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排序方式: 共有1023条查询结果,搜索用时 19 毫秒
991.
KHAIRALLAH A.S. MOHAMMED ZAHRAA H. ABDULKAREEM AYOOB R. ALZAALAN AMEL K. YAQOOB 《Polish journal of microbiology》2021,70(1):79
Methicillin-resistant Staphylococcus aureus (MRSA) is notorious as a hospital superbug and a problematic pathogen among communities. The incidence of MRSA has substantially increased over time in Iraq. The aim of this study was to determine the prevalence and spa types of MRSA isolates from outpatients or patients upon admission into hospitals. Various biochemical tests identified S. aureus isolates, and then this identification was confirmed by PCR using species-specific 16S rRNA primer pairs. Antibiotic susceptibility was determined against methicillin, oxacillin, and vancomycin using the disk diffusion method. Vancomycin MIC was detected by VITEK 2 compact system. All the identified isolates were screened for the presence of mecA and lukS-PV-lukF-PV genes; 36 of them were subjected to spa typing-based PCR. Out of 290 clinical samples, 65 (22.4%) were S. aureus, of which 62 (95.4%) strains were resistant to oxacillin and methicillin. Except for two isolates, all MRSA isolates were mecA positive. One of the three MSSA isolates was mecA positive. Five strains were resistant to vancomycin. Fourteen (21.5%) isolates were positive for the presence of lukS-PV-lukF-PV genes. Spa typing of 36 S. aureus isolates revealed eleven different spa types, t304 (30.3%), t307 (19.4%), t346 (8.3%), t044 (8.3%), t15595 (8.3%), t386 (5.5%), t5475 (5.5%), t17928 (2.8%), t14870 (2.8%), t021 (2.8%), and t024 (2.8%). These findings could be useful for assessing the genetic relatedness of strains in the region for epidemiological and monitoring purposes, which would be essential to limiting the spread of MRSA. 相似文献
992.
Milena S. Blanes Stephen C.M. Tsoi Michael K. Dyck 《Journal of visualized experiments : JoVE》2016,(108)
Research into prenatal programming in the pig has shown that the sex of the developing embryo or fetus can influence the developmental outcome. Therefore, the ability to determine an embryo''s sex is necessary in many experiments particularly regarding early development. The present protocol demonstrates an inexpensive, rapid and non-toxic preparation of pig genomic DNA for use with PCR. Day 30 embryos must be humanely collected according to the guidelines established by Institutional Animal Policy and Welfare Committees for the present protocol. The preparation of the whole embryo for this PCR based sexing technique simply involves grinding the frozen embryo to a fine powder using a pre-chilled mortar and pestle. PCR-quality DNA is released from a small amount of embryo powder by applying a hot incubation in an alkaline lysis reagent. Next, the DNA solution is mixed with neutralization buffer and used directly for PCR. Two primer pairs are generated to detect specific sex determining region of the Y- chromosome (SRY) and ZFX region of the X- chromosome with high accuracy and specificity. The same protocol can be applied to other elongated embryos (Day 10 to Day 14) earlier than Day 30. Also, this protocol can be carried with 96-welled plates when screening a large number of embryos, making it feasible for automation and high-throughput sex typing. 相似文献
993.
Andreas Kuhn 《FEMS microbiology reviews》1995,17(1-2):185-190
Abstract: The membrane insertion of bacteriophage coat proteins occurs independent of the Sec-translocase of Escherichia coli . Detailed study of the Pf3 and M13 coat proteins has elucidated two fundamental mechanisms of how proteins invade the membrane, most likely by direct interaction with the lipid bilayer. The Sec-independent translocation of amino-terminal regions across the inner membrane is limited to a short length and a small number of charged residues. Protein regions that contain several charged residues are efficiently translocated across the membrane when these regions are flanked by two adjacent hydrophobic segments interacting synergistically. The relevance of these findings for the membrane insertion mechanism of multispanning membrane proteins is discussed. 相似文献
994.
