Family poverty over the early life course and adult experiences of intimate partner violence: a cohort study.

OBJECTIVES: This study aimed to determine whether family poverty over the early childhood, adolescent, and adult periods of the life course independently predicts experiences of intimate partner violence (IPV) in adulthood. STUDY DESIGN: This was a birth cohort study in Brisbane, Australia, with pregnant women recruited at their first booking-in visit and their children, followed up to 30 and 40 years of age. METHODS: Family income was obtained from the mother when the child was 6 months, 5 and 14 years of age. Offspring reported their own family income at 21, 30, and 40 years of age. The offspring completed the Composite Abuse Scale at 30 and 40 years. Adjusted logistic regression models are used to predict experiences of IPV at 30 (n = 2157) and 40 (n = 1438) years. RESULTS: The findings at 30 and 40 years of age are consistent. Only poverty experienced concurrently with the assessment of IPV is strongly associated. At the 40-year follow-up, family poverty predicts higher ratios of all four forms of IPV; severe combined abuse (odds ratio [OR] = 2.24, 95% confidence interval [CI] = 1.24, 4.05), physical abuse (OR = 3.37, 95% CI = 1.95, 5.82), emotional abuse (OR = 2.09, 95% CI = 2.58, 8.57) and harassment (OR = 4.70, 95% CI = 2.58, 8.57). CONCLUSION: Concurrent family poverty is strongly and consistently associated with patterns of IPV. These associations are for cross-sectionally collected data with the prospectively collected data not replicating these findings. Although it is not possible to identify a specific causal pathway, the findings suggest that the immediate consequences of poverty are strongly associated with IPV. Programmes that address poverty reduction provide the best prospect for reducing societal levels of IPV.

Investigating the role of hallucinatory experiences in the transition from suicidal thoughts to attempts.

OBJECTIVE: Psychotic experiences, including auditory hallucinatory experiences (HEs), are strongly associated with both suicidal thoughts and behaviour. This study examined their role in the ideation-to-attempt transition in adolescents, including their direct and indirect effect via potential mediators. METHOD: Participants were from an Australian prospective longitudinal cohort of 1669 adolescents (12-17 years); of which a subsample endorsing baseline suicidal ideation (n = 216) was the focus of most analyses. Suicidal thoughts and behaviours were measured using the Self-Harm Behaviour Questionnaire. The Diagnostic Interview Schedule for Children was used to assess auditory HEs. Potential mediators of interest were psychological distress and Interpersonal Theory of Suicide (IPTS) constructs. RESULTS: Among adolescents reporting suicidal ideation at baseline (n = 216), 6.5% had attempted suicide during follow-up. The size of auditory HEs' univariate effect suggests a possible strong relationship with increased risk of incident suicide attempts (OR = 2.40; 95%CI = 0.76-7.56); however, there was inadequate statistical power to produce a precise estimate. When HEs were accompanied by distress there was a nine-fold increased risk of acting on suicidal thoughts. Distress was independently associated with risk of attempt transition (OR = 4.09), whereas IPTS constructs were poor explanatory variables in most models. CONCLUSION: Adolescents with psychological distress and auditory HEs are at high risk of incident suicide attempts. Further investigations on the role of negative/distressing content of hallucinations in the ideation-to-attempt transition are warranted.

Why are psychotic experiences associated with self-injurious thoughts and behaviours? A systematic review and critical appraisal of potential confounding and mediating factors.

Psychotic experiences (PEs), including hallucination- and delusion-like experiences, are robustly associated with self-injurious thoughts and behaviours (SITB) in the general population. However, it remains unclear as to why there is an association. The purpose of this systematic review was to elucidate the role of other factors that influence the association between PEs and SITB and, in doing so, highlight potential mechanisms underlying the relationship. A search of electronic international databases was undertaken, including PubMed, PsycINFO and EMBASE, and eligible studies were grouped according to seven confounder categories: sociodemographics, mental disorders, alcohol and substance use, environmental, psychological, intervention and family history/genetic factors. The systematic search strategy identified 41 publications reporting on 1 39 427 participants from 16 different countries. In the majority of studies, where adjustment for other variables occurred, the association between PEs and SITB persisted, suggesting PEs have an independent role. Common mental disorders, psychological distress and negative environmental exposures explained a substantial amount of the variance and therefore need to be considered as potential underlying mechanisms. There was high variability in the variables adjusted for in these studies, and so the question still remains as to whether the association between PEs and self-harm/suicidality can be attributed (fully or in part) to confounding and mediating factors or directly causal mechanisms. Regardless of causality, the now extensive literature reporting an association between these two clinical phenomena supports the broad usefulness of PEs as an indicator of risk for SITB.

