Last data update: Sep 16, 2024. (Total: 47680 publications since 2009)
Records 1-19 (of 19 Records) |
Query Trace: Amer S [original query] |
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Development of an international glossary for clinical guidelines collaboration
Christensen RE , Yi MD , Kang BY , Ibrahim SA , Anvery N , Dirr M , Adams S , Amer YS , Bisdorff A , Bradfield L , Brown S , Earley A , Fatheree LA , Fayoux P , Getchius T , Ginex P , Graham A , Green CR , Gresele P , Hanson H , Haynes N , Hegedüs L , Hussein H , Jakhmola P , Kantorova L , Krishnasamy R , Krist A , Landry G , Lease ED , Ley L , Marsden G , Meek T , Meremikwu M , Moga C , Mokrane S , Mujoomdar A , Newton S , O'Flynn N , Perkins GD , Smith EJ , Prematunge C , Rychert J , Saraco M , Schünemann HJ , Senerth E , Sinclair A , Shwayder J , Stec C , Tanni S , Taske N , Temple-Smolkin RL , Thomas L , Thomas S , Tonnessen B , Turner AS , Van Dam A , van Doormaal M , Wan YL , Ventura CB , McFarlane E , Morgan RL , Ogunremi T , Alam M . J Clin Epidemiol 2023 158 84-91 OBJECTIVE: Clinical practice guidelines are often created through collaboration among organizations. Use of inconsistent terminology may cause poor communication and delays. This study aimed to develop a glossary of terms related to collaboration in guideline development. STUDY DESIGN AND SETTING: A literature review of collaborative guidelines was performed to develop an initial list of terms related to guideline collaboration. The list of terms was presented to the members of the Guideline International Network Guidelines Collaboration Working Group, who provided presumptive definitions for each term and proposed additional terms to be included. The revised list was subsequently reviewed by an international, multidisciplinary panel of expert stakeholders. Recommendations received during this pre-Delphi review were implemented to augment an initial draft glossary. The glossary was then critically evaluated and refined through two rounds of Delphi surveys and a virtual consensus meeting with all panel members as Delphi participants. RESULTS: Forty-nine experts participated in the pre-Delphi survey and 44 participated in the two-round Delphi process. Consensus was reached for 37 terms and definitions. CONCLUSION: Uptake and utilization of this guideline collaboration glossary by key organizations and stakeholder groups may facilitate collaboration among guideline-producing organizations by improving communication, minimizing conflicts, and increasing guideline development efficiency. |
A memorandum of understanding has facilitated guideline development involving collaborating groups
Alam M , Getchius TS , Schünemann H , Amer YS , Bak A , Fatheree LA , Ginex P , Jakhmola P , Marsden GL , McFarlane E , Meremikwu M , Taske N , Temple-Smolkin RL , Ventura C , Burgers J , Bradfield L , O'Brien MD , Einhaus K , Kopp IB , Munn Z , Scudeller L , Schaefer C , Ibrahim SA , Kang BY , Ogunremi T , Morgan RL . J Clin Epidemiol 2021 144 8-15 OBJECTIVE: Collaboration between groups can facilitate the development of high-quality guidelines. While collaboration is often desirable, misunderstandings can occur. One method to minimize misunderstandings is the pre-specification of terms of engagement in a memorandum of understanding (MOU). This study considered when an MOU may be most helpful, and which key elements should be included. STUDY DESIGN AND SETTING: An international panel of representatives from guideline groups was convened. A literature review to identify publications and other documents relevant to the establishment of MOUs between two or more guideline groups, supplemented by available source documents, was used to inform development of a draft MOU resource. This was iteratively refined until consensus was achieved. RESULTS: The level of detail in an MOU may vary based on institutional preferences and the particular collaboration. Elements within an MOU include those pertaining to: (1) scope and purpose; (2) leadership and team; (3) methods and commitment; (4) review and endorsement; and (5) publication and dissemination. CONCLUSION: Since groups may have different expectations regarding how a collaboration will unfold, an MOU may mitigate preventable misunderstandings. The result may be a higher likelihood of producing a guideline without disruption and delay. |
