Comparison of the complete filtration method using an automated feces analyzer with three manual methods for stool examinations.

Conventional diagnostic techniques using manual methods for stool examination have important limitations. Hence there is a need for improved technologies in routine clinical practice. This study aimed to compare detection rates, agreements, and diagnostic performances for stool examinations in all parameters of the complete filtration method using the Sciendox Feces Analysis System-50 automated feces analyzer with three manual methods, the direct smear, Kato's thick smear, and formalin ethyl concentration techniques. The 252 routine stool samples were examined for parasites, white blood cells (WBCs), red blood cells (RBCs), fat globules, and yeast cells using the four methods indicated above, and the complete filtration detection rates, Cohen's kappa (κ), and diagnostic performances were evaluated and compared. The detection rates of RBCs, fat globules, and yeast cells examined by the complete filtration automated method were comparable to the manual methods, but the detection rates of parasites and WBCs were significantly lower. Most methods detected the same seven parasite species, Ascaris lumbricoides, hookworm, Trichuris trichiura, Strongyloides stercoralis, Entamoeba histolytica/dispar, Blastocystis spp., and Giardia intestinalis. Pairwise agreements between the complete filtration and other methods were good to very good for all parameters showing κ values of 0.74 to 0.89. The diagnostic performances against the combined results showed complete filtration method sensitivities of 70%, 81.82%, 77.27%, 100%, and 95% for parasites, WBCs, RBCs, fat globules, and yeast cells, respectively, while the complete filtration negative predictive values (NPVs) and accuracies showed higher than 95% for all parameters. The complete filtration method using the automated feces analyzer showed high NPVs and accuracies, and good agreements with the three tested manual methods for stool examination in all parameters.

Improved diagnosis of gastrointestinal infections using a semi-automated multiplex real-time PCR for detection of enteropathogens.

Introduction. The identification of enteropathogens is critical for the clinical management of patients with suspected gastrointestinal infection. The FLOW multiplex PCR system (FMPS) is a semi-automated platform (FLOW System, Roche) for multiplex real-time PCR analysis.Hypothesis/Gap Statement. FMPS has greater sensitivity for the detection of enteric pathogens than standard methods such as culture, biochemical identification, immunochromatography or microscopic examination.Aim.The diagnostic performance of the FMPS was evaluated and compared to that of traditional microbiological procedures.Methodology. A total of 10 659 samples were collected and analysed over a period of 7 years. From 2013 to 2018 (every July to September), samples were processed using standard microbiological culture methods. In 2019, the FMPS was implemented using real-time PCR to detect the following enteropathogens: Shigella spp., Salmonella spp., Campylobacter spp., Giardia intestinalis, Entamoeba histolytica, Blastocystis hominis, Cryptosporidum spp., Dientamoeba fragilis, adenovirus, norovirus and rotavirus. Standard microbiological culture methods (2013-2018) included stool culture, microscopy and immunochromatography.Results. A total of 1078 stool samples were analysed prospectively using the FMPS from July to September (2019): bacterial, parasitic and viral pathogens were identified in 15.3, 9.71 and 5.29 % of cases, respectively. During the same period of 6 years (2013-2018), the proportion of positive identifications using standard microbiological methods from 2013 to 2018 was significantly lower. A major significant recovery improvement was observed for all bacteria species tested: Shigella spp./enteroinvasive Escherichia coli (EIEC) (P <0.05), Salmonella spp. (P <0.05) and Campylobacter spp. (P <0.05). Marked differences were also observed for the parasites G. intestinalis, Cryptosporidium spp. and D. fragilis.Conclusion. These results support the value of multiplex real-time PCR analysis for the detection of enteric pathogens in laboratory diagnosis with outstanding performance in identifying labile micro-organisms. The identification of unsuspected micro-organisms for less specific clinical presentations may also impact on clinical practice and help optimize patient management.

Prevalence of Intestinal Parasite Infections and Their Associated Factors among Food Handlers Working in Selected Catering Establishments from Bule Hora, Ethiopia.

