Last data update: Apr 18, 2025. (Total: 49119 publications since 2009)
Records 1-10 (of 10 Records) |
Query Trace: Mull B[original query] |
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Diagnostic evaluation of fatal Balamuthia mandrillaris meningoencephalitis in a captive Bornean orangutan (Pongo pygmaeus) with identification of potential environmental source and evidence of chronic exposure
Hawkins SJ , Struthers JD , Phair K , Ali IKM , Roy S , Mull B , West G . Primates 2020 62 (1) 51-61 A female Bornean orangutan (Pongo pygmaeus) aged 11 years and 6 months was examined by veterinarians after caretakers observed lethargy and facial grimacing. Within 72 h the primate had left-sided hemiparesis that worsened over the next week. An MRI revealed a focal right-sided cerebral mass suspected to be a neoplasm. Ten days after onset of clinical signs, the orangutan died. On postmortem exam, the medial right parietal lobe was replaced by a 7 × 4 × 3.5 cm focus of neuromalacia and hemorrhage that displaced the lateral ventricle and abutted the corpus callosum. Histopathology of the cerebral lesion revealed pyogranulomatous meningoencephalitis with intralesional amoeba trophozoites and rare cysts. Fresh parietal lobe was submitted to the Centers for Disease Control and Prevention lab for multiplex free-living amoebae real-time PCR and detected Balamuthia mandrillaris DNA at a high burden. Mitochondrial DNA was sequenced, and a 760-bp locus 19443F/20251R was compared to several human infections of B. mandrillaris and shown to be identical to the isolates from four human cases of encephalitis: 1998 in Australia, 1999 in California, 2000 in New York, and 2010 in Arizona. Indirect immunofluorescent antibody testing of stored serum samples indicated exposure to B. mandrillaris for at least 2 years prior to death. Within 1 week of the orangutan's death, water from the exhibit was analyzed and identified the presence of B. mandrillaris DNA, elucidating a possible source of exposure. B. mandrillaris, first reported in a mandrill in 1986, has since occurred in humans and animals and is now considered an important emerging pathogen. |
Assessment of drinking water sold from private sector kiosks in post-earthquake Port-au-Prince, Haiti
Patrick M , Steenland M , Dismer A , Pierre-Louis J , Murphy JL , Kahler A , Mull B , Etheart MD , Rossignol E , Boncy J , Hill V , Handzel T . Am J Trop Med Hyg 2017 97 84-91 Consumption of drinking water from private vendors has increased considerably in Port-au-Prince, Haiti, in recent decades. A major type of vendor is private kiosks, advertising reverse osmosis-treated water for sale by volume. To describe the scale and geographical distribution of private kiosks in metropolitan Port-au-Prince, an inventory of private kiosks was conducted from July to August 2013. Coordinates of kiosks were recorded with global positioning system units and a brief questionnaire was administered with the operator to document key kiosk characteristics. To assess the quality of water originating from private kiosks, water quality analyses were also conducted on a sample of those inventoried as well as from the major provider company sites. The parameters tested were Escherichia coli, free chlorine residual, pH, turbidity, and total dissolved solids. More than 1,300 kiosks were inventoried, the majority of which were franchises of four large provider companies. Approximately half of kiosks reported opening within 12 months of the date of the inventory. The kiosk treatment chain and sales price was consistent among a majority of the kiosks. Of the 757 kiosks sampled for water quality, 90.9% of samples met World Health Organization (WHO) microbiological guideline at the point of sale for nondetectable E. coli in a 100-mL sample. Of the eight provider company sites tested, all samples met the WHO microbiological guideline. Because of the increasing role of the private sector in drinking water provision in Port-au-Prince and elsewhere in Haiti, this assessment was an important first step for government regulation of this sector. |
Real-time PCR and Sequencing Assays for Rapid Detection and Identification of Avian Schistosomes in Environmental Samples.