The association between adolescent psychopathology and subsequent physical activity in young adulthood: a 21-year birth cohort study.

BACKGROUND: The beneficial effects of physical activity (PA) for both physical and mental wellbeing are well established. Given that adolescence presents a critical developmental period during which life-long patterns of PA become established, the exploration of the longitudinal impact of adolescent psychopathology on adult PA status is of interest. METHODS: We analysed prospective data from 3663 young adults who participated in the Mater-University of Queensland Study of Pregnancy. Psychopathology was measured using the Youth Self-Report (YSR) at age 14. Participants' engagement in three types of PA (vigorous exercise, moderate exercise and walking) at age 21 were dichotomised into either 'none' or 'any'. For our main analysis, we examined the association between the YSR score and subsequent PA engagement using logistic regression. We also conducted sensitivity analyses of longitudinal associations between the YSR internalising and externalising symptoms score at age 14 and PA engagement at age 21. RESULTS: We found no longitudinal association between the total YSR score at age 14 and PA engagement at age 21. In addition, there was no longitudinal association between the YSR internalising or externalising symptoms and PA engagement. CONCLUSION: Our findings suggest that there is no longitudinal association between adolescent psychopathology and PA in young adulthood.

Smokin' hot: adolescent smoking and the risk of psychosis.

OBJECTIVE: Daily smoking has been associated with a greater risk of psychosis. However, we are still lacking studies to adjust for baseline psychotic experiences and other substance use. We examined associations between daily smoking and psychosis risk in a 15-year follow-up while accounting for these covariates in a prospective sample (N = 6081) from the Northern Finland Birth Cohort 1986. METHODS: Self-report questionnaires on psychotic experiences (PROD-screen), tobacco smoking and other substance use were completed when the cohort members were 15-16 years old. Tobacco smoking was categorized into three groups (non-smokers, 1-9 cigarettes and ≥10 cigarettes/day). Psychosis diagnoses were obtained from national registers until the age of 30 years. RESULTS: Subjects in heaviest smoking category were at increased risk of subsequent psychosis (unadjusted HR = 3.15; 95% CI 1.94-5.13). When adjusted for baseline psychotic experiences the association persisted (HR = 2.87; 1.76-4.68) and remained significant even after adjustments for multiple known risk factors such as cannabis use, frequent alcohol use, other illicit substance use, parental substance abuse, and psychosis. Furthermore, number of smoked cigarettes increased psychosis risk in a dose-response manner (adjusted OR = 1.05; 1.01-1.08). CONCLUSION: Heavy tobacco smoking in adolescence was associated with a greater risk for psychosis even after adjustment for confounders.

Diversity of knockdown resistance alleles in a single house fly population facilitates adaptation to pyrethroid insecticides.

Insecticide use exerts a tremendous selection force on house fly populations, but the frequencies of the initial resistance mutations may not reach high levels if they have a significant fitness cost in the absence of insecticides. However, with the continued use of the same (or similar) insecticides, it is expected that new mutations (conferring equal or greater resistance, but less of a fitness cost) will evolve. Pyrethroid insecticides target the insect voltage sensitive sodium channel (VSSC) and have been widely used for control of house flies at animal production facilities for more than three decades. There are three Vssc mutations known that cause resistance to pyrethroids in house flies: knockdown resistance (kdr, L1014F), kdr-his (L1014H) and super-kdr (M918T + L1014F). Whether or not there are any new mutations in house fly populations has not been examined for decades. We collected house flies from a dairy in Kansas (USA) and selected this population for three generations. We discovered multiple new Vssc alleles, including two that give very high levels of resistance to most pyrethroids. The importance of these findings to understanding the evolution of insecticide resistance, designing appropriate resistance monitoring and management schemes, and the future of pyrethroids for house fly control are discussed.

Overcoming super-knock down resistance (super-kdr) mediated resistance: multi-halogenated benzyl pyrethroids are more toxic to super-kdr than kdr house flies.