An international needs assessment survey of guideline developers demonstrates variability in resources and challenges to collaboration between organizations
Sultan S , Siedler MR , Morgan RL , Ogunremi T , Dahm P , Fatheree LA , Getchius TSD , Ginex PK , Jakhmola P , McFarlane E , Murad MH , Temple Smolkin RL , Amer YS , Alam M , Kang BY , Falck-Ytter Y , Mustafa RA . J Gen Intern Med 2021 37 (11) 2669-2677 BACKGROUND: The development of rigorous, high-quality clinical guidelines increases the need for resources and skilled personnel within guideline-producing organizations. While collaboration between organizations provides a unique opportunity to pool resources and save time and effort, the collaboration presents its own unique challenges. OBJECTIVE: To assess the perceived needs and current challenges of guideline producers worldwide related to guideline development and collaboration efforts. DESIGN: Survey questions were developed by the Guidelines International Network and the US GRADE Network, pilot-tested among attendees of a guideline development workshop, and disseminated electronically using convenience and snowball sampling methods. PARTICIPANTS: A total of 171 respondents representing 30 countries and more than 112 unique organizations were included in this analysis. MAIN MEASURES: The survey included free-response, multiple-choice, and seven-point Likert-scale questions. Questions assessed respondents' perceived value of guidelines, resource availability and needs, guideline development processes, and collaboration efforts of their organization. KEY RESULTS: Time required to develop high-quality systematic reviews and guidelines was the most relevant need (median=7; IQR=5.5-7). In-house resources to conduct literature searches (median=4; IQR=3-6) and the resources to develop rigorous guidelines rapidly (median=4; IQR=2-5) were perceived as the least available resources. Difficulties reconciling differences in guideline methodology (median=6; IQR=4-7) and the time required to establish collaborative agreements (median=6; IQR=5-6) were the most relevant barriers to collaboration between organizations. Results also indicated a general need for improvement in conflict of interest (COI) disclosure policies. CONCLUSION: The survey identified organizational challenges in supporting rigorous guideline development, including the time, resources, and personnel required. Connecting guideline developers to existing databases of high-quality systematic reviews and the use of freely available online platforms may facilitate guideline development. Guideline-producing organizations may also consider allocating resources to hiring or training personnel with expertise in systematic review methodologies or utilizing resources more effectively by establishing collaborations with other organizations. |
Scope and extent of healthcare-associated Middle East respiratory syndrome coronavirus transmission during two contemporaneous outbreaks in Riyadh, Saudi Arabia, 2017.
Alanazi KH , Killerby ME , Biggs HM , Abedi GR , Jokhdar H , Alsharef AA , Mohammed M , Abdalla O , Almari A , Bereagesh S , Tawfik S , Alresheedi H , Alhakeem RF , Hakawi A , Alfalah H , Amer H , Thornburg NJ , Tamin A , Trivedi S , Tong S , Lu X , Queen K , Li Y , Sakthivel SK , Tao Y , Zhang J , Paden CR , Al-Abdely HM , Assiri AM , Gerber SI , Watson JT . Infect Control Hosp Epidemiol 2019 40 (1) 79-88 OBJECTIVE: To investigate a Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak event involving multiple healthcare facilities in Riyadh, Saudi Arabia; to characterize transmission; and to explore infection control implications. DESIGN: Outbreak investigation. SETTING: Cases presented in 4 healthcare facilities in Riyadh, Saudi Arabia: a tertiary-care hospital, a specialty pulmonary hospital, an outpatient clinic, and an outpatient dialysis unit. METHODS: Contact tracing and testing were performed following reports of cases at 2 hospitals. Laboratory results were confirmed by real-time reverse transcription polymerase chain reaction (rRT-PCR) and/or genome sequencing. We assessed exposures and determined seropositivity among available healthcare personnel (HCP) cases and HCP contacts of cases. RESULTS: In total, 48 cases were identified, involving