Narayanan J , Mull BJ , Brant SV , Loker ES , Collinson J , Secor WE , Hill VR . Appl Environ Microbiol 2015 81 (12) 4207-15 ![]() ![]() Cercarial dermatitis, also known as swimmer's itch, is an allergenic skin reaction followed by intense itching caused by schistosome cercariae penetrating human skin. Cercarial dermatitis outbreaks occur globally, and are frequently associated with fresh water lakes and occasionally with marine or estuarine waters where year-round or migratory birds reside. In this study, a broadly reactive TaqMan assay was developed targeting 18S ribosomal RNA (rDNA) gene sequences based on a genetically diverse panel of schistosome isolates representing 13 genera and 20 species. A PCR assay was also developed to amplify a 28S ribosomal RNA (rDNA) gene region for subsequent sequencing to identify schistosomes. When applied to surface water samples seeded with Schistosoma mansoni cercariae, the 18S TaqMan assay enabled detection at a level of 5 S. mansoni cercariae in 100 L of lake water. The 18S TaqMan and 28S PCR-sequencing assays were also applied to 100-L water samples collected from lakes in Nebraska and Wisconsin where there were reported dermatitis outbreaks. Avian schistosome DNA was detected in 11 of 34 lake water samples using the TaqMan assay. Further 28S sequence analysis of positive samples confirmed the presence, and provided preliminary identification of avian schistosomes in ten of the 11 samples. These data indicate that the broadly schistosome-reactive TaqMan assay can be effective for rapid screening of large-volume water samples for detection of avian schistosomes, thereby facilitating timely response actions to mitigate or prevent dermatitis outbreaks. Additionally, samples positive by the 18S TaqMan assay can be further assayed using the 28S sequencing assay to both to confirm the presence of schistosomes and contribute to their identification. |
Comparison of real-time PCR methods for the detection of Naegleria fowleri in surface water and sediment
Streby A , Mull BJ , Levy K , Hill VR . Parasitol Res 2015 114 (5) 1739-46 ![]() Naegleria fowleri is a thermophilic free-living ameba found in freshwater environments worldwide. It is the cause of a rare but potentially fatal disease in humans known as primary amebic meningoencephalitis. Established N. fowleri detection methods rely on conventional culture techniques and morphological examination followed by molecular testing. Multiple alternative real-time PCR assays have been published for rapid detection of Naegleria spp. and N. fowleri. Foursuch assays were evaluated for the detection of N. fowleri from surface water and sediment. The assays were compared for thermodynamic stability, analytical sensitivity and specificity, detection limits, humic acid inhibition effects, and performance with seeded environmental matrices. Twenty-one ameba isolates were included in the DNA panel used for analytical sensitivity and specificity analyses. N. fowleri genotypes I and III were used for method performance testing. Two of the real-time PCR assays were determined to yield similar performance data for specificity and sensitivity for detecting N. fowleri in environmental matrices. |
The first association of a primary amebic meningoencephalitis death with culturable Naegleria fowleri in tap water from a U.S. treated public drinking water system
Cope JR , Ratard RC , Hill VR , Sokol T , Causey JJ , Yoder JS , Mirani G , Mull B , Mukerjee KA , Narayanan J , Doucet M , Qvarnstrom Y , Poole CN , Akingbola OA , Ritter J , Xiong Z , da Silva A , Roellig D , Van Dyke R , Stern H , Xiao L , Beach MJ . Clin Infect Dis 2015 60 (8) e36-42 BACKGROUND: Naegleria fowleri is a climate-sensitive, thermophilic ameba found in warm, freshwater lakes and rivers. Primary amebic meningoencephalitis (PAM), which is almost universally fatal, occurs when N. fowleri-containing water enters the nose, typically during swimming, and N. fowleri migrates to the brain via the olfactory nerve. In August 2013, a 4-year-old child died of meningoencephalitis of unknown etiology in a Louisiana hospital. METHODS: Clinical and environmental testing and a case investigation were initiated to determine the cause of death and to identify potential exposures. RESULTS: Based on testing of CSF and brain specimens, the child was diagnosed with PAM. His only reported water exposure was tap water; in particular, tap water that was used to supply water to a lawn water slide on which the child had played extensively prior to becoming ill. Water samples were collected from both the home and the water distribution system that supplied the home and tested; N. fowleri were identified in water samples from both the home and the water distribution system. CONCLUSIONS: This case is the first reported PAM death associated with culturable N. fowleri in tap water from a U.S. treated drinking water system. This case occurred in the context of an expanding geographic range for PAM beyond southern tier states with recent case reports from Minnesota, Kansas, and Indiana. This case also highlights the role of adequate disinfection throughout drinking water distribution systems and the importance of maintaining vigilance when operating drinking water systems using source waters with elevated temperatures. |
Environmental surveillance for toxigenic Vibrio cholerae in surface waters of Haiti.
