Rodent Damage Research Articles

Evidence of acrolein as an inflammatory biomarker in synovial fluid of dogs with osteoarthritis

Purpose: Endogenous acrolein is considered a toxic aldehyde that is a byproduct of tissue trauma. It has been shown to be present in diseases associated with brain and spinal cord and to exacerbate tissue inflammation and damage in humans and rodents. Anti-acrolein treatments have resulted in clinical improvements by reducing oxidative stress in damaged tissues. The first aim of this pilot study was to evaluate and compare presence of acrolein in the synovial fluid (SF) of dogs with osteoarthritis (OA) and Control joints.

A comparative study on assessing rodent damage intensity in rice crop based on two different methods

Rodent damage is commonly concentrated towards the center of rice fields. There are some approaches to assess the damage, two of them are the transect and the Malayan method. The transect technique is a well-known applicable practice employed among agricultural workers in Indonesia, while the Malayan method is generally performed in Malaysia. The objective of this study was to compare both methods in terms of determining the more representative technique for assessing rodent damage. The study was conducted in Karanggetas village, Bangodua subdistrict, Indramayu district, West Java (6°51’S, 108°29’E) in 2018. Two plots (0.35 ha and 0.56 ha) were selected as the study site which was planted with Inpari 32. Since the generative stage of the rice crop is the most preferable phase for rodents, therefore we solely observed the damage within this period. We recorded the damage intensity four times with weekly intervals by both methods in each plot. To confirm the rodent population and reproduction status, we installed a linear trap barrier system and dug some active burrows along the irrigation channel bank as their main habitat. The result showed that the damage intensity was significantly different between both methods. The damage intensity was higher when it was assessed by the transect method compared to the Malayan one. The result indicated that the transect method is a better technique representing the damage than the Malayan method. This due to the first method covered almost entirely the damaged spot. This finding suggested that the transect method is the representative technique for assessing rodent damage intensity.

The causes of holes and loss of physical integrity in long\u2010lasting insecticidal nets

BackgroundLong-lasting insecticidal nets (LLINs) are expected to last for at least 3 years, but whilst this may be achieved from an insecticidal perspective, physical protection is frequently compromised much earlier because of the rapid accumulation of holes during use. To understand why LLINs are so susceptible to loss of physical integrity, thousands of hole damage sites in LLINs retrieved from the field in Africa and Asia were forensically studied to identify the persistent underlying causes.MethodsA total of 525 LLINs consisting of six different brands from five different countries across Africa and Asia were collected from the field after 1 to 3 years in use. More than 42,000 individual sites of hole damage were analysed based on the morphology and size of each individual hole, aided by optical microscopy (OM) and scanning electron microscopy (SEM). The fracture morphology enabled positive identification of the underlying mechanisms of the damage.ResultsAcross all LLINs and geographical settings, mechanical damage is the primary cause of holes and loss of physical integrity in LLINs (63.14% by frequency and 81.52% by area). Snagging is the single most frequent mechanical damage mechanism, whilst the largest sized holes in LLINs result from seam failure and tearing. Abrasion and hole enlargement are also responsible for a progressive loss in the physical integrity of nets. Collectively, these five modes of mechanical damage can be expected to result from normal use of LLINs by households. Evidence of deliberate cutting, burn holes and rodent damage was observed to a lesser degree, which LLINs are not designed to withstand.ConclusionsLoss of physical integrity in LLINs is an inevitable consequence of using a vector control product that has an inherently low resistance to mechanical damage during normal use. To improve performance, new specifications based on laboratory textile testing is needed, to assess the resistance of LLIN products to the primary causes of mechanical damage when in use, which are snagging, tearing, abrasion and hole enlargement. Seam construction also needs to meet a revised minimum standard to reduce the risk of a rapid loss of physical integrity during use.