Intestinal parasites are responsible for one of the major health problems like food contamination with socioeconomic effects in the world with a prevalence rate of 30-60%, in developing countries that lie within tropical and subtropical areas. They pose a reasonable public health burden, particularly in low- and middle-income countries, including Ethiopia. Globally, due to intestinal parasitic infections, around 3.5 billion people are affected and more than 200,000 deaths are reported annually. Around 50000 deaths yearly are caused by intestinal parasites in Ethiopia. As such, intestinal parasites perceived global and local burdens to various countries. The risk of food contamination depends largely on the health status of the food handlers, their hygiene, knowledge, and practice of food hygiene. Food handlers with poor personal hygiene and sanitation conditions are the major potential sources of intestinal helminthes and protozoa worldwide. The proposed study was aimed at evaluating prevalence of intestinal parasitic infections and their associated factors among food handlers working in selected catering establishments. A cross-sectional study was conducted in Bule Hora Town from March to April 2020. A total of 136 catering establishments were selected using a systematic sampling technique. Data analysis was done using SPSS version 20. The prevalence of intestinal parasites in this study was 46.3%. Entamoeba histolytica was the most predominant parasite (33.3%, i.e., 21/63) while Giardia lamblia was the least (11.1%, i.e., 7/63). Consumption of vended or borehole water and hygienic practices such as hand washing before eating, after using toilet, before cooking and trimming of finger nail and wearing proper working clothes and shoes were statistically significant with intestinal parasitic infection (P < 0.05). Generally, the prevalence of intestinal parasitic infection in this study was high and contributed by low socioeconomic status and poor environmental and personal hygiene. Measures including education on personal hygiene, environmental sanitation, drinking water supply, regular medical checkups, and treatment should be taken into account to reduce the prevalence of intestinal parasites.

Effect of magnetic field on the growth of the cultured Entamoeba histolytica isolated from patients in Palestine.

Static magnetic field (SMF) is generated in vicinity of moving charge or current passing through conductor. In this study, we aimed to investigate the effect of SMF on the growth of the cultured Entamoeba histolytica (E. histolytica) trophozoites. Different SMF strengths with maximum value equals 30 mT (mT) was applied on the E.histolytica for different periods of times: 0 h, 24 h, 48 h, and 72 h. A modified diphasic liver infusion agar medium was used for culturing E. histolytica in vitro. The results showed the successful stabilization of culture of E. histolytica trophozoites. If we kept the sample for longer time, e. g. 14 days, the growth rate decreases to zero. When applying 10 mT and 15 mT SMF on the sample, it is found that the cultivated E. histolytica trophozoites dies after 4 and 2 days respectively. The experiments suggested that the SMF inhibited the growth and the propagation of E. histolytica cells. In addition, it completely killed all the cells in a short time interval which depend on the SMF strength. It is concluded that the SMFs inhibits the growth of E. histolytica and change the morphology of these cells. Thus, we recommend to use SMF as treatment to mitigate the growth of E. histolytica.

The epidemiology of amoebiasis in Thi-Qar Province, Iraq (2015-2020): differentiation of Entamoeba histolytica and Entamoeba dispar using nested and real-time polymerase chain reaction.

OBJECTIVES: The objective of this study was to evaluate the present status of amoebiasis in Thi-Qar Province in southern Iraq, and to determine the presence of Entamoeba histolytica and Entamoeba dispar with nested and real-time polymerase chain reaction (PCR). METHODS: Epidemiological data were obtained from the public health department of the Thi-Qar Health Office (2015-2020). Eighty stool samples were also randomly collected from patients ≤12 year of age with diarrhea at 2 hospitals between the beginning of February 2020 and the end of October 2020. These samples were selected after microscopy to identify the 18S rRNA gene in Entamoeba DNA. RESULTS: Of the 341,554 cases of intestinal parasitic infections, 38,004 (11.1%) individuals were recorded as having amoebiasis, which accounted for the highest proportion of infections in 2015 (26.1%) and the lowest in 2020 (8.1%). Amoebiasis was distributed among all age groups, with the age group of 5-14 years accounting for the highest proportion (27.3%). In molecular testing, 42 (52.5%) out of 80 samples were positive for the 18S rRNA gene (888 bp). Using nested PCR, E. histolytica (439 bp) was detected in 25 (31.3%) samples and E. dispar (174 bp) in 14 (17.5%), while using real-time PCR, E. histolytica and E. dispar were detected in 28 (35.0%) and 15 (18.8%) samples, respectively. CONCLUSIONS: Epidemiological data confirmed that amoebiasis is endemic in this province, and is not limited to certain months. Our study confirms the applicability of molecular identification to detect pathogenic and non-pathogenic Entamoeba to prescribe the appropriate drug.