patients, HCP, and family members across 2 hospitals, an outpatient clinic, and a dialysis clinic. At each hospital, transmission was linked to a unique index case. Moreover, 4 cases were associated with superspreading events (any interaction where a case patient transmitted to >/=5 subsequent case patients). All 4 of these patients were severely ill, were initially not recognized as MERS-CoV cases, and subsequently died. Genomic sequences clustered separately, suggesting 2 distinct outbreaks. Overall, 4 (24%) of 17 HCP cases and 3 (3%) of 114 HCP contacts of cases were seropositive. CONCLUSIONS: We describe 2 distinct healthcare-associated outbreaks, each initiated by a unique index case and characterized by multiple superspreading events. Delays in recognition and in subsequent implementation of control measures contributed to secondary transmission. Prompt contact tracing, repeated testing, HCP furloughing, and implementation of recommended transmission-based precautions for suspected cases ultimately halted transmission. |
Zoonotic Cryptosporidium species and subtypes in lambs and goat kids in Algeria
Baroudi D , Hakem A , Adamu H , Amer S , Khelef D , Adjou K , Dahmani H , Chen X , Roellig D , Feng Y , Xiao L . Parasit Vectors 2018 11 (1) 582 BACKGROUND: Little is known on the occurrence and identity of Cryptosporidium species in sheep and goats in Algeria. This study aimed at investigating the occurrence of Cryptosporidium species in lambs and goat kids younger than 4 weeks. METHODS: A total of 154 fecal samples (62 from lambs and 92 from kid goats) were collected from 13 sheep flocks in Medea, Algeria and 18 goat flocks across Algiers and Boumerdes. They were screened for Cryptosporidium spp. by nested-PCR analysis of a fragment of the small subunit (SSU) rRNA gene, followed by restriction fragment length polymorphism and sequence analyses to determine the Cryptosporidium species present. Cryptosporidium parvum and C. ubiquitum were further subtyped by sequence analysis of the 60 kDa glycoprotein gene. RESULTS: Cryptosporidium spp. were detected in 17 fecal samples (11.0%): 9 from lambs (14.5%) and 8 from goat kids (8.7%). The species identified included C. parvum in 3 lambs, C. xiaoi in 6 lambs and 6 goat kids, and C. ubiquitum in 2 goat kids. Cryptosporidium infections were detected mostly in animals during the first two weeks of life (7/8 for goat kids and 7/9 for lambs) and in association with diarrhea occurrence (7/17 or 41.2% goat kids and 7/10 or 70.0% lambs with diarrhea were positive for Cryptosporidium spp.). Subtyping of C. parvum and C. ubiquitum isolates identified the zoonotic IIaA13G2R1 and XIIa subtype families, respectively. Minor differences in the SSU rRNA gene sequences were observed between C. xiaoi from sheep and goats. CONCLUSIONS: Results of this study indicate that three Cryptosporidium species occur in lambs and goat kids in Algeria, including zoonotic C. parvum and C. ubiquitum. They are associated with the occurrence of neonatal diarrhea. |
Divergent Cryptosporidium parvum subtype and Enterocytozoon bieneusi genotypes in dromedary camels in Algeria.
Baroudi D , Zhang H , Amer S , Khelef D , Roellig DM , Wang Y , Feng Y , Xiao L . Parasitol Res 2018 117 (3) 905-910 Little information is available on the occurrence of the zoonotic protists Cryptosporidium spp. and none on Enterocytozoon bieneusi in camels. This preliminary study was conducted to examine the identity of Cryptosporidium subtypes and E. bieneusi genotypes in dromedary camels in Algeria. A total of 39 fecal specimens were collected from young camels. PCR-sequence analysis of the small subunit rRNA was used to detect and genotype Cryptosporidium spp. Cryptosporidium parvum present was further subtyped by sequence analysis of the 60 kDa glycoprotein gene. PCR-sequence analysis of the ribosomal internal transcribed spacer gene was used to detect and genotype E. bieneusi. Altogether, two and eight of the specimens analyzed were positive for C. parvum and E. bieneusi, respectively. The former was identified as a new subtype that is genetically related to the C. hominis If subtype family, whereas the latter was identified as two related genotypes (Macaque1 and a novel genotype) in the newly assigned E. bieneusi genotype group 8. Although they are not known hosts for C. parvum and E. bieneusi, camels are apparently infected with genetically distinct variants of these pathogens. |