Bacteriophage K7 is specific for Escherichia coli strains harbouring R factors of incompatability group W, including hybrid coliphage P1-Myxococcus virescens plasmids. The phage has an unusual morphology with an isometric head and long tail of variable length. The tail lengths appear to fall into classes corresponsing to simple multimers of a unit length. Partially purified lysates of the phage include material that may represent phage particles in the process of biogenesis and other material demonstrating attachment of phage to cell envelope. Newly released phage DNA contains single standed ends. In the course of work, E. coli strains that harbour R factor Sa were found to be apparently restrictive. 相似文献
995.
Deborah Harvey Carolyn Harrington Michael W. Heuzenroeder Christopher Murray 《FEMS microbiology letters》1993,108(3):291-295
Abstract A phage typing system using a group of 11 closely related phage (as judged by Southern analysis and restriction fragment length polymorphism analysis) was able to distinguish at least six phage types in Salmonella heidelberg of human and animal origin. Restriction fragment length polymorphism analysis using cosmid probes from S. heidelberg confirmed that most S. heidelberg isolates belong to a single 'clonal' group. Southern analysis using DNA isolated from each of the testing phage group showed that phage types 4, 5 and 6 carry closely related endogenous or lysogenic phage. Induction of a lysogenic phage Hlp-4 (Heidelberg lysogenic phage) from type 4 could become lysogenic and convert phage types 1 and 3 to phage type 4 and phage type 5 to a non-typable phenotype. 相似文献
996.
L L Nesse 《Animal genetics》1990,21(3):303-311
Goat alloantisera and bovine blood typing reagents were used to characterize eight erythrocyte antigen specificities in Norwegian goats by cluster analysis, absorption and family studies. Most of the goat sera were produced by injecting dams once or twice with blood cells or blood from their own kids. The characterized specificities were designated N1-N8. The two specificities N5 and N8 were recognized both by goat alloantisera and by reagents against the bovine factors E'1 and E'2 (N5) and I (N8), which are allelic factors in the bovine B-system. In goat families, the two specificities also behaved as alleles. Consequently, the locus or gene system coding for these specificities was called the B-system of goats. The six other erythrocyte antigens were provisionally assigned to six separate loci. In addition, a bovine anti-sheep R factor reagent reacted with cells from 3.3% of the goats tested, whereas a monoclonal antibody against the Forssman antigen reacted with all the goats tested. 相似文献
997.
《Fungal Ecology》2017
Knowledge of the environmental prevalence of members of the Cryptococcus neoformans/Cryptococcus gattii species complex is important, since cryptococcal infection is acquired from the environment. We determined whether trees located in two South African recreational areas harboured pathogenic cryptococci and compared the isolates to clinical isolates obtained from Western Cape hospitals with molecular typing techniques. The majority of isolates originating from trees in a public park in Cape Town (PPCT) were C. gattii sensu stricto, followed by C. neoformans sensu stricto genotype AFLP1/VNI. The PPCT trees might be a source of infection, since all genotype AFLP1/VNI isolates from these trees and one clinical isolate belonged to the same sequence type (ST), i.e. ST23. Recombination and basidiospore production might be occurring in PPCT trees that contained C. gattii s.s. isolates belonging to both mating types. The presence of C. gattii s.s. in PPCT trees might therefore pose a risk to human health. 相似文献
998.
《Journal of molecular biology》2023,435(7):167974
CRISPR-Cas are prokaryotic defence systems that provide protection against invasion by mobile genetic elements (MGE), including bacteriophages. MGE can overcome CRISPR-Cas defences by encoding anti-CRISPR (Acr) proteins. These proteins are produced in the early stages of the infection and inhibit the CRISPR-Cas machinery to allow phage replication. While research on Acr has mainly focused on their discovery, structure and mode of action, and their applications in biotechnology, the impact of Acr on the ecology of MGE as well as on the coevolution with their bacterial hosts only begins to be unravelled. In this review, we summarise our current understanding on the distribution of anti-CRISPR genes in MGE, the ecology of phages encoding Acr, and their coevolution with bacterial defence mechanisms. We highlight the need to use more diverse and complex experimental models to better understand the impact of anti-CRISPR in MGE-host interactions. 相似文献
999.