Analysis of D-A locus of tRNA-linked short tandem repeats reveals transmission of Entamoeba histolytica and E. dispar among students in the Thai-Myanmar border region of northwest Thailand.

Intestinal parasitic infections, including those caused by Entamoeba species, are a persistent problem in rural areas of Thailand. The aims of this study were to identify pathogenic Entamoeba species and to analyze their genotypic diversity. Stool samples were collected from 1,233 students of three schools located in the Thai-Myanmar border region of Tak Province, Thailand. The prevalence of Entamoeba infection was measured by polymerase chain reaction (PCR) using species-specific primers. Thirty-one (2.5%) positive cases were detected for E. histolytica, 55 (4.5%) for E. dispar, and 271 (22.0%) for E. coli. Positive samples for E. histolytica and E. dispar were exclusively obtained from a few school classes, whereas E. coli was detected in all grades. No infections caused by E. moshkovskii, E. nuttalli, E. chattoni, and E. polecki were detected in the students studied. The D-A locus of tRNA-linked short tandem repeats was analyzed in samples of E. histolytica (n = 13) and E. dispar (n = 47) to investigate their diversity and potential modes of transmission. Five genotypes of E. histolytica and 13 genotypes of E. dispar were identified. Sequences of the D-A were divergent, but several unique genotypes were significantly prevalent in limited classes, indicating that intra-classroom transmission has occurred. As it was unlikely that infection would have been limited within school classes if the mode of transmission of E. histolytica and E. dispar had been through the intake of contaminated drinking water or food, these results suggest a direct or indirect person-to-person transmission mode within school classes. Positive rates for three Entamoeba species were 2-fold higher in students who had siblings in the schools than in those without siblings, suggesting that transmission occurred even at home due to heavy contacts among siblings.

Diagnosis of intestinal protozoan infections in patients in Cuba by microscopy and molecular methods: advantages and disadvantages.

Microscopy is the gold standard for diagnosis of intestinal parasitic diseases in many countries, including Cuba, although molecular approaches often have higher sensitivity as well as other advantages. Fecal samples from 133 patients were analyzed by light microscopy and also real-time multiplex qPCR targeting Giardia duodenalis, Cryptosporidium spp., and Entamoeba histolytica, and, separately, Dientamoeba fragilis. Microscopy revealed G. duodenalis occurred most commonly (17 patients), followed by Blastocystis spp. (12 patients). In a few patients, Entamoeba histolytica/E. dispar, Cryptosporidium spp., and Cyclospora cayetanensis were identified. Molecular analysis identified 4 more G. duodenalis infections and 2 more Cryptosporidium spp. infections; concordance between microscopy and PCR showed almost perfect agreement for G. duodenalis (κ = 0.88) and substantial agreement for Cryptosporidium (κ = 0.74). PCR indicated that E. dispar, rather than E. histolytica, had been identified by microscopy. Additionally, 16 D. fragilis infections were detected using molecular methods. Although both microscopy and molecular techniques have a place in parasitology diagnostics, for parasites such as D. fragilis, where microscopy can underestimate occurrence, molecular techniques may be preferable, and also essential for distinguishing between morphologically similar microorganisms such as E. histolytica and E. dispar. Although in resource-constrained countries such as Cuba, microscopy is extremely important as a diagnostic tool for intestinal parasites, inclusion of molecular techniques could be invaluable for selected protozoa.