Viral etiology, seasonality and severity of hospitalized patients with severe acute respiratory infections in the Eastern Mediterranean Region, 2007-2014
Horton KC , Dueger EL , Kandeel A , Abdallat M , El-Kholy A , Al-Awaidy S , Kohlani AH , Amer H , El-Khal AL , Said M , House B , Pimentel G , Talaat M . PLoS One 2017 12 (7) e0180954 INTRODUCTION: Little is known about the role of viral respiratory pathogens in the etiology, seasonality or severity of severe acute respiratory infections (SARI) in the Eastern Mediterranean Region. METHODS: Sentinel surveillance for SARI was conducted from December 2007 through February 2014 at 20 hospitals in Egypt, Jordan, Oman, Qatar and Yemen. Nasopharyngeal and oropharyngeal swabs were collected from hospitalized patients meeting SARI case definitions and were analyzed for infection with influenza, respiratory syncytial virus (RSV), adenovirus (AdV), human metapneumovirus (hMPV) and human parainfluenza virus types 1-3 (hPIV1-3). We analyzed surveillance data to calculate positivity rates for viral respiratory pathogens, describe the seasonality of those pathogens and determine which pathogens were responsible for more severe outcomes requiring ventilation and/or intensive care and/or resulting in death. RESULTS: At least one viral respiratory pathogen was detected in 8,753/28,508 (30.7%) samples tested for at least one pathogen and 3,497/9,315 (37.5%) of samples tested for all pathogens-influenza in 3,345/28,438 (11.8%), RSV in 3,942/24,503 (16.1%), AdV in 923/9,402 (9.8%), hMPV in 617/9,384 (6.6%), hPIV1 in 159/9,402 (1.7%), hPIV2 in 85/9,402 (0.9%) and hPIV3 in 365/9,402 (3.9%). Multiple pathogens were identified in 501/9,316 (5.4%) participants tested for all pathogens. Monthly variation, indicating seasonal differences in levels of infection, was observed for all pathogens. Participants with hMPV infections and participants less than five years of age were significantly less likely than participants not infected with hMPV and those older than five years of age, respectively, to experience a severe outcome, while participants with a pre-existing chronic disease were at increased risk of a severe outcome, compared to those with no reported pre-existing chronic disease. CONCLUSIONS: Viral respiratory pathogens are common among SARI patients in the Eastern Mediterranean Region. Ongoing surveillance is important to monitor changes in the etiology, seasonality and severity of pathogens of interest. |
The 17th International Congress on Infectious Diseases Workshop on Developing Infection Prevention and Control Resources for Low to Middle Income Countries
Sastry S , Masroor N , Bearman G , Hajjeh R , Holmes A , Memish Z , Lassmann B , Pittet D , Macnab F , Kamau R , Wesangula E , Pokharel P , Brown P , Daily F , Amer F , Torres J , O'Ryan M , Gunturu R , Bulabula A , Mehtar S . Int J Infect Dis 2017 57 138-143 Hospital acquired infections (HAIs) are a major concern to healthcare systems around the world. They are associated with significant morbidity and mortality, in addition to increased hospitalization costs. Recent outbreaks including MERS (Middle East Respiratory Syndrome) coronavirus and Ebola have highlighted the importance of infection control. Further, HAIs especially with multi-drug resistant gram negative rods (MDRO-GNRs) have become a top global priority. Though adequate approaches and guidelines have been in existence for many years and have sometimes proven effective in some countries, the implementation of such approaches in low and middle income countries (LMICs) is often restricted due to limited resources and underdeveloped infrastructure. While evidence based infection control principles and practices are universal, studies are needed to evaluate simplified approaches that can be better adapted to LMIC needs, in order to practically guide IPC practices. A group of experts from around the world attended a workshop held at the 17th International Congress on Infectious Diseases conference in Hyderabad, India, to discuss the existing IPC practices in LMICs, and how these can be best improved within the local context. |
Comparative genomic analysis of the IId subtype family of Cryptosporidium parvum.
