Environmental Swab Samples Research Articles

Risk factor analysis for Salmonella contamination of broiler chicken (Gallus gallus) hatcheries in Great Britain

Salmonellosis is the second most commonly reported zoonosis in the European Union and contaminated meat from broiler chickens (Gallus gallus) is an important source of human infection. In Great Britain (GB), prevalence of Salmonella enterica in broiler flocks is low, having declined considerably since the introduction of the Salmonella National Control Programme in 2010. However, this decreasing trend has stabilised in recent years and serovars with known ability to persistently colonise hatcheries have been isolated from broiler flocks with increasing frequency, indicating that further controls on hatchery contamination are required. The broiler industry in GB has changed dramatically over the last 15 years, with greater intensification and dominance by a small number of very large companies which rely on relatively few hatcheries. An investigation of risk factors for Salmonella contamination in GB broiler hatcheries was therefore carried out so that relevant up-to-date advice on Salmonella control can be provided. Twenty-two hatcheries, representing most commercial scale GB broiler hatcheries, were visited between 2015 and 2018. Salmonella contamination was comprehensively investigated at each hatchery by collecting between 108 and 421 environmental swab samples per hatchery (6990 samples in total from all hatcheries). An in-depth questionnaire on hatchery operations was completed for each hatchery, and results were incorporated into a risk factor analysis (univariable followed by multivariable mixed effects logistic regression) to identify factors associated with Salmonella occurrence. Overall, 6.0 % (416/6990) of environmental samples were Salmonella-positive and Salmonella was isolated from 17/22 hatcheries. Ten different serovars were isolated, the most common being S. Senftenberg and S. Mbandaka which are known hatchery colonisers. Sixty-four risk factor variables were investigated. Twenty-two of these were initially retained based on univariable analyses (p ≤ 0.25) and six were ultimately left in the final multivariable model (p ≤ 0.05). Salmonella detection was positively associated with having ≥30 hatchers in regular use compared to fewer (Odds ratio [OR] 23.7, 95 % confidence interval [CI] 6.7–84.2), storing trays in process rooms (OR 28.8, CI 7.8–106.3), drying set-up trolleys in corridors (OR 15.6, CI 5.9–41.4) and having skips located in enclosed areas (OR 8.99, CI 5.89–41.35). Using a closed waste disposal system was negatively associated with Salmonella detection (OR 0.08, CI 0.04−0.18) and the odds of detecting Salmonella in hatcheries with 31−60 total workers was lower compared to hatcheries with ≤30 staff (OR 0.16, CI 0.06−0.40). Despite the complexities of hatchery enterprises, changes to a relatively small number of features may significantly reduce the occurrence of hatchery contamination.

Detection of SARS-CoV-2 on Surfaces in Households of Persons with COVID-19.

SARS-CoV-2 transmission from contaminated surfaces, or fomites, has been a concern during the COVID-19 pandemic. Households have been important sites of transmission throughout the COVID-19 pandemic, but there is limited information on SARS-CoV-2 contamination of surfaces in these settings. We describe environmental detection of SARS-CoV-2 in households of persons with COVID-19 to better characterize the potential risks of fomite transmission. Ten households with ≥1 person with laboratory-confirmed COVID-19 and with ≥2 members total were enrolled in Utah, U.S.A. Nasopharyngeal and anterior nasal swabs were collected from members and tested for the presence of SARS-CoV-2 by RT-PCR. Fifteen surfaces were sampled in each household and tested for presence and viability of SARS-CoV-2. SARS-CoV-2 RNA was detected in 23 (15%) of 150 environmental swab samples, most frequently on nightstands (4/6; 67%), pillows (4/23; 17%), and light switches (3/21; 14%). Viable SARS-CoV-2 was cultured from one sample. All households with SARS-CoV-2-positive surfaces had ≥1 person who first tested positive for SARS-CoV-2 ≤ 6 days prior to environmental sampling. SARS-CoV-2 surface contamination occurred early in the course of infection when respiratory transmission is most likely, notably on surfaces in close, prolonged contact with persons with COVID-19. While fomite transmission might be possible, risk is low.