M. Saifi M.R. Pourshafie M.M. Soltan Dallal M. Katouli 《Letters in applied microbiology》2009,49(2):160-165
Aims: Clonality among high-level gentamicin-resistant Enterococcus faecium (HLGR-EF) isolates obtained from clinical and sewage treatment plants (STP) were investigated using PhePlate system (PhP), ribotyping and pulsed-field gel electrophoresis (PFGE).
Methods and Results: During 1 year study (September 2005–2006), a total of 106 HLGR-EF isolates were collected from clinical ( n = 48) and STP ( n = 58) samples in Tehran, Iran. Biochemical fingerprinting of these isolates using the PhP showed the presence of 21 PhP types (diversity index, Di = 0·97) among the clinical and 21 PhP types ( Di = 0·91) among the STP isolates. Representative isolates of each PhP type ( n = 42) were further characterized by the ribotyping method. Sixteen ribotypes were identified among the isolates with five types shared between the clinical and STP isolates. PFGE recognized 24 clonal types among these isolates with three pulsotypes shared between the clinical and STP isolates. Combination of the two techniques (PFGE and ribotyping) resulted in 24 ( Di = 0·96) and 16 ( Di = 0·93) types among the strains isolated from clinical and STP samples, respectively.
Conclusions: We concluded that the combination of PhP typing, ribotyping and PFGE could be extremely discriminatory when examining HLGR-EF isolates.
Significance and Impact of the Study: The emergence of highly diverse HLGR-EF population in Iran is of serious concern especially because of their multi-resistances. 相似文献
Methods and Results: During 1 year study (September 2005–2006), a total of 106 HLGR-EF isolates were collected from clinical ( n = 48) and STP ( n = 58) samples in Tehran, Iran. Biochemical fingerprinting of these isolates using the PhP showed the presence of 21 PhP types (diversity index, Di = 0·97) among the clinical and 21 PhP types ( Di = 0·91) among the STP isolates. Representative isolates of each PhP type ( n = 42) were further characterized by the ribotyping method. Sixteen ribotypes were identified among the isolates with five types shared between the clinical and STP isolates. PFGE recognized 24 clonal types among these isolates with three pulsotypes shared between the clinical and STP isolates. Combination of the two techniques (PFGE and ribotyping) resulted in 24 ( Di = 0·96) and 16 ( Di = 0·93) types among the strains isolated from clinical and STP samples, respectively.
Conclusions: We concluded that the combination of PhP typing, ribotyping and PFGE could be extremely discriminatory when examining HLGR-EF isolates.
Significance and Impact of the Study: The emergence of highly diverse HLGR-EF population in Iran is of serious concern especially because of their multi-resistances. 相似文献
1000.
S. Parthiban Hirak Kumar Mukhopadhyay D. Panneer P. X. Antony R. M. Pillai 《Indian journal of microbiology》2011,51(4):456-460
A total of 128 faecal samples/rectal swabs were collected from dogs showing signs of diarrhea/enteritis in and around Puducherry,
South India. Eighteen clinical samples, showing high HA titre of 1:512 and above and positivity by polymerase chain reaction
(PCR) with CPV-2ab primers, were subjected to virus isolation in CRFK cell line. Of the 18 samples processed, 3 samples (16.6%)
were positive for CPV and were confirmed by haemagglutination, dot-ELISA, and IFAT. The three cell culture isolates were characterized
as CPV-2b types by multiplex PCR as well as by monoclonal antibody typing. 相似文献