Feng Y , Li N , Roellig DM , Kelley A , Liu G , Amer S , Tang K , Zhang L , Xiao L . Int J Parasitol 2017 47 (5) 281-290 Host adaptation is known to occur in Cryptosporidium parvum, with IIa and IId subtype families preferentially infecting calves and lambs, respectively. To improve our understanding of the genetic basis of host adaptation in Cryptosporidium parvum, we sequenced the genomes of two IId specimens and one IIa specimen from China and Egypt using the Illumina technique and compared them with the published IIa IOWA genome. Sequence data were obtained for >99.3% of the expected genome. Comparative genomic analysis identified differences in numbers of three subtelomeric gene families between sequenced genomes and the reference genome, including those encoding SKSR secretory proteins, the MEDLE family of secretory proteins, and insulinase-like proteases. These gene gains and losses compared with the reference genome were confirmed by PCR analysis. Altogether, 5,191-5,766 single nucleotide variants were seen between genomes sequenced in this study and the reference genome, with most SNVs occurring in subtelomeric regions of chromosomes 1, 4, and 6. The most highly polymorphic genes between IIa and IId encode mainly invasion-associated and immunodominant mucin proteins, and other families of secretory proteins. Further studies are needed to verify the biological significance of these genomic differences. |
Identity of Fasciola spp. in sheep in Egypt
Amer S , ElKhatam A , Zidan S , Feng Y , Xiao L . Parasit Vectors 2016 9 (1) 623 BACKGROUND: In Egypt, liver flukes, Fasciola spp. (Digenea: Fasciolidae), have a serious impact on the farming industry and public health. Both Fasciola hepatica and Fasciola gigantica are known to occur in cattle, providing the opportunity for genetic recombination. Little is known on the identity and genetic variability of Fasciola populations in sheep. METHODS: This study was performed to determine the prevalence of liver flukes in sheep in Menofia Province as a representative area of the delta region in Egypt, as measured by postmortem examination of slaughtered animals at three abattoirs. The identity and genetic variability of Fasciola spp. in slaughtered animals were determined by PCR-sequence analysis of the nuclear ribosomal internal transcribed spacer 1 (ITS1) and the mitochondrial NADH dehydrogenase subunit 1 (nad1) genes. RESULTS: Physical inspection of the liver indicated that 302 of 2058 (14.7%) slaughtered sheep were infected with Fasciola spp. Sequence analysis of the ITS1 and nad1 genes of liver flukes from 17 animals revealed that 11 animals were infected with F. hepatica, four with F. gigantica, and two with both species. Seventy eight of 103 flukes genetically characterized from these animals were F. hepatica, 23 were F. gigantica, and two had ITS1 sequences identical to F. hepatica but nad1 sequences identical to F. gigantica. nad1 sequences of Egyptian isolates of F. gigantica showed pronounced differences from those in the GenBank database. Egyptian F. gigantica haplotypes formed haplogroup D, which clustered in a sister clade with haplogroups A, B and C circulating in Asia, indicating the existence of geographic isolation in the species. CONCLUSIONS: Both F. hepatica and F. gigantica are prevalent in sheep in Egypt and an introgressed form of the two occurs as the result of genetic recombination. In addition, a geographically isolated F. gigantica population is present in the country. The importance of these observations in epidemiology of fascioliasis needs to be examined in future studies. |
Transmission of Middle East Respiratory Syndrome Coronavirus Infections in Healthcare Settings, Abu Dhabi.
Hunter JC , Nguyen D , Aden B , Al Bandar Z , Al Dhaheri W , Abu Elkheir K , Khudair A , Al Mulla M , El Saleh F , Imambaccus H , Al Kaabi N , Sheikh FA , Sasse J , Turner A , Abdel Wareth L , Weber S , Al Ameri A , Abu Amer W , Alami NN , Bunga S , Haynes LM , Hall AJ , Kallen AJ , Kuhar D , Pham H , Pringle K , Tong S , Whitaker BL , Gerber SI , Al Hosani FI . Emerg Infect Dis 2016 22 (4) 647-56 Middle East respiratory syndrome coronavirus (MERS-CoV) infections sharply increased in the Arabian Peninsula during spring 2014. In Abu Dhabi, United Arab Emirates, these infections occurred primarily among healthcare workers and patients. To identify and describe epidemiologic and clinical characteristics of persons with healthcare-associated infection, we reviewed laboratory-confirmed MERS-CoV cases reported to the Health Authority of Abu Dhabi during January 1, 2013-May 9, 2014. Of 65 case-patients identified with MERS-CoV infection, 27 (42%) had healthcare-associated cases. Epidemiologic and genetic sequencing findings suggest that 3 healthcare clusters of MERS-CoV infection occurred, including 1 that resulted in 20 infected persons in 1 hospital. MERS-CoV in healthcare settings spread predominantly before MERS-CoV infection was diagnosed, underscoring the importance of increasing awareness and infection control measures at first points of entry to healthcare facilities. |
Morphologic and Genotypic Characterization of Psoroptes Mites from Water Buffaloes in Egypt.
