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2022
Mohammed, R., S. M. Nader, D. A. Hamza, and M. A. Sabry, "Horse: a potential source of Cryptococcus neoformans and Cryptococcus gattii in Egypt.", BMC veterinary research, vol. 18, issue 1, pp. 17, 2022. Abstract

BACKGROUND: Cryptococcosis is an opportunistic mycozoonosis of global significance in a wide variety of host species. In equines, cryptococcosis is uncommon, and sporadic cases have been reported with rhinitis, sinusitis, pneumonia, and meningitis. Cryptococcus spp. represents a potential risk for immunosuppressed and healthy persons. In Egypt, epidemiological data on cryptococcal infection in horses are limited. The current study was carried out to investigate the occurrence of Cryptococcus spp. in horses and its possible role in the epidemiology of such disease in Egypt. A total of 223 samples was collected from different localities in Egypt included 183 nasal swabs from horses, 28 nasal swabs from humans, and 12 soil samples. Bacteriological examination and the identification of Cryptococcus spp. were performed. Molecular serotyping of Cryptococcus spp. was determined by multiplex PCR using CNa-70S/A-CNb-49S/A. The virulence genes (LAC1, CAP59, and PLB1) of the identified isolates were detected by PCR. Moreover, sequencing and phylogenetic analysis of the C. gattii gene from horses, humans, and soil isolates found nearby were performed.

RESULT: The overall occurrence of Cryptococcus spp. in horses were 9.3, 25, and 10.7% in horses, the soil, and humans, respectively. Molecular serotyping of the Cryptococcus spp. isolates recovered from the nasal passages of horses proved that C. gattii (B), C. neoformans, and two hybrids between C. neoformans (A) and C. gattii (B) were identified. Meanwhile, in case of soil samples, the isolates were identified as C. gattii (B). The human isolates were serotyped as C. gattii in two isolates and C. neoformans in only one isolate. Molecular detection of some virulence genes (LAC1), (CAP59), and (PLB1) were identified in both C. gattii and C. neoformans isolates. The C. gattii gene amplicons of the isolates from horses, humans, and the soil were closely related.

CONCLUSION: This study provides the first insights into the Egyptian horse ecology of Cryptococcus species and highlights the role of horses as asymptomatic carriers in disseminating the potentially pathogenic Cryptococcus spp. It also presents the possible risk of cryptococcosis infection in humans.

Elkazzaz, M., A. Ahmed, Y. E. - E. Abo-Amer, T. Hydara, A. Haikal, D. A. E. N. Razek, W. A. Eltayb, X. Wang, T. M. Karpiński, D. Hamza, et al., "In Silico Discovery of GPCRs and GnRHRs as Novel Binding Receptors of SARS-CoV-2 Spike Protein Could Explain Neuroendocrine Disorders in COVID-19.", Vaccines, vol. 10, issue 9, 2022. Abstract

Despite the intense research work since the beginning of the pandemic, the pathogenesis of COVID-19 is not yet clearly understood. The previous mechanism of COVID-19, based on ACE2 tropism and explained through a single receptor, is insufficient to explain the pathogenesis due to the absence of angiotensin-converting enzyme 2 (ACE2) receptors in most of the affected organs. In the current study, we used the PatchDock server to run a molecular docking study of both the gonadotropin-releasing hormone receptor (GnRHR) and G-protein-coupled-receptor (GPCR) with the SARS-CoV-2 spike protein. Molecular Dynamics (MD) simulations were run to analyze the stability of the complexes using the GROMACS package. The docking results showed a high affinity between the spike protein with the GnRHR (-1424.9 kcal/mol) and GPCR (-1451.8 kcal/mol). The results of the MD simulations revealed the significant stability of the spike protein with the GnRHR and GPCR up to 100 ns. The SARS-CoV-2 spike protein had strong binding interactions with the GPCRs and GnRHRs, which are highly expressed in the brain, endocrine organs, and olfactory neurons. This study paves the way towards understanding the complex mechanism of neuroendocrine involvement and peripheral organ involvement, may explain the changing symptoms in patients due to new variants, and may lead to the discovery of new drug targets for COVID-19. In vitro studies involving genetic engineering or gene knockdown of the GPCRs and GnRHRs are needed to further investigate the role of these receptors in COVID-19 pathogenesis.