Rodent management modules against Bandicota bengalensis Gray & Hardwicke in Rice

Treatments efficacy assessed for rodent incidence and tiller damage revealed that all the treatments caused significant reduction of rat live burrows and rat tiller damage over control. Integration of rodent management techniques in Module-1 (trapping- bromadiolone poison baiting - burrow smoking) and Module-2 (Zinc Phosphide poison baiting-bromadiolone poison baiting-Aluminium Phosphide burrow application) found promising with significantly lowered rodent incidence and crop damage. % reduction in live burrows was 68.6 and 71.1 during 2017–18 and 61.8 and 65.8 during 2018–19 in Module-1 and 2, respectively. Tiller damage protection % was 65.9 and 68.9 in 2017–18 and 67.2 and 69.9 during 2018–19 for these treatments. Continuous application of rodenticides solo in M-5 (ALP) and M-4 (bromadiolone) also showed superior performance in containing the rodent damage and they are at par with the integrated treatments at certain crop stages. All the treatments recorded significant yield advantage over the control, but the benefit cost ratio were found relatively higher in the rodenticide treatments, highest (8:1) in the Module-2.

Hermetic Storage of Shelled Peanut Using the Purdue Improved Crop Storage Bags1

ABSTRACT Low oxygen or hermetic storage has been successfully used to store several commodities such as corn (Zea mays L.), cowpea (Vigna Savi), cocoa (Theobroma cocao), coffee (Coffea L.), and rice (Oryza sativa L.). However, previous research using hermetic storage for peanut or groundnut (Arachis hypogaea L.) had mixed results. Research was conducted to determine the effect on aflatoxin contamination, seed germination, and oil chemistry of shelled peanut hermetically stored in the Purdue Improved Crop Storage (PICS) bags for up to 12 months. A 2 × 4 factorial study included 1) normal and high oleic peanut, 2) two initial moisture contents by four storage treatments. The four storage treatments were 1) burlap bags as the control, 2) PICS bags, 3) PICS bags with air extracted by vacuum, and 4) PICS bags with sachets of chlorine dioxide (ClO2) dry fumigant added. There were three replications of each treatment combination. Peanut was stored in an area maintained at a temperature above 21C. The initial seed germination of the normal oleic and high oleic peanuts was 77 and 80%, respectively. Initial aflatoxin concentration in all peanut was less than 2 μg/kg. Bags were opened, sampled, and resealed at 60, 159, 249, and 301 d of storage. Approximately half of the 12 burlap bags suffered significant rodent damage, and all had significant infestation by Indian meal moth (Plodia interpunctella). Only 4 PICS bags had rodent damage with damage limited to the outer polypropylene bag. There were no live insects in the PICS bags. Seed germination decreased for all samples to an average of 6.3%. Peanut stored in the burlap bags had an average germination of 19.2% compared to 2.1% for peanut stored in PICS bags. The aflatoxin concentration in one of the burlap bags with normal oleic peanuts was 75 μg/kg, and one of the PICS bags with high oleic peanuts had an aflatoxin concentration of 12 μg/kg. The remaining samples had aflatoxin below the detectable limit of 2 μg/kg.

Damage by Rodent in Rice-Green gram cropping system in Brahmaputra Valley Zone

The results indicated that live burrow count (LBC), trapping index (TI) and rodent damage (%) recorded at different crop growth stages increased with the advancement of the crop growth. Maximum LBC (44.46), trap index (7.11) and cut tillers (6.41%) was recorded at harvesting stage of the rice followed by ripening stage with a mean LBC of 41.06, trap index of 6.88 and 6.41% cut tillers. Field rodents started damage from tillering stage of the rice crop. Rodents establishment in the rice field was completed by the panicle initiation stage. Pea crop grown after rice i.e. from November to February, the highest incidence was recorded at harvesting stage with a mean LBC of 36.11, trap index of 4.81 and 4.44% damage. Green gram crop grown after rice faced less rodent infestation in rice-green gram sequence.