Amer S , Abd El Wahab T , El Naby Metwaly A , Feng Y , Xiao L . PLoS One 2015 10 (10) e0141554 Species delimitation of Psoroptes spp. and identity of the parasite in water buffaloes remain poorly defined. In this study, Psoroptes infestation on three water buffalo farms in Egypt was examined based on morphometric characteristics, especially the opisthosomal setae of adult male mites. Clinical investigations showed that 28% (196/700) of the sampled animals had mange infestation. Microscopic examinations of 80 skin scrapings indicated the occurrence of Psoroptes mites in 17 (21.3%) samples, Sarcoptes mites in 27 (33.7%) samples, and the concurrence of both in 36 (45.0%) samples. Morphologically, the Psoroptes parasite was identified as Psoroptes natalensis. DNA sequence analysis of the second internal transcribed spacer (ITS2) in 11 representative samples confirmed the diagnosis and suggested the presence of a distinct variety of Psoroptes natalensis in Egypt. |
Molecular characterization of Echinococcus granulosus sensu lato from farm animals in Egypt.
Amer S , Helal IB , Kamau E , Feng Y , Xiao L . PLoS One 2015 10 (3) e0118509 Little is known on the diversity and public health significance of Echinococcus species in livestock in Egypt. In this study, 37 individual hydatid cysts were collected from dromedary camels (n=28), sheep (n=7) and buffalos (n=2). DNA was extracted from protoscoleces/germinal layer of individual cysts and amplified by PCR targeting nuclear (actin II) and mitochondrial (COX1 and NAD1) genes. Direct sequencing of amplicons indicated the presence of Echinococcus canadenesis (G6 genotype) in 26 of 28 camel cysts, 3 of 7 sheep cysts and the 2 buffalo derived cysts. In contrast, Echinococcus granulosus sensu stricto (G1 genotype) was detected in one cyst from a camel and 4 of 7 cysts from sheep, whereas Echinococcus ortleppi (G5 genotype) was detected in one cyst from a camel. This is the first identification of E. ortleppi in Egypt. |
Preliminary molecular characterizations of Sarcoptes scaibiei (Acari: Sarcoptidae) from farm animals in Egypt.
Amer S , Wahab TA , Metwaly Ael N , Ye J , Roellig D , Feng Y , Xiao L . PLoS One 2014 9 (4) e94705 Little is known about the genetic diversity of Sarcoptes scabiei mites in farm animals in Egypt. In this study, we characterized S. scabiei in 25 skin scrapes from water buffalo, cattle, sheep, and rabbits at the nuclear marker ITS2 and mitochondrial markers COX1 and 16S rRNA. Sequences of the ITS2 showed no host segregation or geographical isolation, whereas those of the mitochondrial COX1 and 16S rRNA genes indicated the presence of both host-adapted and geographically segregated populations of S. scabiei. Host adaptation may limit inter-species transmission of. S. scabiei, thus restrict gene flow among S. scabiei from different hosts. This is the first report on the molecular characterization of sarcoptic mites in Egypt. Further genetic studies involving larger numbers of specimens, especially those from humans and companion animals, are needed to understand the molecular epidemiology of sarcoptic mange in Egypt. |
Distribution and clinical manifestations of Cryptosporidium species and subtypes in HIV/AIDS patients in Ethiopia
Adamu H , Petros B , Zhang G , Kassa H , Amer S , Ye J , Feng Y , Xiao L . PLoS Negl Trop Dis 2014 8 (4) e2831 BACKGROUND: Cryptosporidiosis is an important cause for chronic diarrhea and death in HIV/AIDS patients. Among common Cryptosporidium species in humans, C. parvum is responsible for most zoonotic infections in industrialized nations. Nevertheless, the clinical significance of C. parvum and role of zoonotic transmission in cryptosporidiosis epidemiology in developing countries remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this cross-sectional study, 520 HIV/AIDS patients were examined for Cryptosporidium presence in stool samples using genotyping and subtyping techniques. Altogether, 140 (26.9%) patients were positive for Cryptosporidium spp. by PCR-RFLP analysis of the small subunit rRNA gene, belonging to C. parvum (92 patients), C. hominis (25 patients), C. viatorum (10 patients), C. felis (5 