Kahler AM , Haley BJ , Chen A , Mull BJ , Tarr CL , Turnsek M , Katz LS , Humphrys MS , Derado G , Freeman N , Boncy J , Colwell RR , Huq A , Hill VR . Am J Trop Med Hyg 2014 92 (1) 118-25 ![]() Epidemic cholera was reported in Haiti in 2010, with no information available on the occurrence or geographic distribution of toxigenic Vibrio cholerae in Haitian waters. In a series of field visits conducted in Haiti between 2011 and 2013, water and plankton samples were collected at 19 sites. Vibrio cholerae was detected using culture, polymerase chain reaction, and direct viable count methods (DFA-DVC). Cholera toxin genes were detected by polymerase chain reaction in broth enrichments of samples collected in all visits except March 2012. Toxigenic V. cholerae was isolated from river water in 2011 and 2013. Whole genome sequencing revealed that these isolates were a match to the outbreak strain. The DFA-DVC tests were positive for V. cholerae O1 in plankton samples collected from multiple sites. Results of this survey show that toxigenic V. cholerae could be recovered from surface waters in Haiti more than 2 years after the onset of the epidemic. |
Improved method for the detection and quantification of Naegleria fowleri in water and sediment using immunomagnetic separation and real-time PCR
Mull BJ , Narayanan J , Hill VR . J Parasitol Res 2013 2013 608367 Primary amebic meningoencephalitis (PAM) is a rare and typically fatal infection caused by the thermophilic free-living ameba, Naegleria fowleri. In 2010, the first confirmed case of PAM acquired in Minnesota highlighted the need for improved detection and quantification methods in order to study the changing ecology of N. fowleri and to evaluate potential risk factors for increased exposure. An immunomagnetic separation (IMS) procedure and real-time PCR TaqMan assay were developed to recover and quantify N. fowleri in water and sediment samples. When one liter of lake water was seeded with N. fowleri strain CDC:V212, the method had an average recovery of 46% and detection limit of 14 amebas per liter of water. The method was then applied to sediment and water samples with unknown N. fowleri concentrations, resulting in positive direct detections by real-time PCR in 3 out of 16 samples and confirmation of N. fowleri culture in 6 of 16 samples. This study has resulted in a new method for detection and quantification of N. fowleri in water and sediment that should be a useful tool to facilitate studies of the physical, chemical, and biological factors associated with the presence and dynamics of N. fowleri in environmental systems. |
Recovery of diverse microbes in high turbidity surface water samples using dead-end ultrafiltration
Mull B , Hill VR . J Microbiol Methods 2012 91 (3) 429-33 Dead-end ultrafiltration (DEUF) has been reported to be a simple, field-deployable technique for recovering bacteria, viruses, and parasites from large-volume water samples for water quality testing and waterborne disease investigations. While DEUF has been reported for application to water samples having relatively low turbidity, little information is available regarding recovery efficiencies for this technique when applied to sampling turbid water samples such as those commonly found in lakes and rivers. This study evaluated the effectiveness of a DEUF technique for recovering MS2 bacteriophage, enterococci, Escherichia coli, Clostridium perfringens, and Cryptosporidium parvum oocysts in surface water samples having elevated turbidity. Average recovery efficiencies for each study microbe across all turbidity ranges were: MS2 (66%), C. parvum (49%), enterococci (85%), E. coli (81%), and C. perfringens (63%). The recovery efficiencies for MS2 and C. perfringens exhibited an inversely proportional relationship with turbidity, however no significant differences in recovery were observed for C. parvum, enterococci, or E. coli. Although ultrafilter clogging was observed, the DEUF method was able to process 100-Liter surface water samples at each turbidity level within 60minutes. This study supports the use of the DEUF method for recovering a wide array of microbes in large-volume surface water samples having medium to high turbidity. |