Target site insensitivity because of mutations in the voltage-sensitive sodium channel gene (Vssc) is a major mechanism of resistance to pyrethroid insecticides in the house fly, Musca domestica. There are three known Vssc alleles that confer resistance to pyrethroids in the house fly: knock down resistance (kdr; L1014F), super-kdr (M918T + L1014F) and kdr-his (L1014H), but there has been no side-by-side comparison of the resistance levels that they confer. We compared the levels of resistance conferred by the three Vssc alleles in congenic strains to 19 structurally diverse pyrethroids, and compared the full-length Vssc cDNA sequences from each strain. Generally, the levels of resistance conferred were kdr-his < kdr < super-kdr. However, there was significant variation in this pattern, especially for super-kdr, for which both high and low resistance ratios were observed for several pyrethroids. We also examined the levels of resistance in heterozygotes. Resistance in each of the hybrids was generally inherited as an incompletely recessive trait, except for the kdr-his/kdr hybrids, which showed incompletely to completely dominant resistance (ie had resistance levels comparable to kdr homozygotes). The importance of these results to understanding the frequencies of these resistance alleles in natural populations, the evolution of insecticide resistance and resistance management strategies are discussed.

Emotional and behavioral problems in adolescents and young adults with food allergy.

BACKGROUND: Adolescents with food allergy have poorer psychosocial outcomes compared with their nonallergic counterparts; however, few studies have prospectively examined the mental health of adolescents and young adults in this vulnerable population. Our objectives were to estimate the prevalence of emotional and behavioral problems in an epidemiological sample of adolescents and young adults with food allergy; determine whether food allergy is associated with adolescent and maternal reports of such problems; and examine the patterns of change in emotional and behavioral problems from adolescence to young adulthood among individuals with and without food allergy. METHODS: Data came from 1303 participants at 14 and 21 years of age in the Mater University Study of Pregnancy. Emotional and behavioral problems were measured using self- and maternal-reported symptoms of depression, anxiety, attention/deficit hyperactivity disorder (ADHD), oppositional defiant disorder, and conduct disorder. RESULTS: Maternal, but not self-reports suggested that emotional and behavioral problems were higher among adolescents with food allergy. Food allergy was associated with increased odds of elevated levels of maternal-reported symptoms of depression [OR = 4.50 (1.83, 11.07)], anxiety [OR = 2.68 (1.12, 6.44)], and ADHD [OR = 3.14 (1.07, 9.19)] in adolescence. Food allergy was also associated with depressive symptoms that persisted from adolescence to young adulthood [OR = 2.05 (1.04, 4.03)]. CONCLUSIONS: Emotional and behavioral problems, particularly symptoms of depression, anxiety, and ADHD, are common among adolescents with food allergy in the general population and, in the case of elevated levels of depressive symptoms, persist into young adulthood. Healthcare professionals should seek adolescent and parental perspectives when assessing emotional and behavioral problems and monitor mental health during the transition to adulthood.

Correlates of physical activity in people living with psychotic illness.

OBJECTIVE: In the light of the high prevalence of physical comorbidities in people with psychotic illness, there is a need to explore modifiable risk factors that may contribute to this disease burden. The benefits of physical activity to both physical and mental health have been well established. We aimed to examine the prevalence and correlates of physical activity in a national sample of adults living with psychotic illness. METHODS: Physical activity was assessed in 1801 people using the International Physical Activity Questionnaire. Participants were dichotomised into low and moderate-high physical activity groups and associations between physical activity and a range of sociodemographic, clinical and physical comorbidity variables were examined using logistic regression. RESULTS: More than half the participants were categorised in the moderate-high physical activity group with nearly half of the sample engaged in physical activity every day. There were significant associations between low physical activity and older age, unemployment, educational non-participation, antipsychotic medication use, social dysfunction, self-reported loneliness and obesity. However, there was no significant association between physical activity and sex, psychosis type, illness duration, physical comorbidity or negative symptoms. CONCLUSION: The findings from this study may inform future interventions designed to increase physical activity in people with psychotic illness.

Autoimmune encephalitis.

Over the past decade, the clinical spectrum of autoimmune encephalitis has expanded with the emergence of several new clinicopathological entities. In particular, autoimmune encephalitis has recently been described in association with antibodies to surface receptors and ion channels on neurological tissues. Greater clinician awareness has resulted in autoimmune encephalitis being increasingly recognised in patients with unexplained neurological and psychiatric symptoms and signs. The clinical spectrum of presentations, as well as our understanding of disease mechanisms and treatment regimens, is rapidly developing. An understanding of these conditions is important to all subspecialties of Internal Medicine, including neurology and clinical immunology, psychiatry, intensive care and rehabilitation medicine. This review provides a contemporary overview of the aetiology, investigations and treatment of the most recently described autoimmune encephalitides.