WinDAM C: Analysis Tool for Predicting Breach Erosion Processes of Embankment Dams Due to Overtopping or Internal Erosion

HighlightsThe computational models comprising the current version of WinDAM, called WinDAM C, are summarized.WinDAM C estimates the response of an earthen embankment subjected to overtopping or internal erosion.WinDAM C is a model that quantifies erosion/breach processes observed in physical embankment failure tests.Understanding the current technology and limitations provides a basis for further model development.Abstract. Internal erosion and overtopping erosion of earthen embankments are the leading causes for earthen embankment failures. Challenges like reservoir sedimentation, structural deterioration, rodent damage or tree root growth, and changing hazard classification from low to significant or high have arisen with aging dams. To address these challenges, new technology and tools for predicting the performance of homogeneous, cohesive earthen embankments during overtopping or internal erosion are needed. Windows Dam Analysis Modules (WinDAM) is a modular software application developed through collaborative efforts of the United States Department of Agriculture (USDA) Agricultural Research Service (ARS), the USDA-Natural Resources Conservation Service (NRCS), and Kansas State University (KSU) in response to this need. WinDAM uses a simple storage routing model to simulate flow through a reservoir and incorporates algorithms for predicting the progression of erosion resulting from embankment overtopping or flow through an internal discontinuity in the embankment. These algorithms are based on existing literature and data and observations from physical model experiments of homogeneous, cohesive embankments conducted by scientists at the USDA-ARS Hydraulic Engineering Research Unit in Stillwater, Oklahoma. The resulting computational model is a simplified representation of the observed process of progressive erosion that may lead to embankment breach. This paper reviews the components of the erosion/breach process and the way in which these components are quantified and integrated into the current WinDAM software, WinDAM C. The scope of application of the software, limitations, and computational assumptions are also discussed. Keywords: Breach, Dams, Erodibility, Erosion Process, Failure, Internal erosion, Model, Overtopping, Piping.

Evaluation of methylanthranilate based repellent formulations and mode of delivery to prevent rodent damage under storage conditions

Evaluation of methylanthranilate based repellent formulations and mode of delivery to prevent rodent damage under storage conditions

Co-culture model of Caco-2/HT29-MTX cells: A promising tool for investigation of phycotoxins toxicity on the intestinal barrier

Most lipophilic phycotoxins have been involved in human intoxications but some of these toxins have never been proven to induce human gastro-intestinal symptoms, although intestinal damage in rodents has been documented. For investigating the in vitro toxicological profile of lipophilic phycotoxins on intestine, the epithelial Caco-2 cell line has been the most commonly used model. Nevertheless, considering the complexity of the intestinal epithelium, in vitro co-cultures integrating enterocyte-like and mucus-secreting cell types are expected to provide more relevant data. In this study, the toxic effects (viability, inflammation, cellular monolayer integrity, modulation of cell type proportion and production of mucus) of four lipophilic phycotoxins (PTX2, YTX, AZA1 and OA) were evaluated in Caco-2/HT29-MTX co-cultured cells. The four toxins induced a reduction of viability from 20% to 50% and affected the monolayer integrity. Our results showed that the HT29-MTX cells population were more sensitive to OA and PTX2 than Caco-2 cells. Among the four phycotoxins, OA induced inflammation (28-fold increase of IL-8 release) and also a slight increase of both mucus production (up-regulation of mucins mRNA expression) and mucus secretion (mucus area and density). For PTX2 we observed an increase of IL-8 release but weaker than OA. Intestinal cell models integrating several cell types can contribute to improve hazard characterization and to describe more accurately the modes of action of phycotoxins.

Increased Hepatic ACE2 Expression in NAFL and Diabetes-A Risk for COVID-19 Patients?