Surveillance of enteric pathogens in imported seafood and environmental surfaces in five seafood markets before the outbreak of COVID-19

To monitor the presence of enteric pathogens in imported seafood, a total of 140 seafood samples imported from eight overseas countries were collected from Beijing, Dalian, Shanghai, Guangzhou, and Wuhan seafood markets from June to November 2019. Additionally, 116 viral, environmental swab samples were also collected from the Wuhan and Guangzhou seafood markets. Five typical enteric bacterial pathogens (Aeromonas spp., Shigella spp., Salmonella spp., Vibrio spp., and Listeria monocytogenes) and four viruses (Rotavirus, Norovirus, Astrovirus, and Sapovirus) were detected positive. Results showed that eight Vibrio parahaemolyticus isolates appeared in seafood imported to Dalian, Wuhan, Shanghai, Guangzhou, and Beijing. In contrast, Vibrio fluvialis and Aeromonas were isolated in another two samples. Norovirus was detected in one oyster sample imported from France and environmental surface in Guangzhou. The remaining pathogens were negative in all the samples being tested. With 120 V. parahaemolyticus isolates from the above countries, the genomic analysis revealed that sequence type ST1152 isolates imported from Canada were clustered with two V. parahaemolyticus isolates from Canada. This study presented the first microbiological analysis of the Wuhan seafood market before the outbreak of COVID-19, which demonstrated that supervision should be strengthened to prevent enteric pathogens via imported seafood.

Environmental surface sampling for qualitative & quantitative detection of microbial burden in high risk areas of three hospitals in Dhaka city

Background and objectives: Acquiring infection from intensive care units & operation theatres is considered as a significant public health problem around the world. Microbial burden may vary across different ICUs and OTs, albeit these sectors remain underexplored especially in resource poor country. Purpose of the study was qualitative and quantitative assessment of microbial burden in ICUs and OTs’ environmental surfaces of three tertiary care hospitals in Dhaka city.
 Materials and methods: The study was conducted in the department of Microbiology, BIRDEM General Hospital. A total 232 environmental surface swab samples & 86 hand & nasal swab samples of ICU staffs were collected from the selected three hospitals. The samples were processed according to standard operating procedures.
 Results: Highest bacterial load from inanimate surface was found on sinks (155 CFU/cm²), ICU bedrails (7.56 ± 0.76 CFU/cm²) and OT sandals (66 CFU/cm²). Pathogenic isolates were found more in ICUs & non-pathogenic isolates were found more in OTs. Among the non-pathogens, Micrococcus spp. (37.8%) and Bacillus spp. (19.8%) were found from OTs. Among the pathogens, Acinetobacter spp. was predominant (21.2%) followed by Pseudomonas spp. (19.2%) in the ICUs. Overall cleanliness & hygiene status of Hospital ‘A’ & ‘C’ were found unacceptable whereas Hospital ‘B’ was found marginally bearable/tolerable.
 Conclusion: It could be inferred from the study that health care workers and environmental surface contaminations with MDR pathogens are a definitive risk factor for the indoor patients. Routine sampling to assess bioburden in high risk areas of hospital should be done regularly for identification & correction of the weakness of ongoing infection control protocol.
 Bangladesh J Med Microbiol 2021; 15 (1): 15-25

Earliest detection to date of SARS-CoV-2 in Florida: Identification together with influenza virus on the main entry door of a university building, February 2020.