Primary amebic meningoencephalitis deaths associated with sinus irrigation using contaminated tap water
Yoder JS , Straif-Bourgeois S , Roy SL , Moore TA , Visvesvara GS , Ratard RC , Hill VR , Wilson JD , Linscott AJ , Crager R , Kozak NA , Sriram R , Narayanan J , Mull B , Kahler AM , Schneeberger C , da Silva AJ , Poudel M , Baumgarten KL , Xiao L , Beach MJ . Clin Infect Dis 2012 55 (9) e79-85 BACKGROUND: Naegleria fowleri is a climate-sensitive, thermophilic ameba found in the environment, including warm, freshwater lakes and rivers. Primary amebic meningoencephalitis (PAM), which is almost universally fatal, occurs when N. fowleri-containing water enters the nose, typically during swimming, and N. fowleri migrates to the brain via the olfactory nerve. In 2011, 2 adults died in Louisiana hospitals of infectious meningoencephalitis after brief illnesses. METHODS: Clinical and environmental testing and case investigations were initiated to determine the cause of death and to identify the exposures. RESULTS: Both patients had diagnoses of PAM. Their only reported water exposures were tap water used for household activities, including regular sinus irrigation with neti pots. Water samples, tap swab samples, and neti pots were collected from both households and tested; N. fowleri were identified in water samples from both homes. CONCLUSIONS: These are the first reported PAM cases in the United States associated with the presence of N. fowleri in household plumbing served by treated municipal water supplies and the first reports of PAM potentially associated with the use of a nasal irrigation device. These cases occurred in the context of an expanding geographic range for PAM beyond southern tier states with recent case reports from Minnesota, Kansas, and Virginia. These infections introduce an additional consideration for physicians recommending nasal irrigation and demonstrate the importance of using appropriate water (distilled, boiled, filtered) for nasal irrigation. Furthermore, the changing epidemiology of PAM highlights the importance of raising awareness about this disease among physicians treating persons showing meningitislike symptoms. |
Detection of GI and GII noroviruses in ground water using ultrafiltration and TaqMan real-time RT-PCR
Hill VR , Mull B , Jothikumar N , Ferdinand K , Vinje J . Food Environ Virol 2010 2 (4) 218-224 Noroviruses (NoVs) are a leading cause of epidemic and sporadic acute gastrointestinal illness globally. These viruses can potentially contaminate rural private wells and non-community drinking water systems, and cause waterborne disease outbreaks related to consumption of contaminated ground water. Detection of NoVs in water samples can be challenging because they are genetically and antigenically diverse, and noncultivable. In the present study, the detection limits of a novel broadly reactive GI assay and an existing GII NoV real-time TaqMan reverse transcriptase-polymerase chain reaction (RT-qPCR) assay in ground water concentrates was determined. Ground water samples (50 l) from two sources (Lawrenceville, GA and Gainesville, FL, USA) were seeded with electron microscopy-enumerated and RT-qPCR quantified NoV and concentrated using hollow-fiber ultrafiltration (UF) followed by either polyethylene glycol (PEG) precipitation or microconcentrators. Detection limits for GI NoV ranged from 1 x 10^4 (GA source) to 2 x 10^5 (FL source) virus particles in 50 l water samples (corresponding to 200-3,000 particles/l) and 5 x 10^4 (GA source) to 5 x 10^5 (FL source) virus particles (corresponding to 1,000-10,000 particles/l) for GII NoV. The reported UF method, sample processing procedures, and RT-qPCR assays should be effective tools for sensitive detection of NoVs in large-volume water samples. 2010 Springer Science+Business Media, LLC (outside the USA). |
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