The current pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced disease (coronavirus disease 2019 [COVID-19]) is a major global threat. Although most infected patients have a mild course, a relevant proportion of approximately 20% develop a severe and often lethal condition. Recent findings demonstrate that COVID-19 is a multiorgan disease. In addition to the characteristic pneumonia, it affects heart, kidney, pancreas, the coagulation system, and liver. Major risk factors for severe COVID-19 with multiorgan complications include male sex, older age (>65 years), cardiovascular and chronic lung disease, and especially diabetes (1,2). However, it is still unclear why these conditions predispose to a severe course of COVID-19. To enter the target cell, SARS-CoV-2 requires the binding of its spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor (3). The entry is additionally facilitated by subsequent priming and cleavage of the spike protein through proteases such as transmembrane serine protease 2 (TPMRSS2) and furin (3). While the ACE2 receptor is mainly expressed in heart, lungs, endothelial cells, kidney, and the gastrointestinal tract, expression has also been detected in cholangiocytes and in lower amounts in hepatocytes (4). Of note, hepatic ACE2 expression was found to be increased upon chronic liver damage in rodents as well as in humans. Nonalcoholic fatty liver (NAFL) is the most prevalent liver disorder in people with type 2 diabetes and is present in …

Peoples’ perception of rodents as pest and their control in Ibadan, South-western Nigeria: A case study of University of Ibadan, Ibadan, Oyo State

The prolific rate of rodents in the University of Ibadan is becoming alarming and thus there is need to investigate their perception of rodents as pests by the people residing within the University premises. The study design employed was descriptive and data was collected using self-structured research questionnaires. A total of One hundred and twenty (120) questionnaires were administered and retrieved from the respondents. The results of the findings showed that majority of the respondents 96(80%) were aware of the rodents’ presence on campus. Ninety eight (81.7%) of the respondents had knowledge of rodents as pests while 50 (41.7%) respondents perceived food materials as what are mostly damaged by rodents. Fifty five (45.9%) respondents indicated that the extent of rodents damage to their belongings was serious while 45 (38.3%) reported it to be insignificant. Use of rodenticides was the method mostly adopted by 66 (55%) respondents to reduce rodent damage followed by setting of traps by 37 (30.8%). There was no significant difference between the methods employed to reduce rodent damage (p˃0.05) by the respondents. It can be concluded that rodents are recognized as pests that cause damage to human belongings in the study area and methods of control perceived to be mostly used to reduce rodent damage are the use of rodenticides and setting of traps.

Potential of a synthetic predatory cue in reducing damage caused by Rattus rattus

The aim of the present study was to assess the potential of synthetic predatory cue containing sulphurous odours as an area repellent to reduce rodent damage. Groups of mature Rattus rattus of both sexes were exposed to 0.5%, 1% and 2% concentrations of 2,4,5-trimethylthiazole (TMTZ), a synthetic predatory cue, applied through cotton swab under laboratory and simulated indoor store conditions. Laboratory experiment revealed lower food consumption by rats from the treated side of chamber compared to the untreated side at all three concentrations of TMTZ exposed once in a week with up to 61.70% and 67.90% repellency in male and female rats, respectively. Daily exposure of TMTZ resulted in up to 84.90% repellency in males and 76.70% in females. Under simulated store conditions, 1% TMTZ exposed once completely prevented damage to treated bags containing wheat grains for up to 12 days in male and 14 days in female rats indicating sex-specific differences in response towards TMTZ. The present study suggests the potential of TMTZ in reducing damage caused by R. rattus under indoor storage conditions.

The hemodynamic and metabolic effects of spironolactone treatment in acute kidney injury assessed by hyperpolarized MRI.