In February and March, 2020, environmental surface swab samples were collected from the handle of the main entry door of a major university building in Florida, as part of a pilot surveillance project screening for influenza. Samples were taken at the end of regular classroom hours, between the dates of February 1–5 and February 19-March 4, 2020. Influenza A(H1N1)pdm09 virus was isolated from the door handle on four of the 19 days sampled. Both SARS-CoV-2 and A(H1N1)pdm09 virus were detected in a sample collected on February 21, 2020. Based on sequence analysis, the Florida SARS-CoV-2 strain (designated UF-11) was identical to strains being identified in Washington state during the same time period, while the earliest similar sequences were sampled in China/Hubei between Dec 30th 2019 and Jan 5th 2020. The first human case of COVID-19 was not officially reported in Florida until March 1st. In an analysis of sequences from COVID-19 patients in this region of Florida, there was only limited evidence of subsequent dissemination of the UF-11 strain. Identical or highly similar strains, possibly related through a common transmission chain, were detected with increasing frequency in Washington state between end of February and beginning of March. Our data provide further documentation of the rapid early spread of SARS-CoV-2 and underscore the likelihood that closely related strains were cryptically circulating in multiple U.S. communities before the first “official” cases were recognized.

Cold-chain transportation in the frozen food industry may have caused a recurrence of COVID-19 cases in destination: Successful isolation of SARS-CoV-2 virus from the imported frozen cod package surface

Coronavirus disease 2019 (COVID-19) pandemic has spread in 220 countries/regions to wreak havoc to human beings around the world. At present, the second wave of COVID-19 has begun in many European countries. The complete control of COVID-19 is very urgent. Although China quickly brought the virus under control, there have been eight sporadic outbreaks in China since then. Both in Xinfadi of Beijing and Dalian outbreak of COVID-19, environmental swab samples related to imported cold chain food were tested nucleic acid positive for SARS-CoV-2. In this outbreak in Qingdao, we directly isolated SARS-CoV-2 from the cod outer package's surface swab samples. This is the first time worldwide, SARS-CoV-2 were isolated from the imported frozen cod outer package's surface, which showed that imported frozen food industry could import SARS-CoV-2 virus.

CrAssphage as a Novel Tool to Detect Human Fecal Contamination on Environmental Surfaces and Hands.

CrAssphage is a recently discovered human gut–associated bacteriophage. To validate the potential use of crAssphage for detecting human fecal contamination on environmental surfaces and hands, we tested stool samples (n = 60), hand samples (n = 30), and environmental swab samples (n = 201) from 17 norovirus outbreaks for crAssphage by real-time PCR. In addition, we tested stool samples from healthy persons (n = 173), respiratory samples (n = 113), and animal fecal specimens (n = 68) and further sequenced positive samples. Overall, we detected crAssphage in 71.4% of outbreak stool samples, 48%–68.5% of stool samples from healthy persons, 56.2% of environmental swabs, and 60% of hand rinse samples, but not in human respiratory samples or animal fecal samples. CrAssphage sequences could be grouped into 2 major genetic clusters. Our data suggest that crAssphage could be used to detect human fecal contamination on environmental surfaces and hands.

Distribution of Salmonella serovars and characterization of isolates in cattle feces and environmental samples

In this study, it was aimed to identify the presence of Salmonella serovars, and investigate the antibiotic susceptibility of isolates and the presence of certain virulence factors in the samples collected from cattle feces and environmental samples. Fecal and environmental swab samples were regularly collected from five different dairy cattle farms for a period of one year, once in each season. Totally, 425 fecal samples from animals, 21 of which had diarrhea and 400 environmental samples were examined for Salmonella spp.. While no Salmonella spp. was isolated from the environmental samples, Salmonella spp. was isolated from three (0.36%) of the fecal samples. All isolates were isolated from a single farm and they were sampled in autumn. Two strains were serotyped as S. Kottbus and the other as S. Lindenburg. All serovars were found to be sulfamethoxazole-resistant, while susceptible to cefoxitin, nalidixic acid, trimethoprim-sulfamethoxazole, enrofloxacin, ciprofloxacin, ceftriaxone, ceftiofur and amoxicillin-clavulanic acid. While mgtC, misL and invA were detected in all isolates, no pefA was detected. stn was detected in S. Lindenburg and one of S. Kottbus, whereas the spvA was detected only in S. Lindenburg. Presence of isolation only in one of the five farms and the low isolation rates were associated with a good level of biosecurity measures in the area where the study was conducted. Salmonella spp. isolation from healthy animals apart from animals with diarrhea was found to be important in terms of the role that persistently infected animals can play in the spread of the agent.