2020
Hamza, D., S. Dorgham, E. Ismael, S. I. A. El-Moez, M. Elhariri, R. Elhelw, and E. Hamza, "Emergence of β-lactamase- and carbapenemase- producing Enterobacteriaceae at integrated fish farms.", Antimicrobial resistance and infection control, vol. 9, issue 1, pp. 67, 2020. Abstract

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 bla, bla, bla, bla, bla, bla, bla, and bla. 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 bla either alone or with the β-lactamase genes (bla, bla, bla, and bla). 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.

Morsy, E. A., H. M. Salem, M. S. Khattab, D. A. Hamza, and M. M. Abuowarda, "Encephalitozoon cuniculi infection in farmed rabbits in Egypt.", Acta veterinaria Scandinavica, vol. 62, issue 1, pp. 11, 2020. Abstract

BACKGROUND: Encephalitozoon cuniculi is an important microsporidian parasite with zoonotic potential. The present study highlights the impact of encephalitozoonosis on rabbit health in Egypt. Three rabbit farms in Giza, with a total of 16,400 rabbits were investigated due to occurrence of rabbits displaying clinical signs consistent with encephalitozoonosis.

RESULTS: Clinical signs observed during a 4 months observation period in 2018 included vestibular disease, paresis, limb paralysis, cataracts, phacoclastic uveitis, frequent urination, marked decrease in body weight and in some pregnant females, also repeated abortions. The total morbidity rates in adult and young rabbits were 76.7% and 81.5%, respectively. The highest mortality rate was recorded in offspring (12.3%), followed by dams (5.6%), and the lowest recorded mortality rate was in males (0.04%). Post-mortem findings included enteritis, pale enlarged kidneys, congested leptomeninges, focal brain necrosis, and endometrial congestion. Histopathological examination revealed nonsuppurative meningoencephalitis and glial nodules with central necrosis in the brain, vacuolation and necrosis of renal tubular epithelium, and corneal ulceration and ruptured lens capsule with fragmentation of lenticular fibres. E. cuniculi were observed in the brain, retinal ganglion cells, kidneys, and liver. Transmission electron microscopy examination revealed the presence of different developmental stages of E. cuniculi in the brain and kidney. Presence of E. cuniculi was confirmed by conventional polymerase chain reaction using a universal 16S gene for Encephalitozoon spp. followed by sequencing and sequence analysis.

CONCLUSIONS: The presence of E. cuniculi in rabbits was confirmed at three farms in Egypt. Nervous signs and ocular lesions were the most predominant findings in these farms.

Elshazly, M. O., S. S. A. El-Rahman, D. A. Hamza, and M. E. Ali, "Pathological and bacteriological studies on reproductive tract abnormalities of she-camels (), emphasizing on zoonotic importance.", Journal of advanced veterinary and animal research, vol. 7, issue 4, pp. 633-646, 2020. Abstract

Objective: Infertility caused by reproductive pathologies plays a significant role in animal breeding and could result in massive economic losses to livestock owners. Hence, this study was designed to allocate various pathological lesions in the female reproductive tract of she-camels () slaughtered in Egypt and isolate the causative agents associated with those pathologies.

Materials and Methods: A total of 500 genitalia of adult nonpregnant she-camels aged between 6 and 15 years old were collected from three slaughterhouses at the Giza Governorate, Egypt, from August 2017 to August 2019. The uterus, cervix, and vagina were examined pathologically and microbiologically.

Results: The uteri of 152 cases (30.4%), cervices of 24 cases (4.8%), and vaginae of 20 cases (4.2%) showed pathological abnormalities. The uterine inflammatory lesions were detected in 119 cases (23.8%), and the non-inflammatory lesions were detected in 58 cases (11.6%). Pathological changes of the cervix comprised 4.8%, whereas vaginal abnormalities represented 4%. The total microbial recovery rate was 28.4%, and the isolated organisms included , , , , and , in addition to . Trials to isolate and species were negative; however, virological examination revealed the isolation of bovine herpesvirus type-1 in two cases.

Conclusion: Inflammatory lesions were the most prevailing pathological lesions observed along the genital tract of she-camels, and was the most prevalent isolate. The microbiological burden from the genital discharge could be of zoonotic importance to the examiner and could be a contaminant to the environment and, consequently, human. In addition, attention should be paid toward the possibility of infected she-camels to transmit such infections to farm animals in contact.