Renal ischemia-reperfusion injury (IRI) is one of the most common types of acute kidney injury. Spironolactone has shown promising kidney protective effects in renal IRI in rats. We investigated the hemodynamic and metabolic effects of spironolactone (100 mg/kg) administered immediately after 40 min unilateral kidney ischemia in rats. Hyperpolarized MRI using co-polarized [1-13 C]pyruvate and [13 C,15 N2 ]urea as well as 1 H dynamic contrast-enhanced (DCE) MRI was performed 24 h after induction of ischemia. We found a significant decrease in renal blood flow (RBF) in the ischemic kidney compared with the contralateral one measured using DCE and [13 C,15 N2 ]urea. The RBF measured using [1-13 C]pyruvate and [13 C,15 N2 ]urea was significantly altered by spironolactone. The RBFs in the ischemic kidney compared with the contralateral kidney were decreased similarly as measured using both [13 C,15 N2 ]urea and [1-13 C]pyruvate in the spironolactone-treated group. Spironolactone treatment increased the perfusion-corrected pyruvate metabolism by 54% in both the ischemic and contralateral kidney. Furthermore, we showed a correlation between vascular permeability using a histological Evans blue analysis and the ratio of the volumes of distribution (VoDs), ie VoD-[13 C,15 N2 ]urea/VoD-[1-13 C]pyruvate. This suggests that [13 C,15 N2 ]urea/[1-13 C]pyruvate VoD ratio may be a novel indicator of renal vascular permeability associated with renal damage in rodents.

Maternal exposure to Di-(2-ethylhexyl) phthalate (DEHP) activates the PI3K/Akt/mTOR signaling pathway in F1 and F2 generation adult mouse testis

Di-(2-ethylhexyl) phthalate (diethylhexyl phthalate, DEHP) can cause male reproductive damage in rodents and human. Moreover, DEHP is known to promote transgenerational inheritance of adult-onset disease in subsequent generations after maternal exposure during fetal gonadal development. The PI3K/Akt/mTOR signaling pathway has been implicated in germ cell survival following testicular damage. In this study, a F0 gestation DEHP exposure and transgenerational inheritance testis injury model was established to study the testis injury phenotype and the expression and activation of members of PI3K/Akt/mTOR signaling pathway in the testis of F1–F3 generation mice. We found that the bodyweight and the anogenital distance (AGD) are reduced only in F1 mice, the sperm motility and deformity decreased in F1–F3 mice, and the testicular histomorphology damagedin F1–F3 mice; however the sperm motility and deformity rates are increased and the histomorphological injury is repaired during the transgenerational process. We also found the activation of PI3K/Akt/mTOR signaling pathway is enhanced in F1 and F2, and the number of apoptotic cells is decreased in F3 generation mice compared to the control group. These results suggest that the PI3K/Akt/mTOR signaling pathway may be activated to promote the proliferation and differentiation and protect testicular cells from apoptosis in the F1 and F2 generation mice after direct exposure to DEHP.

Farmers’ perspectives of rodent damage and rodent management in smallholder maize cropping systems of Southern Ethiopia

A survey was conducted in Chano area, Southern Ethiopia, to investigate farmers' viewpoints with regard to rodent pest problems. Farmers (n = 384) were interviewed using semi-structured questionnaire between October 2018 and January 2019. Pests were implied (51%) as the major constraints of cereal crop production followed by shifting to cash crops (20.6%), waterlogged farmlands (15.6%), infertile soils (8.6%) and insufficient rains (4.2%). Farmers experienced rodent outbreaks (83%) and identified maize (98%) as a crop most susceptible to rodent damage. Farmer suffered 23.5% average annual maize loss due to rodents. Being male (OR = 2.82, P < 0.05) and years spent in farming (OR = 1.13, P < 0.001) increased the likelihood of farmers' experience with rodent outbreaks. Seedling stage of maize was identified as the stage most susceptible to rodent damage (64.8%), followed by harvesting (19.3%) and maturity (15.9%) stages. When adjusted for other factors, a year increase in farming as an occupation decreased farmers' estimate of annual maize yield loss due to rodent damage by a coefficient of 0.04 (P < 0.05). An individual's experience (86.5%) was the major factor in deciding the type of rodent pest management. Application of rodenticides was the most frequently used (76%) rodent management method. We recommend awareness creation and extension support to the farmer community to reduce the reliance on toxic rodenticides and shift to community-based integrated rodent management approaches that would reduce the unacceptable damage levels.