An outbreak of norovirus-related acute gastroenteritis associated with delivery food in Guangzhou, southern China

BackgroundA large number of students at a school in Guangzhou city developed a sudden onset of symptoms of diarrhea and vomiting. To help control the outbreak, we conducted an epidemiological investigation to determine the causative agent, sources, role of transmission and risk factors of the infections.MethodsThe study population consisted of probable and confirmed cases. An active search was conducted for cases among all students, teachers and other school staff members. A case control study was carried out using standardized online questionnaires. Data were obtained regarding demographic characteristics, gastrointestinal symptoms, personal hygiene habits, history of contact with a person who had diarrhea and/or vomiting and dining locations during the past 3 days. Rectal swabs or stool samples of the cases and, food handlers, as well as environmental samples were collected to detect potential intestinal viruses and bacteria. We calculated odds ratios and 95% confidence intervals (CIs).ResultsA total of 157 individuals fit the definition of a probable case, including 46 with laboratory-confirmed norovirus infection between March 8 and March 22, 2018. The proportion of students who had eaten delivery food 3 days before the onset of illness in the case group was 2.69 times that in the control group (95%CI: 1.88–3.85). Intake of take-out food 3 days earlier, and exposure to similar cases 72 h before onset and case in the same dormitory were risk factors. A total of 20 rectal swab samples from students, 10 rectal swabs from food handlers and 2 environmental swab samples from the out-campus restauranttested positive for norovirus (GII, genogroup II strain).ConclusionsWe investigated an outbreak of norovirus infectious diarrhea. Food handling practices carry potential risk of acute gastroenteritis outbreaks owing to a lack of surveillance and supervision. Greater attention should be paid to the monitoring and supervision of food handlers in off campus restaurant to reduce the incidence of norovirus-related acute gastroenteritis associated with delivery food.

Assessment of extended-spectrum \u03b2-lactamase (ESBLs) \u2013 producing Escherichia coli from minced meat of cattle and swab samples and hygienic status of meat retailer shops in Jimma town, Southwest Ethiopia

BackgroundThe impact of animals sources of food as a possible reservoir for extended-spectrum β-lactamase (ESBL) - Producing E. coli, and the dissemination of such strains into the food production chain need to be assessed. This study was aimed to assess the presence and antimicrobial susceptibility patterns of ESBLs - producing E. coli isolates from minced meat and environmental swab samples at meat retailer shops of Jimma town, Southwest Ethiopia.MethodologyA cross-sectional descriptive study was conducted from March to June, 2016. A total of 168 minced meat and swab samples were first enriched by buffered peptone water (BPW) for overnight and streaked onto MacConkey agar. Double disk synergy (DDS) method was used for detection of ESBL-producing strains. A disk of amoxicillin + clavulanic acid (20/10 μg) was placed in the center of Mueller-Hinton agar plate, and cefotaxime (30 μg) and ceftazidime (30 μg) were placed at a distance of 20 mm from the central disk. Checklist was used to assess hygienic status of butcher shops and practices meat handlers.ResultsA total of 35 (20.80%) biochemically confirmed E. coli were obtained from 168 samples. Of these, 21 (23.9%) of them were detected from 88 minced meat and the other 14 (17.5%) from 80 swab samples taken from butcher’s hand, knives, chopping board and protective clothing. From 35 E. coli isolates, 7(20%) of them were confirmed as ESBL- producers. Among ESBL- producing strains, 85.7% were resistant for cefotaxime and ceftriaxone and 71.4% for ceftazidime. Among non-ESBLs-producing strains only seven isolates were resistant to third generation cephalosporin. All E. coli isolates were resistant to ampicillin, penicillin and erythromycin, and susceptible to amikacin. Poor hygienic status of butcher shops and unhygienic practice of meat handlers were observed.ConclusionThe detections of ESBLs- producing strains could be contributed for the increment of multi drug resistant isolates. This study also concluded that, unhygienic meat handling and processing practice can contribute for contaminations of meat. Thus, strategies should be planned and implemented to improve the knowledge and practice of butchers about handling and processing of meat.

