Cyclospora cayetanensis. NB Cyclospora ooquiste tinción ácido alcohol resistente Cyclospora autofluorescencia. MORFOLOGÍA. Cryptosporidium cayetanensis, Diarrhea, High, Long Giardia lamblia, and Cyclospora cayetanensis from Human Stool Samples[The. Cyclospora cayetanensisUn protista del filo Apicomplexa que causa la enfermedad de mayor relación morfológica y molecular con Cyclospora cayetanensis.
|Published (Last):||7 June 2013|
|PDF File Size:||6.6 Mb|
|ePub File Size:||3.87 Mb|
|Price:||Free* [*Free Regsitration Required]|
Waterborne ctclospora and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment.
These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms.
Quantitative microbial risk assessment QMRA is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred morfplogia recent years.
This review also focuses in the main molecular techniques for cyclosporx of waterborne pathogens and the use of QMRA approach to protect public health. Waterborne disease is a global burden which is estimated to cause more than 2.
It is suggested that waterborne diseases have an economic cost associated of 1 billion dollars annually only in the United States [ 3 ]. Worldwide, an economic loss of nearly 12 billion US dollars per year is estimated [ 4 ]. Waterborne infections are caused by ingestion, airborne or contact with contaminated water by moefologia variety of infectious agents which includes bacteria, viruses, protozoa and helminths [ 5 ].
About million people do not have access to a purified water source, and an estimated 2. It is estimated that 3. Thus, there is an urgent need to undertake cyclosporaa possible efforts to reach this goal.
Even though waterborne outbreaks WBDOs have been morfo,ogia dramatically since the s, the global burden of infectious waterborne disease is still considerable. Moreover, the numbers of outbreaks underestimate the real incidence of waterborne diseases [ 5 ].
Waterborne Pathogens: Detection Methods and Challenges
From toat least outbreaks were associated with drinking water. From toWBDOs andillnesses, associated with the protozoan agents CrytosporidiumNaegleria fowleriGiardiaand the bacteria Salmonella typhimuriumVibrio choleraeLegionellaEscherichia coli O In the period of to21 outbreaks and cases of waterborne disease involving water not intended for dinking were reported.
The etiologic agents were G. H7 and Pseudomonas aeruginosa that resulted in acute gastrointestinal illness, acute respiratory illness, hepatitis, dermatitis and several deaths [ 11 ]. Inan outbreak in Walkerton, Ontario was linked to the presence of E. H7 in the Great Lakes area which resulted in illness cases [ 12 ]. From toLegionella spp. Between andrecreational water-associated outbreaks pools and interactive fountains were cyclopora by 38 States morfoolgia USA and Puerto Rico.
These caused at least 13, cases including 81 outbreaks of acute gastrointestinal illness 12, cases24 of dermatologic illnesses, and 17 were of acute respiratory illness. The leading etiologic pathogen was Cryptosporidium followed by the bacteria E. H7, Shigella sonneiPseudomona s spp. In the Philippines, cholera is an endemic disease; it is estimated that 42, cases of cholera have occurred from to [ 14 ]. Inseveral outbreaks in Haiti and countries devastated by an earthquake including Dominican Republic and Florida in USA were reported.
These outbreaks were related to cholera caused by V. The epidemic resulted in around deaths andcholera cases [ 1516 ]. In the same year, around 25 outbreaks associated with drinking water and other non-recreational water were reported in USA.
Among the remaining, the leading etiologic agents were the bacteria Legionella spp. Furthermore, in in Germany, an enteroaggregative Shiga toxin-producing E. H4 was the causative agent of severe cases of acute diarrhea and bloody diarrhea due to the consumption of uncooked sprouts that were irrigated with contaminated mofrologia [ 17 morfopogia.
In18 cases of cholera were reported by European Union EU countries. The United Kingdom reported 12 cases, France reported four cases, and Austria and Sweden all reported one case each.