Rodent damage to rice crops is not affected by the water-saving technique, alternate wetting and drying

Rice farmers in Southeast Asia are hesitant to adopt the water-saving technology, alternate wetting and drying (AWD), for fear the practice will lead to increased rodent pest activity, consequently exacerbating yield loss. We examined the effects of AWD on the population dynamics, habitat use and damage levels inflicted on rice crops by the most important rodent pest of rice in Indonesia and the Philippines, Rattus argentiventer and R. tanezumi, respectively. Rice crop damage levels were not affected by the water management scheme employed. Rodent activity in rice fields was not influenced by water level. Both species tended to use the rice paddies over bunds regardless of water level, indicating that something other than water affects their habitat use, and we argue it is likely that the perceived risk of predation is the primary factor driving habitat use. Activity levels and damage inflicted by rodent pests on rice were not correlated. AWD had no effect on breeding and population dynamics of these species. Breeding of R. argentiventer is tied to the growth stages of rice, while available resource dictates breeding by R. tanezumi. Our findings clearly indicate that rice farmers in both Indonesia and the Philippines have no cause to reject AWD based on concerns that AWD would exacerbate crop losses by rodents. Given AWD is being promoted as a climate-smart technology for rice production in Asia and Africa, we strongly recommend its adoption without concerns that it would aggravate rodent pest impacts in lowland irrigated rice cropping systems.

Complex biotic interactions mediated by shrubs: Revisiting the stress‐gradient hypothesis and consequences for tree seedling survival

Abstract Using nurse shrubs to improve tree seedling establishment in stressed environments is a common practice in forestry. Recent refinements of the stress‐gradient hypothesis suggest that positive nurse effects occur under intermediate stress and decline in the harshest conditions. Additionally, indirect facilitation (e.g. protection from herbivory) is expected in low‐stressed/productive systems according to the initial stress‐gradient hypothesis. However, there have been fewer investigations into the use of nurse shrubs to decrease herbivore impacts in stressed systems compared with the role of nurses in stress alleviation. This raises the need to clarify conditions in which the use of nurse shrubs would be most appropriate. We conducted a field experiment in the sand dune forest of southwest France characterized by severe summer water shortages and the presence of different types of wild herbivores. In 2015 and 2016, Pinus pinaster seedlings were planted under shrubs Arbutus unedo or in shrub‐removed locations, in fenced/unfenced areas. Survival, cause of mortality and water stress were monitored for 1 year after plantation. Summer drought was the main cause of mortality. Water stress increased in both years as summer progressed. We found direct facilitation only in July 2016 at intermediate water stress, due to a decrease in vapour pressure deficit under shrubs. These positive effects declined in late summer when stress was at a maximum. Rodent damage occurred under shrubs in spring whereas ungulate browsing was observed in open areas in autumn/winter. Overall seedling survival was equivalent under or outside shrubs during the first year, but was better under shrubs in the second one. Synthesis and applications. Our results partially validate the refinement of the stress‐gradient hypothesis, with a decline of positive interactions in the most water‐stressed conditions. This draws attention to the difficulty of using shrubs as nurses to improve tree regeneration in the most xeric systems. In addition, we show that indirect associational effects, both positive and negative, could be as important as abiotic stress alleviation in a stressful ecosystem, and using shrubs to facilitate seedling survival could be efficient depending on the type of herbivore involved. This highlights the fact that considering plant–plant interactions can help in the design of management options, providing that up‐to‐date ecological theories are considered and that the different biotic and abiotic constraints are accurately evaluated.

Destructive Effect of Intravitreal Heat Shock Protein 27 Application on Retinal Ganglion Cells and Neurofilament.