Hamza, D. A., R. M. Abd-Elsalam, S. M. Nader, M. Elhariri, R. Elhelw, and H. S. El-Mahallawy, "Pathways of Methicillin-Resistant in Animal Model: New Insights Regarding Public Health.", Infection and drug resistance, vol. 13, pp. 1593-1600, 2020. Abstract

Background: is considered one of the major threats regarding food safety worldwide. Methicillin-resistant (MRSA) strains in livestock, companion animals, and wild animals continue to be a potential risk to people working with them.

Aim: The current research aims to investigate the potential pathways of livestock-associated methicillin-resistant (LA-MRSA) strains in the body after oral infection using the experimental mouse model.

Methods: Seven groups of SPF male mice were purchased and housed. On day 1, six groups of mice were infected orally by the sterile gastric probe using 100 μL/mice of LA-MRSA bacterial suspension (1 × 10 colony-forming units (CFU)/mL). The remaining group was kept as negative controls. Over 15 days, these animals have been monitored. Fresh fecal samples were screened for LA-MRSA at day 0, day 7 and day 14 following oral administration of MRSA strains. All animals were sacrificed at day 15, and internal organs (liver, lung, kidney, and intestine) were harvested aseptically and divided into two sections. The first part was histopathologically investigated, while the other half has been tested for LA-MRSA re-isolation.

Result: The oral challenge of mice by MRSA strains showed that MRSA was re-isolated from feces and intestines of all inoculated mice groups and from internal organs (liver, lung, kidney and intestine) of most mice. Results were confirmed by the detection of the bacteria in gram-stained tissue sections and changes in H&E-stained histopathological tissue sections from these organs.

Conclusion: Data from the present study indicate the possible colonization of livestock-associated methicillin-resistant (LA-MRSA) in internal organs following oral infection and thus posing a risk for food-borne infection of MRSA. Infected animals could pass LA-MRSA through feces again, resulting in increased dispersion and environmental contamination.

Elhariri, M., R. Elhelw, S. Selim, M. Ibrahim, D. Hamza, and E. Hamza, "Virulence and Antibiotic Resistance Patterns of Extended-Spectrum Beta-Lactamase-Producing serovar Heidelberg Isolated from Broiler Chickens and Poultry Workers: A Potential Hazard.", Foodborne pathogens and disease, vol. 17, issue 6, pp. 373-381, 2020. Abstract

The current study investigated the emergence of multidrug-resistance (MDR), extended-spectrum beta-lactamase (ESBL)-producing serovar Heidelberg in broiler chickens and workers in poultry farms. A total of 33 . Heidelberg isolates were recovered; 24 from the broiler cloacal swabs and 9 from the farm workers. All the . Heidelberg isolates were tested for susceptibility to 11 antimicrobial agents and for the presence of resistance and virulence genes. MDR strains were found in 95.8% (23/24) and 88.8% (8/9) of the broiler and human isolates, respectively. Among the MDR strains, 66.6% of the broiler isolates and 55.5% of the human isolates were ESBL producing. The majority of broiler isolates showed resistance to ampicillin (100%) and ceftriaxone (91.6%), followed by ceftazidime and imipenem, (87.5%) and (75%). The resistance rate of the human isolates to those antibiotics were lower than the broiler isolates; ampicillin (88.8%), ceftriaxone (66.6%), ceftazidime (77.7%), and imipenem (66.6%). The resistance determinant genes found among the isolated strains was , , , , , , and . The most detected ESBL genes for broiler and human isolates were (63.7%) and (56.6%), followed by (48.5%), (39.4%), and (27.3%); whereas and were not detected. The finding of chromosomal and plasmid virulence genes revealed that the A (100%), , C, and (72.8%), C (66.7%), (63.6%), B (54.6%), and A and A (3.0%), while A and R were absent. An elevated rate of MDR Heidelberg in chickens is of potential great health risk. This signifies the role of the food of animal origin as a reservoir of MDR that can affect the human health.

2019
Elshafiee, E. A., S. M. Nader, S. M. Dorgham, and D. A. Hamza, "Carbapenem-resistant Originating from Farm Animals and People in Egypt.", Journal of veterinary research, vol. 63, issue 3, pp. 333-337, 2019. Abstract

Introduction: Carbapenem-resistant (CRPA) has become the leading cause of health care-associated infections. Treatment is difficult due to the lack of an effective antimicrobial therapy, and mortality is high. This study investigated the occurrence of CRPA in farm animals (buffaloes and cattle), livestock drinking water, and humans in Egypt.