patients), C. meleagridis (3 patients), C. canis (2 patients), C. xiaoi (2 patients), and mixture of C. parvum and C. hominis (1 patient). Sequence analyses of the 60 kDa glycoprotein gene revealed a high genetic diversity within the 82 C. parvum and 19 C. hominis specimens subtyped, including C. parvum zoonotic subtype families IIa (71) and IId (5) and anthroponotic subtype families IIc (2), IIb (1), IIe (1) and If-like (2), and C. hominis subtype families Id (13), Ie (5), and Ib (1). Overall, Cryptosporidium infection was associated with the occurrence of diarrhea and vomiting. Diarrhea was attributable mostly to C. parvum subtype family IIa and C. hominis, whereas vomiting was largely attributable to C. hominis and rare Cryptosporidium species. Calf contact was identified as a significant risk factor for infection with Cryptosporidium spp., especially C. parvum subtype family IIa. CONCLUSIONS/SIGNIFICANCE: Results of the study indicate that C. parvum is a major cause of cryptosporidiosis in HIV-positive patients and zoonotic transmission is important in cryptosporidiosis epidemiology in Ethiopia. In addition, they confirm that different Cryptosporidium species and subtypes are linked to different clinical manifestations. |
Cryptosporidium parvum IId family: clonal population and dispersal from Western Asia to other geographical regions.
Wang R , Zhang L , Axen C , Bjorkman C , Jian F , Amer S , Liu A , Feng Y , Li G , Lv C , Zhao Z , Qi M , Dong H , Wang H , Sun Y , Ning C , Xiao L . Sci Rep 2014 4 4208 In this study, 111 Cryptosporidium parvum IId isolates from several species of animals in China, Sweden, and Egypt were subtyped by multilocus sequence typing (MLST). One to eleven subtypes were detected at each of the 12 microsatellite, minisatellite, and single nucleotide polymorphism (SNP) loci, forming 25 MLST subtypes. Host-adaptation and significant geographical segregation were both observed in the MLST subtypes. A clonal population structure was seen in C. parvum IId isolates from China and Sweden. Three ancestral lineages and the same RPGR sequence were shared by these isolates examined. Therefore, the present genetic observations including the higher nucleotide diversity of C. parvum IId GP60 sequences in Western Asia, as well as the unique distribution of IId subtypes (almost exclusively found in Asia, Europe, and Egypt) and in combination with the domestication history of cattle, sheep, and goats, indicated that C. parvum IId subtypes were probably dispersed from Western Asia to other geographical regions. More population genetic structure studies involving various C. parvum subtype families using high-resolution tools are needed to better elucidate the origin and dissemination of C. parvum in the world. |
Prevalence and characterization of Cryptosporidium spp. in dairy cattle in Nile River delta provinces, Egypt
Amer S , Zidan S , Adamu H , Ye J , Roellig D , Xiao L , Feng Y . Exp Parasitol 2013 135 (3) 518-23 Molecular characterizations of Cryptosporidium spp. in dairy cattle in industrialized nations have mostly shown a dominance of Cryptosporidium parvum, especially its IIa subtypes in pre-weaned calves. Few studies, however, have been conducted on the distribution of Cryptosporidium species and C. parvum subtypes in various age groups of dairy cattle in developing countries. In this study, we examined the prevalence and molecular characteristics of Cryptosporidium in dairy cattle in four Nile River delta provinces in Egypt. Modified Ziehl-Neelsen acid-fast microscopy was used to screen for Cryptosporidium oocysts in 1974 fecal specimens from animals of different ages on 12 farms. Positive fecal specimens were identified from all studied farms with an overall prevalence of 13.6%. By age group, the infection rates were 12.5% in pre-weaned calves, 10.4% in post-weaned calves, 22.1% in heifers, and 10.7% in adults. PCR-RFLP and DNA sequence analyses of microscopy-positive fecal specimens revealed the presence of four major Cryptosporidium species. In pre-weaned calves, C. parvum was most common (30/69 or 43.5%), but Cryptosporidium ryanae (13/69 or 18.8%), Cryptosporidium bovis (7/69 or 