Psychotic experiences and psychological distress predict contemporaneous and future non-suicidal self-injury and suicide attempts in a sample of Australian school-based adolescents.

BACKGROUND: Recent cross-sectional studies have shown psychotic experiences (PEs) are associated with suicidal ideation and behaviours. We aimed to examine associations between psychotic experiences (including persistent PE), and contemporaneous and incident non-suicidal self-injury (NSSI) and suicide attempts. METHOD: Participants were from an Australian longitudinal cohort of 1896 adolescents (12-17 years). NSSI and suicide attempts were measured using the Self-Harm Behaviour Questionnaire. Items from the Diagnostic Interview Schedule for Children were used to assess psychotic experiences, and the General Health Questionnaire-12 measured psychological distress. RESULTS: Adolescents both psychologically distressed and endorsing psychotic experiences had increased odds of contemporaneous and incident NSSI and attempted suicide. Psychotic experiences alone did not predict future risk. Persistent psychotic experiences were associated with increased risk of NSSI and suicide attempts. CONCLUSIONS: Psychological distress with accompanying psychotic experiences and persistent psychotic experiences are important predictors of NSSI and suicide attempts. Screening these phenotypes in adolescents will assist in discerning those adolescents most at risk, providing opportunities for targeted suicide prevention strategies.

The epidemiology and global burden of autism spectrum disorders.

BACKGROUND: Autism spectrum disorders (ASDs) are persistent disabling neurodevelopmental disorders clinically evident from early childhood. For the first time, the burden of ASDs has been estimated for the Global Burden of Disease Study 2010 (GBD 2010). The aims of this study were to develop global and regional prevalence models and estimate the global burden of disease of ASDs. METHOD: A systematic review was conducted for epidemiological data (prevalence, incidence, remission and mortality risk) of autistic disorder and other ASDs. Data were pooled using a Bayesian meta-regression approach while adjusting for between-study variance to derive prevalence models. Burden was calculated in terms of years lived with disability (YLDs) and disability-adjusted life-years (DALYs), which are reported here by world region for 1990 and 2010. RESULTS: In 2010 there were an estimated 52 million cases of ASDs, equating to a prevalence of 7.6 per 1000 or one in 132 persons. After accounting for methodological variations, there was no clear evidence of a change in prevalence for autistic disorder or other ASDs between 1990 and 2010. Worldwide, there was little regional variation in the prevalence of ASDs. Globally, autistic disorders accounted for more than 58 DALYs per 100 000 population and other ASDs accounted for 53 DALYs per 100 000. CONCLUSIONS: ASDs account for substantial health loss across the lifespan. Understanding the burden of ASDs is essential for effective policy making. An accurate epidemiological description of ASDs is needed to inform public health policy and to plan for education, housing and financial support services.

A heavy burden on young minds: the global burden of mental and substance use disorders in children and youth.

BACKGROUND: Mental and substance use disorders are common and often persistent, with many emerging in early life. Compared to adult mental and substance use disorders, the global burden attributable to these disorders in children and youth has received relatively little attention. METHOD: Data from the Global Burden of Disease Study 2010 was used to investigate the burden of mental and substance disorders in children and youth aged 0-24 years. Burden was estimated in terms of disability-adjusted life years (DALYs), derived from the sum of years lived with disability (YLDs) and years of life lost (YLLs). RESULTS: Globally, mental and substance use disorders are the leading cause of disability in children and youth, accounting for a quarter of all YLDs (54.2 million). In terms of DALYs, they ranked 6th with 55.5 million DALYs (5.7%) and rose to 5th when mortality burden of suicide was reattributed. While mental and substance use disorders were the leading cause of DALYs in high-income countries (HICs), they ranked 7th in low- and middle-income countries (LMICs) due to mortality attributable to infectious diseases. CONCLUSIONS: Mental and substance use disorders are significant contributors to disease burden in children and youth across the globe. As reproductive health and the management of infectious diseases improves in LMICs, the proportion of disease burden in children and youth attributable to mental and substance use disorders will increase, necessitating a realignment of health services in these countries.

Modelling biological invasions: Individual to population scales at interfaces.