In the same year, cases of Cryptosporidium were reported in several countries United Kingdom, Ireland, Belgium and Germany largely due to C. Additionally, 10 waterborne outbreaks were reported in EU during caused by E.
Cyclospora cayetanensis by Nancy Lilibeth Brito Gomez on Prezi
Multiple factors produce outbreaks. The infrastructure, chemical coat of pipes and the architecture of the systems could enhance or inhibit the growth of microorganisms even as microbial communities in drinking water systems leading to outbreaks. Breaks or leaks could lead to low pressure events and when repaired pathogens could enter into the systems [ 319 ]. These failures have been led to outbreaks caused by SalmonellaCampylobacterShigellaE. H7, CryptosporidiumGiardia and Norovirus [ 1920 ].
The weather is another key factor that contributes to outbreaks, since it introduces contaminants into water sources by runoff from either a heavy rainfall or flooding. Moreover, changes in temperature can alter the dynamic of microbes in pipes since planktonic microorganisms may become trapped into biofilms, while pathogens on biofilm may be released in flowing water [ 3 ].
Overall, the morbidity and mortality caused by contaminated water are enormous and need to be controlled by improving the security of drinking water [ 78 ]. In recent years, there have been numerous research advances in methods for detection and characterization of pathogens in water.
Detection methods play a major role in monitoring water quality, surveillance, and quantitative microbial risk assessment; thus, have a major influence on implementing the best practices to mitigate and prevent threats that allow achieving the goal of water safety. This review focuses on the new detection methods, principally in molecular methods for detection of waterborne pathogens as well as the use of QMRA to prevent the presence of pathogens in water.
Waterborne pathogens have appeared again and again for a number reasons including: In developing countries, the lack of financial and technological resources contributes to WBDOs [ 3 ]. Currently, it is estimated that there are species of pathogens infecting humans, which includes bacteria speciesviruses typesparasitic protozoa 57 speciesand several fungi and helminths species [ 223 ]. The development of a disease, when and if infection to the host is produced, depends on factors such as minimal infectious dose MIDpathogenicity, host susceptibility and environmental characteristics.
Enteric bacteria have a MID in the range of 10 7 to 10 8 cells but it is much lower with some species, such as Shigella spp.
Moreover, protozoan only need a few oocysts 10 1 —10 2 to produce the disease as well as the viruses which a small number of these are enough to develop a disease [ 2 ]. The protozoa Microsporidia, as the bacteria Mycobacterium avium intracellulareHelicobacter pyloriTsukamurellaCystoisospora belli and viruses such as adenoviruses, parvoviruses, coronaviruses SARSand polyomavirus are some examples of the emerging potential waterborne pathogens [ 2224 ].
Furthermore, most of cayetanenxis organisms appear to have certain resistance against chlorine such as the microsporidia, Enterocytozoon bienusiEncephalitozoon hellem and E.
The major pathogens microorganisms in drinking water systems and their related diseases are listed in Table 1. Presently, there is no unified method to encompass the collection and analysis of a water sample for all pathogenic microorganisms of interest [ 25 ]. The challenges of the detection methods are the physical differences between the major pathogen groups, low concentration of pathogens in a large volume of water which usually requires enrichment and concentration of the samples prior to detection processing, the presence of inhibitors from the sample especially if it comes from polluted waterestablished general protocols for sample collection, culture-independent detection method, as well as detection of the host origin of pathogens [ 25 ].
The most important requirements for reliable analysis include: Even though culture dependent methods are extensively used for pathogens detection in water, these methods are limited by their low cycoospora and the excessive time needed to obtain reliable results. Furthermore, since there is a broad environmental distribution of human pathogens that exist in a viable but non-culturable VBNC state such as E.
In both culture and molecular methods, index pathogens for monitoring water quality have been morfoloia in order to indicate the presence of a large amount of pathogens in water. Thus, water characterized as pathogen-free by monitoring E.
Molecular methods can be very specific for particular species and provide further phylogenetic information about pathogens [ 32 ]. These methods allow the use of alternatives indicators which easily relate with the host source.
This permits the discrimination between human and animal pathogens and tracking the source of pollution [ 2931 ]. It has been suggested that host—origin libraries, based on a phenotypic methods, may be useful for tracking the pathogen source but the development of such libraries may incur a significant cost [ 8 ].
Therefore, molecular methods seem to better suited for health risk assessments.
Nowadays, there are a number of different molecular methods to detect diverse pathogens. They are used to evaluate the microbiological quality of water, the efficiency of pathogens removal in drinking and wastewater treatment plants, and as microbial source-tracking MST tools [ 33 ].
Several examples of detection methods and their limits of detection are listed in Table 2. Molecular techniques, cayeranensis as nucleic acid amplification procedures, offer sensitive and analytical tools for detecting a variety of pathogens, including new emerging strains, present the possibility of automation, and real-time analysis to provide information for microbial risk assessment purposes [ 33 ].
Polymerase chain reaction PCR is one of the most commonly used molecular-based methods for detection of waterborne pathogens [ 28 ]. PCR operates by amplifying a specific target DNA sequence in a cyclic three-step process—denaturalization, annealing and extension—in order to achieve exponential amplification of morfologiia target sequence [ 63 ].
Several variations of PCR such as multiplex PCR mPCR allow simultaneous detection of several target organisms by coding specific genes of diverse pathogens in the sample in a single reaction.
PCR method has the advantage of quick analysis. However, cayetxnensis necessitates accurate primers and optimal reaction mixture to avoid the risk of false positive and negative results [ 2833 ]. Limitations of DNA based methods such as PCR include the inability to discriminate between viable from non-viable cells that both contain DNA, the low concentration of several pathogens in water such as CryptosporidiumGiardia and viruses, and the lack of data to indicate the real infectious risk to a population.
Challenges of molecular techniques include: Cyclospoar addition, result morfo,ogia is required, since as indicated by Hartman and co-workers [ 64 ]; also, high sensitivity in molecular techniques introduces a high risk of false positive results.
An example of mPCR includes the technique developed by Omar and Barnard [ 65 ] to detect the pathogenic and commensal E. To distinguish pathogenic E. In addition, as control to evaluate the sensitivity of the technique and the false negative due to PCR, inhibitors were controlled using mdh gene malate dehydrogenase and gapdh gene glyceraldehydephosphate dehydrogenase.
This method provides high sensitivity and specificity, faster rate of detection, minimizes the risk of cross-contamination, and there is no need for a post-PCR analysis [ 67 ]. The dual-labeled fluorescent probes such as TaqMan probe and the fluorescent dye Cayetanensia green are the most used techniques for detecting pathogens [ 68 ]. H7 [ 69 ], and Campylobacter spp. These qPCR systems can specifically detect and quantify pathogens at concentrations as low as one target molecule per reaction.
However, most of these methods can only detect and quantify one pathogen in a single reaction [ 71 ]. Other advances in PCR include the microfluidics and nanobiotechnology field, allowing the construction of high-density and low-volume qPCR platforms, such as the OpenArray system that accommodates reactions per array [ 72 ].
For detection of G. Moreover, because of the importance of biofilm coating pipes in drinking water systems, the detection of pathogens in microbial communities is important. For RNA virus detection, quantitative reverse-transcriptase qRT -PCR was developed in order to provide quantitative estimation of the concentration of pathogens in water [ 74 ].
This technique has the advantages of detecting viable cells due to detect messenger RNA mRNAwhich is present only in viable organisms. However, damaged genomes may fail to be detected with this technique [ 3275 ]. Oligonucleotide microarrays are a powerful genomic technology that is widely utilized to monitor gene expression under different cell growth conditions, detecting specific mutations in DNA sequences and characterizing microorganisms in environmental samples [ 76 ].