Case report: multiple and atypical amoebic cerebral abscesses resistant to treatment.

BACKGROUND: The parasite Entamoeba histolytica is the causal agent of amoebiasis, a worldwide emerging disease. Amebic brain abscess is a form of invasive amebiasis that is both rare and frequently lethal. This condition always begins with the infection of the colon by E. histolytica trophozoites, which subsequently travel through the bloodstream to extraintestinal tissues. CASE PRESENTATION: We report a case of a 71-year-old female who reported an altered state of consciousness, disorientation, sleepiness and memory loss. She had no history of hepatic or intestinal amoebiasis. A preliminary diagnosis of colloidal vesicular phase neurocysticercosis was made based on nuclear magnetic resonance imaging (NMRI). A postsurgery immunofluorescence study was positive for the 140 kDa fibronectin receptor of E. histolytica, although a serum analysis by ELISA was negative for IgG antibodies against this parasite. A specific E. histolytica 128 bp rRNA gene was identified by PCR in biopsy tissue. The final diagnosis was cerebral amoebiasis. The patient underwent neurosurgery to eliminate amoebic abscesses and was then given a regimen of metronidazole, ceftriaxone and dexamethasone for 4 weeks after the neurosurgery. However, a rapid decline in her condition led to death. CONCLUSIONS: The present case of an individual with a rare form of cerebral amoebiasis highlights the importance of performing immunofluorescence, NMRI and PCR if a patient has brain abscess and a poorly defined diagnosis. Moreover, the administration of corticosteroids to such patients can often lead to a rapid decline in their condition.

Evaluation of Giardia intestinalis, Entamoeba histolytica and Cryptosporidium hominis/Cryptosporidium parvum in human stool samples by the BD MAXTM Enteric Parasite Panel.

Although the microscopic examination of stool samples remains the reference method of choice for the diagnosis of intestinal protistan infections, this method is time-consuming and requires experienced and well-trained operators. The purpose of this study was to evaluate the level of agreement between the BD MAX TM Enteric Parasite Panel (EPP) and microscopy for the detection of Giardia intestinalis (Lambl, 1859), Cryptosporidium spp. and Entamoeba histolytica Schaudinn, 1903 in stool samples. The study included faecal samples of 362 patients who were admitted to our hospital due to gastrointestinal complaints. In the microscopic examination, which was made with the native-lugol method on the stool samples that were taken from the patients, cysts, trophozoites and eggs of the parasite were examined. The diagnosis of G. intestinalis, Cryptosporidium parvum Tyzzer, 1912 and Cryptosporidium hominis Morgan-Ryan, Fall, Ward, Hijjawi, Sulaiman, Fayer, Thompson, Olson, Lal et Xiao, 2002, and E. histolytica was made in the faecal samples using the EPP assay. In the microscopic examination, Cryptosporidium spp. positive stool samples were stained with kinyoun's acid-fast. In the microscopic examination, parasites were detected in 41 (11%) of the 362 stool samples. In contrast, EPP assay identified parasites in 23 (6.3%) of the samples. In the microscopic examination, E. histolytica and Entamoeba dispar Brumpt, 1925 were detected in 22 (6.1%) of the samples, G. intestinalis was seen in 15 (4.1%), and C. parvum or C. hominis were detected in three (0.8%); these values were five (1.4%), 16 (4.4%) and two (0.5%) positive with the EPP assay. Although C. parvum or C. hominis were detected as positive in the microscopic examination of three samples, only two of the samples were positive in both EPP assay and kinyoun's acid-fast method. The EPP assay is a relatively simple test that can distinguish E. histolytica and E. dispar, but it cannot replace microscopy in the diagnosis of amoebiasis. Diagnosis for G. intestinalis and C. parvum/C. hominis with the BD MAXTM enteric parasite panel was equivalent to that with microscopy. We believe that E. histolytica must be diagnosed with nucleic acid amplification tests that have a high sensitivity and specificity like EPP assay in certain patient groups.