Improved Positive Predictive Performance of Listeria Indicator Broth: A Sensitive Environmental Screening Test to Identify Presumptively Positive Swab Samples.

PDX-LIB, Listeria Indicator Broth, was developed as a proprietary sensitive screening test to identify presumptively positive environmental swab samples for Listeria sp. The original formulation, while sensitive, initially proved to exhibit acceptable levels of false positive test results. Paradigm Diagnostics has been undertaken to modify the medium formulation to render it more selective while not sacrificing its sensitivity. After identification of a candidate formulation through laboratory studies, a field trial was conducted to validate the test performance parameters, including the true positive frequency and false positive frequency in several different food-processing facilities. Identical swab samples were enriched in both the original medium formulation and the new formulation. Presumptive positive samples were confirmed by plating on selective differential agar and qPCR analysis. The field trial data demonstrate that the new formulation significantly reduces the frequency of false positive samples compared to the original Listeria Indicator Broth formulation, without compromising the sensitivity of the original formulation. The new medium formulation resulted in no false positive samples compared to the 54% increased presumptive positive samples obtained with the original medium formulation.

Genetic Characterization of Fungi Isolated from Environmental Samples: A Molecular Surveillance Study of Public Health Importance.

Background: A multistate fungal meningitis outbreak began in September 2012 that affected 751 individuals who received contaminated spinal injections across 20 states in the United States, which led to 64 deaths. In our previous study, we examined 26 environmental swab samples collected from various locations of the manufacturing premises of the compounding company to determine the possible cause of this outbreak and identified 14 novel species of fungi. Objective: In this follow-up study, a total of 198 environmental surveillance samples were collected and analyzed to detect pathogenic fungal species from other compounding company premises located in three regions of the United States. Methods: DNA sequencing was performed at the large subunit ribosomal RNA (LSU rRNA) and internal transcribed spacer (ITS) regions on the 25 positive fungal isolates. Results: Sequence analysis of the ITS1, the ITS2, and the LSU rRNA regions confirmed the presence of the following fungal species in the samples analyzed: (1) Pestalotiopsis cocculi from the region I; (2) Epicoccum nigrum and Trichaptum biforme from the region I; (3) Nigrospora sphaerica and Fusarium sp. from the region II; and (4) Curvularia sp., Fusarium sp., Penicillium sp., and Preussia sp. from the region III. Conclusions: Our results suggest that the LSU and ITS regions are good genetic markers to perform fungal typing. Highlights: DNA sequencing technology can be used in the implementation of effective environmental monitoring programs of public health importance.

Antibiotic resistance of Escherichia coli isolated from captive Bengal tigers at Safari parks in Bangladesh.

Objectives:The present study was carried out to assess the antibiotic resistance and to identify the resistance genes in Escherichia coli from captive Bengal tigers at two Safari parks in Bangladesh.Materials and Methods:A number of 24 environmental fecal swab samples of Bengal tigers were collected from two different Safari parks in Bangladesh. For the isolation of E. coli, samples were submitted to a number of bacteriological screening and biochemical tests. The antibiotic susceptibility of E. coli isolates was determined by disk diffusion method.Results:Results demonstrated that 18 environmental fecal samples were positive to E. coli in bacteriological screening and biochemical test. The overall prevalence of E. coli in Bengal tiger was 75% (n = 18/24). The antibiogram study unveiled that all the isolates were resistant to ampicillin. Sulfamethoxazole-trimethoprim, nalidixic acid, and tetracycline were 89% (n = 16/18) resistant. On the contrary, 100% (n = 18/18) of the isolates were sensitive to colistin sulfate. blaTEM was detected in 78% (n = 14/18) ampicillin-resistant isolates, whereas sul2 was found in 31% (n = 5/16) of the sulfamethoxazole-trimethoprim-resistant isolates.Conclusion:This study, first time in Bangladesh, highlights a significant proportion of environmental fecal samples from captive Bengal tigers at Safari parks harboring antibiotic resistant E. coli. Transmission of resistant E. coli from Bengal tigers to humans and the environment could pose a public health risk at Safari parks in Bangladesh.