Heat shock protein 27 (HSP27) is commonly involved in cellular stress. Increased levels of HSP27 as well as autoantibodies against this protein were previously detected in glaucoma patients. Moreover, systemic immunization with HSP27 induced glaucoma-like damage in rodents. Now, for the first time, the direct effects of an intravitreal HSP27 application were investigated. For this reason, HSP27 or phosphate buffered saline (PBS, controls) was applied intravitreally in rats (n = 12/group). The intraocular pressure (IOP) as well as the electroretinogram recordings were comparable in HSP27 and control eyes 21 days after the injection. However, significantly fewer retinal ganglion cells (RGCs) and amacrine cells were observed in the HSP27 group via immunohistochemistry and western blot analysis. The number of bipolar cells, on the other hand, was similar in both groups. Interestingly, a stronger neurofilament degeneration was observed in HSP27 optic nerves, while no differences were noted regarding the myelination state. In summary, intravitreal HSP27 injection led to an IOP-independent glaucoma-like damage. A degeneration of RGCs as well as their axons and amacrine cells was noted. This suggests that high levels of extracellular HSP27 could have a direct damaging effect on RGCs.

Characteristics of Bandicota bengalensis burrows during different growth stages of wheat crop in Punjab

Burrowing is an activity used by rodents for resting, sleeping and food hoarding purposes and is affected by different abiotic and biotic factors. In the present study, an attempt has been made to describe the burrow structure of Bandicota bengalensis in relation to different crop stages of wheat crop. We observe that as the growth stages of wheat crop change from tillering to lean period, there is change in pattern of burrow structure by rodents. The length of burrow was maximum (200.80±2.84cm) during tillering stage and minimum (172.40±2.97cm) during lean period, whereas the depth of burrow was minimum (52.50 ±1.65cm) during tillering and maximum (68.90±2.83cm) in lean period to keep the environment of burrow optimum when mean soil moisture (%) and soil temperature recorded were 25.62%, 14.72°C and 14.88%, 25.84°C, respectively. The mean number of open ends, blind ends, number of nest chambers and number of burrow branches were highest during dough stage and lowest during lean period. Present study will help in development of policies that include strategies for rodent pest management i.e. for placing poison baits in burrows so that the rodent damage to crops may be reduced to a minimum level and farm income may be increased.

Microbiological Contamination of Strawberries from U-Pick Farms in Guangzhou, China.

This study quantified the association of rodent fruit damage and the microbiological quality of irrigation water on the risk of microbiological contamination of strawberries collected from 18 U-pick farms across five different districts in the Guangzhou metropolitan region of southern China. Fifty-four composite strawberries samples, with or without evidence of rodent or avian foraging damage (i.e., bitten), along with 16 irrigation water samples, were collected during the spring of 2014 and winter of 2015 from our cohort of 18 farms. Composite strawberry samples and irrigation water were analyzed for total coliforms, E. coli, Salmonella, E. coli O157, Giardia, and Cryptosporidium. Total coliforms and E. coli were detected in 100% and ~90% of irrigation water samples, respectively. In contrast, Cryptosporidium was detected in only two water samples, while Salmonella, E. coli O157, and Giardia were not detected in any water samples. Strawberries with signs of being bitten by wildlife had significantly higher concentrations of total coliforms and E. coli, compared to strawberries with no physical evidence of rodent damage (p < 0.001). Similarly, Cryptosporidium was detected in 7/18 (39%) of bitten, 4/18 (22%) of edge, and 5/18 (28%) of central strawberry samples, respectively. Concentration of E. coli on strawberries (p < 0.001), air temperature (p = 0.025), and presence of Cryptosporidium in irrigation water (p < 0.001) were all associated with the risk of Cryptosporidium contamination on strawberries. Salmonella and Giardia were detected in <4% strawberry samples and E. coli O157 was not detected in any samples. These results indicate the potential food safety and public health risks of consuming unwashed strawberries from U-pick farms, and the need for improved rodent biosecurity of U-pick strawberry fields and enhanced microbiological quality of irrigation water used at these facilities.