Hamza

Cases of human gastric cancer due to Helicobacter pylori have been reported worldwide and animals might act as a reservoir of infection in certain circumstances. The recent few decades showed a rapid decline in the incidence of gastric cancer, which was mainly due to the decrease in H. pylori infection. The aims of the present study were to determine the prevalence of H. pylori among livestock and investigate whether the animal isolates can be transmitted through contaminated milk causing gastric infection. Feces and milk samples were collected from apparently healthy cows, buffaloes, and sheep, and were examined by nested PCR and genotyping. The PCR positive samples were further subjected to bacterial culture followed by partial 16s sequencing of the isolates. Twenty-nine percent of the animals showed the presence of H. pylori, mainly the virulent cagA+vacA+s1a m1 i1 genotype, which is known to be associated with serious diseases in humans. The spiral viable culturable form (SVCF) of this strain was inoculated into UHT (ultra-high temperature) milk and remained viable for up to 10 days at 4 °C. Increasing period of storage and or temperature led to a decrease in the number of the SVCF and occurrence of the coccoid viable non-culturable form (CVNCF). The infectivity of the survived forms was determined by feeding healthy groups of laboratory mice with the contaminated UHT milk containing SVCF or CVNCF for 40 days. The gastric mucosa of the two mice groups showed similar levels of H. pylori load. This highlights that H. pylori can persist in contaminated milk by entering a non-culturable state, which can induce gastric infection.


Journal of Veterinary Research | 2017

Toxinotyping and antimicrobial resistance of Clostridium perfringens isolated from processed chicken meat products

Dalia A. Hamza; Sohad M. Dorgham; Ashraf Hakim

Abstract Introduction: The toxinotyping and antimicrobial susceptibility of Clostridium perfringens strains isolated from processed chicken meat were determined. Material and Methods: Two hundred processed chicken meat samples from luncheon meats, nuggets, burgers, and sausages were screened for Clostridium perfringens by multiplex PCR assay for the presence of alpha (cpa), beta (cpb), epsilon (etx), iota (ia), and enterotoxin toxin (cpe) genes. The C. perfringens isolates were examined in vitro against eight antibiotics (streptomycin, amoxicillin, ampicillin, ciprofloxacin, lincomycin, cefotaxime, rifampicin, and trimethoprim-sulfamethoxazole) Results: An overall of 32 C. perfringens strains (16%) were isolated from 200 processed chicken meat samples tested. The prevalence of C. perfringens was significantly dependent on the type of toxin genes detected (P = 0.0), being the highest in sausages (32%), followed by luncheon meats (24%), burgers (6%), and nuggets (2%). C. perfringens type A was the most frequently present toxinotype (24/32; 75%), followed by type D (21.9 %) and type E (3.1%). Of the 32 C. perfringens strains tested, only 9 (28%) were enterotoxin gene carriers, with most representing type A (n = 6). C. perfringens strains differed in their resistance/susceptibility to commonly used antibiotics. Most of the strains tested were sensitive to ampicillin (97%) and amoxicillin (94%), with 100% of the strains being resistant to streptomycin and lincomycin. It is noteworthy that the nine isolates with enterotoxigenic potential had a higher resistance than the non-enterotoxigenic ones. Conclusion: The considerably high C. perfringens isolation rates from processed chicken meat samples and resistance to some of the commonly used antibiotics indicate a potential public health risk. Recent information about the isolation of enterotoxigenic C. perfringens type E from chicken sausage has been reported.


Asian Pacific Journal of Tropical Disease | 2016

Occurrence of human hepatitis E virus in Norway rats: A zoonotic potential with great public health implications

Nahed H. Ghoneim; Khaled A. Abdel-Moein; Dalia A. Hamza; Naglaa Mohamed Hagag

Abstract Objective To investigate the occurrence of human hepatitis E virus genotype I among sheep and rats as well as seroprevalence of hepatitis E virus immunoglobulin G (IgG) antibodies among people live in rural settings. Methods Fecal samples were collected from 43 Norway rats and 30 sheep. All fecal samples were examined for the presence of human hepatitis E virus genotype I through direct detection using RT-PCR. In addition, serum samples collected from 90 apparently healthy persons live in rural settings were examined for the presence of hepatitis E virus IgG antibodies by using enzyme linked immunosorbent assay. Results Out of 73 examined animals, human hepatitis E virus genotype I was detected in five animals giving an overall prevalence 6.8% while only rats given positive results 11.6%. Furthermore, the overall seroprevalence of hepatitis E virus IgG antibodies among the examined individuals was 63.3% while the seroprevalence in adults (75.0%) was higher than that in children (34.6%). Conclusions The detection of human hepatitis E virus genotype I in the feces of Norway rats in such high prevalence highlights the possible role which may be played by such animal in the epidemiology of hepatitis E virus infections in rural settings where the virus is more prevalent among human populations.

Collaboration


Dive into the Dalia A. Hamza's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge