Agar plates are the standard solid support material for growing microorganisms. The extent of bacterial activity in a given sample in a definite set of conditions mainly depends on the total number of bacteria present in it irrespective of their species. How to optimize the drop plate method for enumerating. Sterilize the surface of the containers by wiping them with 7095% alcohol or soaking. Baermann and koga agar plate method, but these are rarely employed in epidemiologic studies. Preparation of culture media, agar plates, antibiotics and general necessities 2. To ascertain the current status of strongyloidiasis in mothers and their preschool children, a fieldbased survey was conducted in western uganda using a combination of diagnostic methods. Koga agar plate culture and polymerase chain reaction for detection of human strongyloides stercoralis infection in maluku, indonesia. Plate count agarstandard methods agar tryptone glucose yeast agar intended use plate count agar and standard methods agar plate count. An evaluation of the agar plate method for the detection of.
With this method, a small amount of sample is placed on the agar plate either with a swab, or as a drop from an inoculating loop if the sample is a liquid. High prevalence of strongyloides stercoralis among school. The drop plate method has some advantages over the spread plate sp method. On solid media, a single microbe will grow and divide to produce a colony, a spot of identical descendants.
In this method, fixed amount of inoculum generally 1 ml from a brothsample is placed in the center of sterile petri dish using a sterile pipette. After incubation of the agar plate, colonies can be counted and identified. The realtime polymerasechain reaction rtpcr is a novel, promising diagnostic method, that detects the dna of the parasite in stool samples. Usually by the third or fourth quadrant only a few organisms are transferred on the inoculating loop and these produce a few isolated colonies. Koga agar plate culture and baermann method for the diagnosis of s. Diagnostic methods for strongyloides stercoralis detection during 20002005. Comparison of the quantitative formalin ethyl acetate. We prepare agar media either by mixing 1 to 2% agar with individual. Plate count agarstandard methods agar tryptone glucose. A perfect spread plate technique will results visible and isolated colonies of bacteria that are evenly distributed in the plate and are countable. The prevalence of other soiltransmitted helminthiasis and intestinal schistosomiasis were also determined.
The agar plate method is a new technique with high detection rates for coprological diagnosis. Agar plates are petri dishes containing agar in combination with a growth medium to culture microorganisms such as bacteria. Prevalence and risk factors of strongyloides stercoralis. Microbes in action this material may be duplicated by teachers for use in the classroom. Pdf comparing diagnostic accuracy of katokatz, koga.
Spread plate technique is a method employed to plate a liquid sample for the purpose of isolating or counting the bacteria present in that sample. Sterile molten agar is added to these plates and plates are rotated gently to ensure uniform mixing of the sample with agar. Diagnostic comparison of baermann funnel, koga agar plate. A modified formalinether concentration technique for. Value of the agar plate method for the diagnosis of. Filter paper discs approximately 6mm in diameter were soaked with 15l of the plant extract and placed in the previously prepared agar plates. Our goal was to determine whether there was diagnostic agreement between an inhouse pcr and two microscopic techniques, the baermann funnel bm and the koga agar plate culture kap for the detection of s. Comparison of the flotac400 dual technique and the formalin. The koga agar plate technique allows direct observation of s. All stool samples were examined with standard methods katokatz, baermann, and koga agar plate 14, 18, 22 for soiltransmitted helminths, including strongyloides stercoralis, and for s. A retrospective study comparing agar plate culture. The principle behind this technique is that when fresh stool is incubated on the. Save some of your budget money by preparing your own nutrient agar plates.
Different agar plates are available from emsl analytical. This method commonly uses an andersen n6 type impactor e. Comparing diagnostic accuracy of katokatz, koga agar plate. Plate drying, method of storage and storage time should be determined by individual. Pdf comparing diagnostic accuracy of katokatz, koga agar. A retrospective study comparing agar plate culture, indirect. The koga agar plate method was\ud the most accurate diagnostic assay for s. The agar plate method was found to be more sensitive than baermanns standard method, which had not been previously studied. A crosssectional study was carried out between january and april 2011 among 2,861 participants living in 60 villages of takeo province, using koga agar plate culture, the baermann technique and the katokatz technique on a single stool sample. The efficacy of agar plate culture has been evaluated for the detection of strongyloides stercoralis and hookworm, compared with direct smear, the formalinether sedimentation technique and the filterpaper method. A number of techniques have been developed to recognize larvae of strongyloides stercoralis in stool samples, including direct smear of faeces.
The koga agar plate method was the most accurate diagnostic assay for s. Detection of bacterial contamination by agar plate test. Modified agar plate culture method for culture of strongyloides stercoralis. The koga agar plate culture is a technique for the detection of helminth larvae. Label the bottom of the petri plate with the name of the microorganism and the date. The agar plate culture alone or combined with other techniques detected. Koga k, kasuya s, khamboonruang c, sukhavat k, ieda m, takatsuka n, et al. The quantitative formalin ethyl acetate concentration technique qfec was compared to agar plate culture apc for the detection of strongyloides stercoralis larvae. Use the lid of the petri dish to protect the agar from aerial contamination. Comparing diagnostic accuracy of katokatz, koga agar plate, etherconcentration, and flotac for schistosoma mansoni and soiltransmitted helminths. As the original sample is diluted by streaking it over successive quadrants, the number of organisms decreases. Stool examination is not a sufficiently accurate tool for followup either, and at the least the baermann method and koga agar plate culture should be used to confirm response to treatment, when serology is not available. Novel approaches to the diagnosis of strongyloides.
As depicted in figure 1, each fresh stool sample was subjected to the katokatz method 3 thick smears, the koga agar plate method 1 examination, and the flotac dual technique 1 examination, fresh stool sample homogenized in saf. Author summaryan estimated 30 million to 100 million people are infected with the parasitic worm strongyloides stercoralis, the causative agent of strongyloidiasis, and yet this is a neglected tropical disease. Preparation of culture media, agar plates, antibiotics and. Available formats pdf please select a format to send. Hold the inoculating loop with your thumb and first two fingers. The minimum concentrations of the plant extracts to. Agar is a gelatinous polymer substance derived from red algae and commonly used in a biological laboratory setting as a substrate. Sterile technique it is very important in microbiology to work with pure cultures. Plate count agar is also suitable for enumerating bacterial count of sterile rooms. In this method a small volume of a dilution of phage suspension and a small quantity of host cells grown to high cell density, sufficient to give 10 710 8 cfuml, are mixed in about 2. After planting initial microorganisms on the gelatinous surface of the plate, researchers. Pdf modified agar plate culture method for culture of. Applying the koga agar plate kap culture method and microscopy examination of stool samples collected from 60 roma and 21 nonroma children, no.
Agar method agar is an alternative substrate to paper, particularly for testing germination in small and mediumsized seeds. Improved detection of strongyloides stercoralis in modified agar. Less time and effort are required to dispense the drops onto an agar plate than to spread an equivalent total sample volume into the agar. The koga agar plate culture method is recognized in most studies as being the most sensitive coprological method for the detection of strongyloides larvae. Koga k, kasuya s, khamboonruang c, sukhavat k, nakamura y, tani s, ieda m, tomita k, tomita s, hattan n, mori m, makino s. Methods manual applied microbiology rice university. Comparing diagnostic accuracy of katokatz, koga agar. Streaking microbial cultures on agar plates, page 2 1999 science in the real world. An evaluation of the agar plate method for the detection of strongyloides stercoralis in northen thailand. The efficacy of agarplate culture has been evaluated for the detection of strongyloides stercoralis and hookworm, compared with direct smear, the formalinether sedimentation technique and the filterpaper method. Of 1085 stool samples from the routine laboratory service at king chulalongkom memorial hospital in bangkok, 241 samples harboured s. The petri dishes are incubated in the laboratory so the organisms impacted on the plate can grow. The helminth was found with the agar plate method in 23 samples 69.
A modification of koga agar plate culture was performed, consisting of a 2. A particle distribution grid can also be used to help determine when a contamination event occurred. Overall, 251 school children were screened for strongyloides stercoralis by using either the baermann method, or the koga agar plate method, or both techniques. Alternativemethods,fromserologytomolecularbiology,have been developed and evaluated during the past few years 14. A comparative study was carried out to evaluate the strongyloides stercoralis infections in children and dogs inside and outside the segregated settlement in medzev, eastern slovakia, and a survey of the soil within the settlement was included. Sufficiently large stool samples were preserved in 5% formaldehyde and subjected to the flotac400 dual technique and the fect to i. Anamnart et al modified formalinether concentration for diagnosis of human strongyloidiasis 745 3. Prevalence and risk factors of strongyloides stercoralis in. Strongyloides stercoralis, diagnosis, laboratory techniques and procedures. With the streak plate procedure, a mixture of cells is spread over the surface of a semisolid, agar based nutrient medium in a petri dish such that fewer and fewer bacterial cells are deposited at widely separated points on the surface of the medium and, following incubation, develop into colonies. Pour plate method is usually the method of choice for counting the number of colonyforming bacteria present in a liquid specimen.
Bsac disc diffusion method for antimicrobial susceptibility testing. According to a standard operating procedure of the baermann technique, a lemonsized fecal sample. We made a prospective study, to test the efficacy of the agar plate technique to detect s. Stool examination is not a sufficiently accurate tool for followup either, and at the least the baermann method and koga agar plate culture should be used to confirm response to treatment, when serology is. Pdf a number of techniques have been developed to recognize. Thus, studies are needed in which highly sensitive diagnostic techniquessuch as circulating cathodic antigen and circulating anodic antigen tests for s mansoni and s haematobium, and koga agar plate culture, the baermann method, pcr, or elisa for s stercolarisare used, to give a more comprehensive picture of the prevalence of these. Form fdancims 2400a standard plate count and coliform plate count rev. Place the culture you wish to transfer near the sterile petri plate of nutrient agar. In this retrospective study, we compared the sensitivity of agar plate coproculture apc, an inhouse immunofluorescence test ifat and an inhouse rtpcr for the diagnosis of s. Microbial growth media contains nutrients and an energy source to fuel the microbes as they grow, and agar to keep the media in a semisolid, gellike state. To enumerate bacteria present in a sample by serial dilution agar plating method or total plate count tpc method. The diagnostic accuracy of four copromicroscopic techniques i.
Moreover, our study confirms that flotac is a sensitive technique for detection of common soiltransmitted helminths. A modified agar plate method for detection of strongyloides stercoralis. Comparison of the flotac400 dual technique and the. Bsac disc diffusion method for antimicrobial susceptibility. Strongyloides stercoralis is a soiltransmitted helminth, but it has a unique life cycle that can be completed in the human host, in a process known as autoinfection worldwide, the burden of disease is substantial 300400 million infections. Tryptone glucose yeast agar are used for obtaining microbial plate counts from milk and dairy products, foods, water and other materials of sanitary importance. Plate drying, method of storage and storage time should be determined by individual laboratories as part of their quality assurance programme. Larvae are best visualized following recovery by the baermann funnel sedimentation technique or after culture using koga agar plate, charcoal culture or the haradamori filter paper technique. Koga k, kasuya s, khamboonruang c, sukhavat k, ieda m, takatsuka n, kita k, ohtomo h 1991. Bacteria present in a sample by serial dilution agar plating. We compared the agar plate culture method, for the diagnosis of s. Modified agar plate culture method for culture of strongyloides. Strongyloidiasis is mainly prevalent in the tropics and subtropics, but there is as yet no global public health strategy. The drop plate dp method can be used to determine the number of viable suspended bacteria in a known beaker volume.
Occurrence of strongyloides stercoralis in yunnan province. The baermann method and koga agar plate culture apc are preferable, although they are cumbersome and not routinely used. The poured plate count method is preferred to the surface inoculation method, since it gives higher results. Polymerase chain reaction pcr assays have been developed, yet conflicting results have been reported. Jul 20, 2010 as depicted in figure 1, each fresh stool sample was subjected to the katokatz method 3 thick smears, the koga agar plate method 1 examination, and the flotac dual technique 1 examination, fresh stool sample homogenized in saf. With the streakplate procedure, a mixture of cells is spread over the surface of a semisolid, agarbased nutrient medium in a petri dish such that fewer and fewer bacterial cells are deposited at widely separated points on the surface of the medium and, following incubation, develop into colonies. The double agar method as described by adams 1959 is widely used to enumerate phages. It is important to avoid over mixing the soft agar since that could. Agar dissolves slowly in hot water and forms a viscous solution, which forms a stiff jelly upon cooling.
The roundworm strongyloides stercoralis in children, dogs. Plate count agarstandard methods agar tryptone glucose yeast agar intended use plate count agar and standard methods agar plate count agar. When prepared for inoculation, a plate contains solid agar to provide a surface for growth, mixed with nutrient materials. Diagnosis, treatment and risk factors of strongyloides. Evaluation of techniques for the diagnosis of strongyloides. Hold the swab comfortably in one hand and lift the lid of the petri dish with the other. The effect of the sampling effort for multiple stool samples examination on infection prevalence and on the sensitivity of the different diagnostic methods are presented in table 2 for s. The diagnosis of this parasite requires specialized techniques e. Feb 16, 2015 save some of your budget money by preparing your own nutrient agar plates. Muller hinton agar plates were prepared and the test microorganisms were inoculated by the spread plate method.