Current Status of Amebic Liver Abscess in Korea Comparing with Pyogenic Liver Abscess.

Backgrounds/Aims: With the improvement of hygiene, the incidence of amebic liver abscess is decreasing in South Korea. On the other hand, there is little data on the status of amebic liver abscess compared to pyogenic liver abscess. Methods: Patients with an amebic liver abscess, in whom Entamoeba histolytica (E. histolytica) IgG was positive, were identified retrospectively in a university hospital. The clinical, laboratory, and radiological characteristics of amebic liver abscess were compared with those of pyogenic liver abscess in the same period. Results: Between March 2010 and October 2016, 413 patients with a liver abscess were identified. Among them, the serologic test for E. histolytica was performed in 209 patients. Fifteen (7.2%) were classified as an amebic liver abscess, and the remainder were diagnosed with a pyogenic liver abscess. The age, gender, white blood cell, and CRP was comparable between the two groups. Procalcitonin was lower in amebic liver abscess than the pyogenic one. On CT, peripheral rim enhancement was more frequent, but cluster signs were not observed in amebic liver abscess compared to pyogenic liver abscess. None of the patients with amebic liver abscess died. In contrast, the mortality of pyogenic liver abscess was 4.7%. Conclusions: Amebic liver abscess should still be considered as one of the causes of liver abscess in Korea. It is difficult to discriminate an amebic liver abscess from a pyogenic liver abscess only according to the clinical, laboratory, and radiologic findings. Therefore, it is necessary to perform a serologic test for E. histolytica for a precise evaluation of liver abscess in a high-risk group.

Loop-mediated isothermal amplification (LAMP) reaction as viable PCR substitute for diagnostic applications: a comparative analysis study of LAMP, conventional PCR, nested PCR (nPCR) and real-time PCR (qPCR) based on Entamoeba histolytica DNA derived from faecal sample.

BACKGROUND: This study reports the analytical sensitivity and specificity of a Loop-mediated isothermal amplification (LAMP) and compares its amplification performance with conventional PCR, nested PCR (nPCR) and real-time PCR (qPCR). All the assays demonstrated in this study were developed based on Serine-rich Entamoeba histolytica protein (SREHP) gene as study model. RESULTS: A set of SREHP gene specific LAMP primers were designed for the specific detection of Entamoeba histolytica. This set of primers recorded 100% specificity when it was evaluated against 3 medically important Entamoeba species and 75 other pathogenic microorganisms. These primers were later modified for conventional PCR, nPCR and qPCR applications. Besides, 3 different post-LAMP analyses including agarose gel electrophoresis, nucleic acid lateral flow immunoassay and calcein-manganese dye techniques were used to compare their limit of detection (LoD). One E. histolytica trophozoite was recorded as the LoD for all the 3 post-LAMP analysis methods when tested with E. histolytica DNA extracted from spiked stool samples. In contrast, none of the PCR method outperformed LAMP as both qPCR and nPCR recorded LoD of 100 trophozoites while the LoD of conventional PCR was 1000 trophozoites. CONCLUSIONS: The analytical sensitivity comparison among the conventional PCR, nPCR, qPCR and LAMP reveals that the LAMP outperformed the others in terms of LoD and amplification time. Hence, LAMP is a relevant alternative DNA-based amplification platform for sensitive and specific detection of pathogens.

Distribution of Intestinal Parasites Detected between September 2011-2018 at Dokuz Eylül University Medical Faculty Hospital.