10.2%), and Cryptosporidium andersoni (7/69 or 10.2%) were also present at much higher frequencies seen in most industrialized nations. Mixed infections were seen in 12/69 (17.4%) of genotyped specimens. In contrast, C. andersoni was the dominant species (193/195 or 99.0%) in post-weaned calves and older animals. Subtyping of C. parvum based on sequence analysis of the 60kDa glycoprotein gene showed the presence of subtypes IIdA20G1 in nine specimens, IIaA15G1R1 in 27 specimens, and a rare subtype IIaA14G1R1r1b in one specimen. The common occurrence of non-C. parvum species and IId subtypes in pre-weaned calves is a distinct feature of cryptosporidiosis transmission in dairy cattle in Egypt. The finding of the same two dominant IIa and IId C. parvum subtypes recently found in humans in Egypt suggests calves can be potential reservoirs of zoonotic cryptosporidiosis. |
Occurrence of human-pathogenic Enterocytozoon bieneusi, Giardia duodenalis and Cryptosporidium genotypes in laboratory macaques in Guangxi, China
Ye J , Xiao L , Li J , Huang W , Amer SE , Guo Y , Roellig D , Feng Y . Parasitol Int 2013 63 (1) 132-7 Captive nonhuman primates have been identified as common hosts of Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium hominis, and Cyclospora spp., thus are potential reservoirs of some enteric parasites in humans. However, few studies have examined the source and human-infective potential of enteric parasites in laboratory nonhuman primates. In the present work, 205 fecal specimens were collected from three groups of captive Macaca fascicularis kept in different densities in a laboratory animal facility in Guangxi, China, and examined by PCR for E. bieneusi, G. duodenalis, Cryptosporidium spp., and Cyclospora spp. The infection rates of E. bieneusi and G. duodenalis were 11.3% and 1.2% in Group 1 (young animals kept individually; n=168), 72.2% and 11.1% in Group 2 (young animals kept in groups; n=18), and 31.6% and 5.3% in Group 3 (adults kept in groups; n=19), respectively. Sequence analysis of PCR products showed the presence of five E. bieneusi genotypes, with genotype D (in 16/36 genotyped specimens) and a new genotype (in 15/36 genotyped specimens) as the dominant genotypes. All five E. bieneusi genotypes belonged to the zoonotic group (Group 1). The G. duodenalis genotypes (assemblages AII and B) in five specimens and C. hominis subtype (IdA14) in one specimen were also known human-pathogens, although the Cyclospora seen in one animal appeared to be unique to macaque monkeys. The higher infection rate in younger animals reared in groups and common occurrence of zoonotic genotypes indicated that human-pathogenic E. bieneusi could be transmitted efficiently in captive nonhuman primates, and group-housing was a risk factor for transmission of zoonotic pathogens in young nonhuman primates in research facilities. |
Identity and public health potential of Cryptosporidium spp. in water buffalo calves in Egypt
Amer S , Zidan S , Feng Y , Adamu H , Li N , Xiao L . Vet Parasitol 2012 191 123-7 Little is known about the diversity and public health significance of Cryptosporidium species in water buffaloes. In this study, we examined the distribution of Cryptosporidium spp. in water buffalo calves in Egypt. Rectal fecal specimens from 179 calves and 359 adults were screened microscopically for Cryptosporidium oocysts using modified Ziehl-Neelsen stain. Cryptosporidium spp. in 17 microscopy-positive specimens from calves were genotyped by DNA sequence analysis of the small-subunit rRNA gene, and Cryptosporidium parvum was subtyped by sequence analysis of the 60kDa glycoprotein gene. Cryptosporidium ryanae was found in 10 specimens and C. parvum in 7 specimens, with the former belonging to the newly identified C. ryanae buffalo variant and the latter belonging to the subtypes IIdA20G1 (in 5 specimens) and IIaA15G1R1 (in 2 specimens). The prevailing occurrence of C. ryanae and the subtype family IId of C. parvum and the absence of C. bovis and C. andersoni represent some features of Cryptosporidium transmission in water buffaloes in Egypt. |
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