Assessment of Microbial Populations in the Manufacture of Vacuum-Packaged Ready-to-Eat Roast Beef and in a Related Production Plant

Some microbiological criteria were monitored for 6 months in vacuum-packaged roast beef (15 production batches), raw beef (10 batches), and other meat products (12 batches) produced in an Italian small to medium-size enterprise. Fifty-five environmental swab samples also were analyzed. The main bacterial groups were identified by cultural methods according to International Organization for Standardization standards. Listeria monocytogenes was enumerated with the most-probable-number protocol, and species identification was confirmed with a specific PCR assay. Immediately after vacuum packaging, all ready-to-eat (RTE) products had low mean aerobic colony counts (<102 to 2.4 × 102 CFU g-1), anaerobic colony counts (1.6 to 6.5 × 101 CFU g-1), Enterobacteriaceae counts (1.1 to 1.4 × 101 CFU g-1), and Escherichia coli counts (generally below the detection limit). Nevertheless, the prevalence of L. monocytogenes in these samples was 3.7%. In roast beef samples, the aerobic and anaerobic colony counts reached unacceptable levels (>106 CFU g-1) after 14 days of refrigerated storage. Because the prevalence of L. monocytogenes increased to 13.3% during storage, a substantial reduction in the shelf life of these products is recommended. Surfaces without direct contact with food (floors and drains) had the highest mean counts for aerobic colonies (8.0 × 103 to 9.5 × 105 CFU/cm2), anaerobic colonies (2.9 × 103 to 3.2 × 104 CFU/cm2), Enterobacteriaceae (1.5 × 101 to 8.4 × 101 CFU/cm2), and E. coli (6.0 to 7.7 CFU/cm2). The levels of L. monocytogenes on direct food contact surfaces were below the detection limit, but more than 25% of floor samples were contaminated. These results reveal the persistence of L. monocytogenes in food processing environments, although at very low levels, posing a high risk of postcooking recontamination for RTE products. To improve hygienic conditions and reduce cross-contamination, an increase in operator awareness and a reassessment of surface sanitization protocols are needed.

Environmental transmission of Clostridioides difficile ribotype 027 at a long-term care facility; an outbreak investigation guided by whole genome sequencing.

This article describes a CDI outbreak in a long-term care (LTC) facility that used molecular typing techniques and whole-genome sequencing to identify widespread dissemination of the clonal strain in the environment which was successfully removed after terminal cleaning. This study was conducted in a long-term care facility in Texas. A recently hospitalized LTC patient was diagnosed with CDI followed shortly thereafter by 7 subsequent CDI cases. A stool specimen was obtained from each patient for culturing and typing. An environmental point-prevalence study of the facility was conducted before and after terminal cleaning of the facility to assess environmental contamination. Cultured isolates were typed using ribotyping, multilocus variant analysis, and whole-genome sequencing. Stool samples were available for 5 of 8 patients; of these specimens, 4 grew toxigenic C. difficile ribotype 027. Of 50 environmental swab samples collected throughout the facility prior to the facility-wide terminal cleaning, 19 (38%) grew toxigenic C. difficile (most commonly ribotype 027, 79%). The terminal cleaning was effective at reducing C. difficile spores in the environment and at eradicating the ribotype 027 strain (P<.001). Using multilocus variance analysis and whole-genome sequencing, clinical and environmental strains were highly related and, in some cases, were identical. Using molecular typing techniques, we demonstrated reduced environmental contamination with toxigenic C. difficile and the eradication of a ribotype 027 clone. These techniques may help direct infection control efforts and decrease the burden of CDI in the healthcare system.