OBJECTIVE: Intestinal parasitic diseases are important public health problems in our country as well as in the world. In this study, intestinal parasites were investigated in patients admitted to Dokuz Eylül University Hospital (DEUH) with various gastrointestinal system complaints. METHODS: Patients (n=18460) who were referred to the DEUH Central Parasitology Laboratory between January 2011 and December 2018, were included in the study. Fecal samples were examined with Nativ-lugol method and then formol ethyl-acetate precipitation method was applied. Trichrome and kinyoun acid-fast stainings were performed on the necessary samples. Demographic data of the patients were obtained from the hospital's and laboratory's information operating system. RESULTS: One or more parasites were detected in 6% (1128) of 18460 patients examined. The mean age of the patients with parasites was 39.7 (±23.1) years, of which 53.3% were male and 47.6% were female. The distribution of parasites detected were as follows; 4.8% (879) Blastocystis hominis, 0.7% (135) amoebas other than Entamoeba histolytica/dispar, 0.4% (70) Giardia intestinalis, 0.3% (49) Enterebius vermicularis, 0.1% (21) Entamoeba histolytica/dispar, and 0.01% (10) other rare parasites. CONCLUSION: Our study shows that intestinal parasitic infections are still an important public health problem in our region and that there is a decrease in their incidence.

Successful surgical drainage with intraoperative ultrasonography for amebic liver abscess refractory to metronidazole and percutaneous drainage: a case report.

BACKGROUND: Metronidazole (MNZ) has been clearly established as a medication for amebic liver abscess. In uncomplicated cases, surgical drainage should be avoided. We report a case of amebic liver abscess refractory to MNZ that was successfully treated using preoperative computed tomography (CT) and percutaneous and surgical drainage with intraoperative ultrasonography (IOUS). CASE PRESENTATION: A 53-year-old man with high-grade fever was diagnosed with a cystic lesion on his right hepatic lobe using CT. Percutaneous drainage was performed, and antibacterial drugs were administered. However, the infection and condition of the patient worsened. Entamoeba histolytica was detected from pus within the mediastinal cavity. Hence, the patient was diagnosed with amebic liver abscess. After the diagnosis was established, we administered MNZ for 10 days. Despite this, the patient's physical condition did not improve. Blood tests suggested impending disseminated intravascular coagulation (DIC). We performed surgical intervention to drain the amebic liver abscess refractory to conservative treatment. During surgery, imaging information from preoperative CT and IOUS enabled us to recognize the anatomical structures and determine the incision lines of the hepatic capsule and hepatic tissue. The patient's DIC immediately regressed after surgery. Unfortunately, malnutrition and disuse syndrome contributed to the patient's long recovery period. He was discharged 137 days post-surgery. CONCLUSIONS: We reported a case of amebic liver abscess refractory to conservative treatment. Surgical drainage with preoperative CT and IOUS allowed us to safely and effectively perform complex abscess decompression.

Intestinal parasitosis, anaemia and risk factors among pre-school children in Tigray region, northern Ethiopia.

BACKGROUND: Intestinal parasitic infections (IPIs) and anaemia are major health problems. This study assessed the prevalence of intestinal parasitic infections, anaemia and associated factors among pre-school children in rural areas of the Tigray region, northern Ethiopia. METHODS: A community based cross-sectional study was conducted among 610 pre-school children in rural communities of Northern Ethiopia from June 2017 to August 2017. Stool specimens were examined for the presence of trophozoites, cysts, oocysts, and ova using direct, formal-ethyl acetate concentration, Kato-Katz, and Ziehl-Neelsen techniques. Haemoglobin was measured using a HemoCue spectrometer. RESULTS: Among the 610 participating pre-school children in the study, the prevalence of IPIs and anaemia were 58% (95% conference interval (CI): 54.1-61.9%) and 21.6% (95% CI: 18.5-25.1%), respectively. Single, double, and triple parasitic infections were seen in 249 (41, 95% CI: 37-45%), 83 (14, 95% CI: 11-17%), and 22 (3.6, 95% CI: 2.4-5.4%) children, respectively. Of the seven intestinal parasitic organisms recorded from the participants, Entamoeba histolytica/dispar was the most prevalent 220 (36.1%) followed by Giardia lamblia 128 (20.1%), and Hymenolepis nana 102 (16.7%). Mixed infections were common among G. lamblia, E. histolytica/dispar and Cryptosporidium spp. oocyst. Intestinal parasitic infection prevalence increased from 47% in children aged 6-11 months to 66% in those aged 48-59 months; the prevalence ratio (PR) associated with a one-year increase in age was 1.08 (95% CI: 1.02-1.14, p = 0.009). Age-adjusted prevalence was higher in children who had been dewormed (PR = 1.2; 95% CI: 1.00-1.4, p = 0.045), and lower in households having two or more children aged under five (PR = 0.76, 95% CI: 0.61-0.95, p = 0.015). Anaemia rose from 28% in children aged 6-11 months to 43% in those aged 12-23 months, then fell continuously with age, reaching 7% in those aged 48-59 months. Age adjusted, anaemia was more prevalent in households using proper disposal of solid waste (PR = 1.5, 95% CI: 0.1-2.10, p = 0.009) while eating raw meat (PR = 0.49, 95% CI: 0.45-0.54, p = 0.000), any maternal education (PR = 0.64 95% CI: 0.52-0.79, p = 0.000), and household water treatment (PR = 0.75, 95% CI: 0.56-1.0, p = 0.044) were associated with lower prevalence of anaemia. CONCLUSIONS: More than half of the children were infected with intestinal parasites, while anaemia prevalence was concentrated in the 12-23 month age group. This study has identified a number of potentially modifiable risk factors to address the significant prevalence of IPIs and anaemia in these children. Improvements in sanitation, clean water, hand hygiene, maternal education could address both short and long-term consequences of these conditions in this vulnerable population.