Extracting the population level behaviour of biological systems from that of the individual is critical in understanding dynamics across multiple scales and thus has been the subject of numerous investigations. Here, the influence of spatial heterogeneity in such contexts is explored for interfaces with a separation of the length scales characterising the individual and the interface, a situation that can arise in applications involving cellular modelling. As an illustrative example, we consider cell movement between white and grey matter in the brain which may be relevant in considering the invasive dynamics of glioma. We show that while one can safely neglect intrinsic noise, at least when considering glioma cell invasion, profound differences in population behaviours emerge in the presence of interfaces with only subtle alterations in the dynamics at the individual level. Transport driven by local cell sensing generates predictions of cell accumulations along interfaces where cell motility changes. This behaviour is not predicted with the commonly used Fickian diffusion transport model, but can be extracted from preliminary observations of specific cell lines in recent, novel, cryo-imaging. Consequently, these findings suggest a need to consider the impact of individual behaviour, spatial heterogeneity and especially interfaces in experimental and modelling frameworks of cellular dynamics, for instance in the characterisation of glioma cell motility.

The heritability of delusional-like experiences.

OBJECTIVE: Delusional-like experiences (DLE) are common in the general community and are associated with a family history of mental illness. The aim of this study was to estimate the heritability of DLE. METHOD: The Peter's Delusional Inventory (PDI) was administered to a population-based cohort of mothers (n = 2861, aged 35-67 years) and their adult offspring (n = 3079, aged 18-23 years). Heritability of DLE was estimated from the sum scores of the 21 item PDI under the assumption that the covariance between mother-offspring scores is attributable to shared additive genetic factors. RESULTS: The means (medians and standard deviations) for the total PDI scores for the mothers and their offspring were 3.6 (3.0, 3.0) and 5.0 (4.0, 3.5), respectively. The Pearson correlation coefficient between mother and offspring PDI scores was 0.17 (P < 0.001). The heritability was estimated to be 0.35 (standard error 0.04). CONCLUSION: Heritable factors contribute to over a third of the variance of PDI scores in this population. In light of the association between a family history of a wide range of mental disorders and DLE, these experiences may represent a useful quantitative endophenotype for genetic studies of common mental disorders in population settings.

Graph 'texture' features as novel metrics that can summarize complex biological graphs.

Objective.Image texture features, such as those derived by Haralicket al, are a powerful metric for image classification and are used across fields including cancer research. Our aim is to demonstrate how analogous texture features can be derived for graphs and networks. We also aim to illustrate how these new metrics summarize graphs, may aid comparative graph studies, may help classify biological graphs, and might assist in detecting dysregulation in cancer.Approach.We generate the first analogies of image texture for graphs and networks. Co-occurrence matrices for graphs are generated by summing over all pairs of neighboring nodes in the graph. We generate metrics for fitness landscapes, gene co-expression and regulatory networks, and protein interaction networks. To assess metric sensitivity we varied discretization parameters and noise. To examine these metrics in the cancer context we compare metrics for both simulated and publicly available experimental gene expression and build random forest classifiers for cancer cell lineage.Main results.Our novel graph 'texture' features are shown to be informative of graph structure and node label distributions. The metrics are sensitive to discretization parameters and noise in node labels. We demonstrate that graph texture features vary across different biological graph topologies and node labelings. We show how our texture metrics can be used to classify cell line expression by lineage, demonstrating classifiers with 82% and 89% accuracy.Significance.New metrics provide opportunities for better comparative analyzes and new models for classification. Our texture features are novel second-order graph features for networks or graphs with ordered node labels. In the complex cancer informatics setting, evolutionary analyses and drug response prediction are two examples where new network science approaches like this may prove fruitful.

Genomic Characterization of Mycoplasma arginini Isolated from a Housefly on a Dairy Farm and Comparison with Isolates from Bovine Milk and Lung Tissue.