Lesser housefly (Fannia canicularis) as possible mechanical vector for Aleutian mink disease virus

Flies are known vectors for a variety of infectious diseases in animals. In fur mink farming, one of the most severe diseases is Aleutian disease, which is caused by the Aleutian mink disease virus (AMDV). The presence of large fly populations is a frequent issue in mink farms; however, no studies assessing their role as AMDV carrier vectors have been conducted to-date. In order to determine the presence of AMDV in aerial flies from an infected mink farm, flies (n = 254) and environmental swab samples (n = 4) were collected from two farm barns. Fannia canicularis (L.) (Diptera: Muscidae) represented more than 99% of the fly population. One hundred and fifty specimens of this species were divided into pools of ten flies and analysed by qPCR, and positive samples were further sequenced. All fly pools and environmental samples tested positive for AMDV, and sequence analysis revealed identical genotypes in both types of samples. This is the first report of AMDV contamination in flies from mink farms, suggesting that F. canicularis may act as an AMDV vector. These results may be of interest for epidemiological studies and also for the improvement of control measures against this virus in mink farms.

Maintenance of Carbapenemase-Producing Enterobacteriaceae in a Farrow-to-Finish Swine Production System.

Carbapenemase-producing Enterobacteriaceae (CPE) threaten both agriculture and public health. While carbapenems are restricted in food-producing animals, other β-lactams, such as ceftiofur, are frequently applied in livestock. While the relationship is not fully elucidated, ceftiofur use may provide selective pressure that promotes carbapenem resistance. Recently reported in U.S. livestock, plasmid-mediated CPE are also present in livestock in Europe and Asia. We previously reported the rare carbapenemase gene, blaIMP-64, in the environment of a large farrow-to-finish swine operation. To better understand CPE in this swine production system, in 2016 we followed a cohort of 350+ pigs over 5 months from late sow gestation to the final finishing phase. We screened both environmental and fecal samples for CPE using our selective enrichment protocol, with resulting phenotypic CPE isolates further characterized. Of 55 environmental and 109 sow fecal samples collected from a farrowing barn on our initial visit, 35 (64%) environmental and 15 (14%) sow fecal samples yielded isolates of multiple Enterobacteriaceae species carrying the metallo-β-lactamase gene blaIMP-64 on an IncQ plasmid. The frequency of IMP-64-positive environmental (n = 32), sow fecal (n = 30), and piglet fecal swab (n = 120) samples was highest for all groups when the market pig cohort was between 1 and 10 days, with observed prevalence of 97%, 28%, and 18%, respectively. After weaning, blaIMP-64 was detected in a single environmental sample from a nursery pen, with no CPE recovered in the finishing phase. Used in U.S. swine production to treat and control disease, ceftiofur is administered to piglets on this farm at birth, with males receiving a second dose at castration (≈day 7). Once introduced into animal agriculture, the common use of ceftiofur may provide the selection pressure required for CPE dissemination throughout large, intensively managed food animal populations housed in animal-dense environments.

Laboratory-based characterization and traceability of an outbreak of necrotising enterocolitis