Bacterial Superinfection of Amoebic Liver Abscess.

A 78-year-old male, originally from China, was brought to the hospital for weakness, urinary incontinence, confusion, and poor oral intake. He was started on empiric antibiotics, which were narrowed when blood cultures produced gram-negative bacteremia speciating to Klebsiella pneumoniae, sensitive to ceftriaxone. Computed tomography scan of the abdomen and pelvis demonstrated a large cystic region with air-fluid level in the left lobe of the liver. Suspecting this to be the source of the patient's bacteremia, the lesion was percutaneously drained and the fluid cultured, which also revealed ceftriaxone-sensitive Klebsiella pneumoniae. While a stool ova and parasite examination on the patient was negative, further workup was positive for Entamoeba histolytica antibody in the serum, detected via enzyme-linked immunosorbent assay and indicative of either current or past infection. This suggested possible prolonged subclinical infection with bacterial superinfection, especially given that Klebsiella pneumoniae is one of the most common organisms cultured from these abscesses. In patients with liver abscesses who immigrated from developing and/or endemic regions or have a relevant recent travel history, an underlying amoebic etiology of an abscess should be considered.

Genetic variability of E. histolytica strains based on the polymorphism of the SREHP gene using nested PCR-RFLP in Erbil, North Iraq.

E. histolytica is an intestinal parasite that causes asymptomatic infection mostly; however, it may also cause amoebic dysentery and liver abscess. Molecular identification is required in epidemiological studies due to the presence of morphologically identical nonpathogenic species. Therefore, this study was conducted to first evaluate the prevalence rate of E. histolytica among symptomatic individuals of Erbil city, and to investigate the genetic diversity of the parasite in a limited geographic area. Accordingly, a total of 2026 samples were examined microscopically, and confirmed by nested PCR for 18s rRNA gene. The results showed that the prevalence rate of E. histolytica was 1.97% (40 samples) among symptomatic patients. The SREHP gene was used as a marker to show the genetic polymorphism of E. histolytica; however, to compare the genetic diversity of symptomatic with asymptomatic isolates, 57 asymptomatic samples were obtained from our previous study. The amplified products of the SREHP gene were digested by AluI endonuclease, and DNA banding patterns were analysed. Results showed 29 different DNA patterns among the 97 symptomatic and asymptomatic samples, 62 of which shared similar DNA patterns. However, 8 different DNA patterns were observed among asymptomatic samples, whereas 15 distinct patterns were observed among symptomatic isolates. In conclusion, this study found that the prevalence rate of E. histolytica was relatively low; relatively high genetic diversity was observed in a restricted endemic area; with higher rates of variability in symptomatic rather than in asymptomatic isolates, indicating a possible correlation between the genotype of E. histolytica and their clinical outcome.