Mycoplasma mastitis can be highly contagious, unresponsive to treatment, and cause severe economic problems in affected herds. Notable routes of Mycoplasma spp. transmissions are contaminated milking equipment and animal contact through respiratory secretions. Only a few studies report the environment as a possible source of infection. Our group studied the presence of pathogens in houseflies (Musca domestica) in a New York State dairy in the United States. Among others, a Mycoplasma spp. was found in the gut of a housefly captured in the sick pen and identified as M. arginini. Here, we characterized its genome and investigated its relatedness with eight isolates from milk, one isolate from lung tissue collected in the same dairy, and five other dairies in New York State. We applied whole-genome sequencing and phylogenetic analysis based on the sequences of the 16S rRNA gene and 76 conserved proteins. We also assessed an in silico virulence profile by considering a panel of 94 putative virulence genes. As a result of the genome analysis, the housefly M. arginini isolate was highly similar to the milk isolates; interestingly, the similarity was highest with M. arginini isolated from milk on the same dairy farm where the housefly was captured. The housefly and milk M. arginini isolates possessed 54 of the 94 pathogenicity genes considered. Our data support the hypothesis that houseflies are carriers of Mycoplasma spp. and can be considered within the possible roots of environmental transmission of infection in dairy cows. Nevertheless, M. arginini pathogenicity will need to be investigated with dedicated studies. IMPORTANCE It is critical to control the spread of bovine mastitis caused by Mycoplasma spp., as this disease can be highly contagious and have a severe economic impact on affected dairies. A better understanding of possible transmission routes is crucial for infection control and prevention. Based on our data, the composite milk isolates are genetically similar to the housefly isolate. This provides evidence that the same Mycoplasma species found in milk and associated with mastitis can also be isolated from houseflies captured in the dairy environment.

Investigating prostate cancer tumour-stroma interactions: clinical and biological insights from an evolutionary game.

BACKGROUND: Tumours are made up of a mixed population of different types of cells that include normal structures as well as ones associated with the malignancy, and there are multiple interactions between the malignant cells and the local microenvironment. These intercellular interactions, modulated by the microenvironment, effect tumour progression and represent a largely under-appreciated therapeutic target. We use observations of primary tumour biology from prostate cancer to extrapolate a mathematical model. Specifically, it has been observed that in prostate cancer three disparate cellular outcomes predominate: (i) the tumour remains well differentiated and clinically indolent--in this case the local stromal cells may act to restrain the growth of the cancer; (ii) early in its genesis the tumour acquires a highly malignant phenotype, growing rapidly and displacing the original stromal population (often referred to as small cell prostate cancer)--these less common aggressive tumours are relatively independent of the local microenvironment and (iii) the tumour co-opts the local stroma--taking on a classic stromagenic phenotype where interactions with the local microenvironment are critical to the cancer growth. METHODS: We present an evolutionary game theoretical construct that models the influence of tumour-stroma interactions in driving these outcomes. We consider three characteristic and distinct cellular populations: stromal cells, tumour cells that are self-reliant in terms of microenvironmental factors and tumour cells that depend on the environment for resources, but can also co-opt stroma. RESULTS: Using evolutionary game theory we explore a number of different scenarios that elucidate the impact of tumour-stromal interactions on the dynamics of prostate cancer growth and progression, and how different treatments in the metastatic setting can affect different types of tumours. CONCLUSION: The tumour microenvironment has a crucial role in selecting the traits of the tumour cells that will determine prostate cancer progression. Equally important treatments like hormone therapy affect the selection of these cancer phenotypes making it very important to understand how they impact prostate cancer's somatic evolution.

Pathogens associated with houseflies from different areas within a New York State dairy.

Houseflies (Musca domestica) are nonbiting muscoids of importance because they can be mechanical vectors of many kinds of pathogens such as bacteria, protozoa, viruses, and helminth eggs. This study aimed to evaluate the bacterial communities associated with houseflies captured in 3 different areas on a dairy farm located in New York State. Variations in the bacterial community were also evaluated based on the flies' sex and external or internal location where the bacteria were isolated. A total of 101 flies were collected: 27 flies from the sick pen, 42 from calf hutches, and 32 from the milking parlor. A total of 485 organisms were isolated, 233 (48.0%) from 53 female flies and 252 (52.0%) from 48 male flies. Most (74%) bacteria were found in the internal parts of the flies, with only 26% isolated from the external surfaces. The number of isolates detected per fly ranged between 1 and 11. A total of 392 bacteria were identified at the species level. We isolated 26 species reported to be bovine contagious or environmental mastitis pathogens. Within the group of organisms considered contagious, we isolated Staphylococcus aureus and Mycoplasma arginini. This was the first time that a Mycoplasma species was isolated from houseflies. We identified 5 organisms considered foodborne pathogens that affect human health: Salmonella spp., Escherichia coli, Staph. aureus, Bacillus cereus, and Bacillus subtilis. Four of the organisms isolated in this study were also linked with milk spoilage, including Pseudomonas aeruginosa, Bacillus cereus, Bacillus licheniformis, and Paenibacillus lactis. This study confirmed that houseflies carry a high bacterial diversity, including organisms associated with animal infections, organisms that could be a concern for public health, or organisms that could negatively affect milk quality.