Objective: Laboratory-based characterization and traceability were performed on an outbreak of necrotising enterocolitis (NEC) happened in a maternal and child health care hospital in China. Methods: Thirty-seven samples were collected from 3 NEC cases, that the clinical manifestations was bloody stools. Clostridium spp. isolation and identification were carried out on stool, breast milk, milk-based infant powder and environmental swab samples collected during NEC outbreak from October to November in 2016. Meanwhile, twenty-four swabs samples from ward environmental, staffs' hand as well as articles for neonates daily use were also collected and tested for Clostridium spp. after disinfection following outbreak. Pulsed-field gel electrophoresis (PFGE) analysis was performed on all Clostridium strains obtained. Results: 46% (17/37) samples were positive for a presumptive Clostridium spp. during the outbreak of NEC. One type of Clostridium spp. isolates was cultured from 10 samples including the hands of medical staffs, some medical equipments in the ward and milk-based infant powder ingested by the case, it was identified as C.butyricum. Another type of Clostridium spp. isolates was cultured from 2 samples including breast milk and inner wall of breast milk fresh-keeping bag, it was identified as C.sporogens. Both of these two types isolates were cultured from 5 samples including inner wall of breast milk box, inner wall of refrigerator, the handle of case's incubator and the case's stool. PFGE analysis showed that all 15 strains of C. butyricum and 7 strains of C.sporogens isolated from the samples mentioned above produced indistinguishable pulsotypes respectively. No NEC cases were found after disinfection following the outbreak and all samples collected after outbreak were negative for Clostridium spp. Conclusion: The outbreak of NEC was highly related to C. butyricum contamination within the hospital.

Occurrence of Acanthamoeba genotypes in Central West Malaysian environments

Acanthamoeba species are ubiquitous free-living protozoa that can be found worldwide. Occasionally, it can become parasitic and the causative agent of acanthamoebic keratitis (AK) and Granulomatous Amoebic Encephalitis (GAE) in man. A total of 160 environmental samples and 225 naturally-infected animal corneal swabs were collected for Acanthamoeba cultivation. Acanthamoeba was found to be high in samples collected from environments (85%, 136/160) compared to infected animal corneas (24.89%, 56/225) by microscopic examination. Analysis of nucleotide sequence of 18S rRNA gene of all the 192 cultivable Acanthamoeba isolates revealed 4 genotypes (T3, T4. T5 and T15) with T4 as the most prevalent (69.27%, 133/192) followed by T5 (20.31%), T15 (9.90%) and T3 (0.52%). Genotype T4 was from the strain of A. castellanii U07401 (44.27%), A. castellanii U07409 (20.83%) and A. polyphagaAY026243 (4.17%), but interestingly, only A. castellanii U07401 was detected in naturally infected corneal samples. In environmental samples, T4 was commonly detected in all samples including dry soil, dust, wet debris, wet soil and water. Among the T4, A. castellanii (U07409) strains were detected high occurrence in dry (45%) followed by aquatic (32.50%) and moist (22.50%) samples but however A. castellanii (U07401) strains were dominant in dry samples of soil and dust (93.10%). Subsequently, genotype T5 of A. lenticulata (U94741) strains were dominant in samples collected from aquatic environments (58.97%). In summary, A. castellanii (U07401) strains were found dominant in both environmental and corneal swab samples. Therefore, these strains are possibly the most virulent and dry soil or dusts are the most possible source of Acanthamoeba infection in cats and dogs corneas.

P106: Functional assessment of the spine through an optoelectronic system in spinal disorders

Flies are known vectors for a variety of infectious diseases in animals. In fur mink farming, one of the most severe diseases is Aleutian disease, which is caused by the Aleutian mink disease virus (AMDV). The presence of large fly populations is a frequent issue in mink farms; however, no studies assessing their role as AMDV carrier vectors have been conducted to-date. In order to determine the presence of AMDV in aerial flies from an infected mink farm, flies (n = 254) and environmental swab samples (n = 4) were collected from two farm barns. Fannia canicularis (L.) (Diptera: Muscidae) represented more than 99% of the fly population. One hundred and fifty specimens of this species were divided into pools of ten flies and analysed by qPCR, and positive samples were further sequenced. All fly pools and environmental samples tested positive for AMDV, and sequence analysis revealed identical genotypes in both types of samples. This is the first report of AMDV contamination in flies from mink farms, suggesting that F. canicularis may act as an AMDV vector. These results may be of interest for epidemiological studies and also for the improvement of control measures against this virus in mink farms.