Material and Methods: A total of 180 samples were examined: 50 faecal each from buffaloes and cattle, 30 of livestock drinking water, and 50 stool from humans. The samples were cultured on cetrimide agar and the plates were incubated aerobically at 37°C for 24 h. The isolates were examined for the presence of the , , and carbapenemase-encoding genes using PCR and investigated for the exotoxin A () gene. The gene from carbapenem- group resistant isolates was phylogenetically analysed.

Results: was isolated from buffaloes, cattle, drinking water, and humans, with occurrences of 40%, 34%, 10%, and 20%, respectively. Carbapenem resistance genes were found in 60%, 59%, 67%, and 70% in buffalo, cattle, water and human samples, respectively. The gene was detected in 80% of samples. The phylogenetic analysis showed that cattle and water sequences were in one cluster and more related to each other than to human isolates.

Conclusion: Occurrence of CRPA among farm animals, drinking water, and humans was high, reflecting the environmental origin of and highlighting contaminated water as a potential transmitter of CRPA to livestock and next to humans.

Ahmed, Z. S., E. A. Elshafiee, H. S. Khalefa, M. Kadry, and D. A. Hamza, "Evidence of colistin resistance genes ( and ) in wild birds and its public health implication in Egypt.", Antimicrobial resistance and infection control, vol. 8, pp. 197, 2019. Abstract

Background: Antimicrobial resistance has become one of the most severe global threats to human and veterinary Medicinstin is an effective therapeutic agent against multi-drug-resistant pathogens. However, the discovery of transferable plasmids that confer resistance to colistin ( 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 and from the different samples were performed using conventional culture techniques and biochemical identification. PCR amplification of the genes was performed in all positive isolates. Sequencing of -1 genes from three randomly selected carrying mcr-1 isolates; wild birds, water and humans was performed.

Result: The bacteriological examination of the samples showing isolates of , , and . The results of multiplex PCR of the genes revealed that was the most prevalent gram-negative bacterium harbouring the genes, whereas a low prevalence was observed for . The prevalence of 1 in resident birds, migratory birds, water sources and humans were 10.4, 20,16.6 and 9.6% while the prevalence of -2 were 1.4, 3.6, 11.1 and 9.6%, respectively. Sequencing of the gene from the three carrying - isolates indicated a possible correlation between the wild bird and surface water isolates.

Conclusion: The detection of -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.

El Shazly, M. O., S. A. S. El-Rahman, D. A. Hamza, and M. E. Ali, "OVARIAN NEOPLASMS IN DROMEDARY CAMEL: PREVALENCE, TYPES AND PATHOLOGY", Journal of Camel Practice and Research, vol. 26 , issue 3, pp. 1-9, 2019.
Al-Amery, K., M. Elhariri, A. Elsayed, G. El-Moghazy, R. Elhelw, H. El-Mahallawy, M. El Hariri, and D. Hamza, "Vancomycin-resistant isolated from camel meat and slaughterhouse workers in Egypt.", Antimicrobial resistance and infection control, vol. 8, pp. 129, 2019. Abstract

Background: The emergence of vancomycin-resistant (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.

Methods: 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 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 gene in phenotypically oxacillin (OXA)- and cefoxitin (FOX)-resistant isolates. The resistance of to vancomycin (VAN) was tested by broth microdilution and confirmed by PCR targeting the and genes. The and genes were sequenced.

Result: 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 and genes. Additionally, all VRSA isolates were also classified as methicillin-resistant (MRSA). The amplicons of the isolates from human and camel meat were homologous and clustered with a Chinese reference isolate sequence.

Conclusion: 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.

2018
Hamza, D., R. Elhelw, M. Elhariri, and E. Ragab, "Genotyping and antimicrobial resistance patterns of Helicobacter pylori in human and dogs associated with A2142G and A2143G point mutations in clarithromycin resistance.", Microbial pathogenesis, vol. 123, pp. 330-338, 2018. Abstract

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 cagAvacA combinations 76.6% (69/90) and 65.2% (30/46) in human and dogs, respectively. Allelic diversity in vacA gene was obviously observed, while cagAvacA 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.

Elhariri, M., D. Hamza, R. Elhelw, and E. Hamza, "Occurrence of cagA vacA s1a m1 i1 Helicobacter pylori in farm animals in Egypt and ability to survive in experimentally contaminated UHT milk.", Scientific reports, vol. 8, issue 1, pp. 14260, 2018. Abstract

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 cagAvacAs1a 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.

Abdel-moein, K. A., and D. A. Hamza, "Rat as an overlooked reservoir for Coxiella burnetii: A public health implication.", Comparative immunology, microbiology and infectious diseases, vol. 61, pp. 30-33, 2018. Abstract

Q fever is a zoonosis with a mounting public health concern throughout the world. Rodents have been assumed to be a potential reservoir for Coxiella burnetii, a bacterium which causes Q fever. The current study was carried out to investigate the possible role of rats in the epidemiology of such disease. For this purpose, fecal samples were collected from 75 rats (55 Rattus norvegicus and 20 Rattus rattus) trapped from Giza governorate, Egypt. DNAs were extracted and samples were examined for the presence of C. burnetii using nested PCR technique. Out of examined rats, 5 yielded C. burnetii in their feces with an overall prevalence 6.7%, whereas the prevalence rates among R. norvegicus and R. rattus were (2/55) 3.6% and (3/20) 15% respectively. In addition, the phylogenetic analysis of three selected amplicons (2 R. rattus and one R. norvegicus) revealed that these sequences were highly related to each others and to those detected among humans. In conclusion, the results of the current study point out the role of rats as a potential reservoir for C. burnetii.

2017
Elhariri, M., D. Hamza, R. Elhelw, and S. M. Dorgham, "Extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa in camel in Egypt: potential human hazard.", Annals of clinical microbiology and antimicrobials, vol. 16, issue 1, pp. 21, 2017 Mar 31. Abstract2.pdf

BACKGROUND: 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.

METHODS: 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, bla, bla, and bla.

RESULTS: 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 (bla28.5%, bla38%, bla33.3% and bla23.8%).

CONCLUSIONS: 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.

Abdel-moein, K. A., and D. A. Hamza, "The burden of Coxiella burnetii among aborted dairy animals in Egypt and its public health implications.", Acta tropica, vol. 166, pp. 92-95, 2017 Feb. Abstract

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.

Hamza, D., S. Dorgham, and A. Hakim, "Toxinotyping and antimicrobial resistance of Clostridium perfringens isolated from processed chicken meat products", J Vet Res , vol. 61, pp. 53-58, 2017, 2017.
2016
Abdel-moein, K. A., and D. A. Hamza, "Norway rat (Rattus norvegicus) as a potential reservoir for Echinococcus granulosus: A public health implication.", Acta parasitologica, vol. 61, issue 4, pp. 815-819, 2016 Dec 01. Abstract

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.

Hamza, E., S. M. Dorgham, and D. A. Hamza, "Carbapenemase-producing Klebsiella pneumoniae in broiler poultry farming in Egypt.", Journal of global antimicrobial resistance, vol. 7, pp. 8-10, 2016 Dec. Abstract

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.

Elhariri, M., D. Hamza, R. Elhelw, and M. Refai, "Eucalyptus Tree: A Potential Source of Cryptococcus neoformans in Egyptian Environment.", International journal of microbiology, vol. 2016, pp. 4080725, 2016. Abstract

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.

Abdel-moein, K. A., and D. A. Hamza, "Occurrence of human pathogenic Clostridium botulinum among healthy dairy animals: an emerging public health hazard.", Pathogens and global health, vol. 110, issue 1, pp. 25-9, 2016. Abstract

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.

2014
and A., G. H. N. H. D., and H. D. A., "Epidemiological studies on Clostridium perfringens food poisoning in retail foods,", International Symposium on Food Safety and Quality: Applications of Nuclear and Related Techniques - IAEA CN-222., Vienna, pp. 79, 2014.
2013
Ghoneim, N. H., W. W. M. Reda, S. F. Darwish, and D. A. Hamza, "Characterization of Clostridium perfringens Enterotoxin in Food Animals and Human", Global Veterinaria, vol. 10, issue 2, pp. 171-175, 2013. characterization_of__clostridium_perfringens.pdf