Association between endometritis and urocystitis in culled sows

Cystitis: significant associations between pathology, histology, and quantitative bacteriology in sows, a cross-sectional study

BACKGROUND

The importance of cystitis in pig production is controversial and sparse information is available on its frequency and etiology in sows. The aim of this study was to determine the prevalence of bacteriuria, macroscopical and histological lesions of the urinary bladder in culled sows. Urinary bladders and urine samples were obtained from 176 culled sows at slaughter. The urine samples collected by cystocentesis were analyzed to determine bacterial content and pathological findings, macroscopic as well as microscopic, of the bladder were recorded for each sow.

RESULTS

The prevalence of bacteriuria, defined by bacterial concentrations ≥ 103 colony forming units per mL of urine, was 34%. Escherichia coli was isolated from 69% of the samples with bacteriuria. Redness of the mucosa was the most frequently observed macroscopic change of the bladder. Intense redness and presence of pus was considered significant pathological changes and occurred in 27% of the urinary bladders. The histopathological examination showed that mononuclear cells were the predominant type of cell infiltration in the bladder mucosa, while neutrophils occurred in very few samples. The criteria for cystitis determined by histopathology were met in 46% of the samples. The criteria were based on presence of hyperemia, edema, and inflammatory cell reaction defined as 40 or more neutrophils or mononuclear cells per high power field. All three indicators of cystitis were significantly associated with each other (p < 0.05) at sow level.

CONCLUSION

This study shows that signs of cystitis are common in culled sows. The prevalence of cystitis was 34% based on bacteriological examination, 27% based on macroscopic examination and 46% based on histological examination. Significant associations were found between the three indicators of cystitis: bacteriuria, pathological and histological lesions of the bladder. Based on macroscopic changes and histopathology of the bladder, the cut-off of ≥ 103 colony forming units per mL of urine seems to be appropriate for assessing urine cultures obtained by cystocentesis.

General and comparative aspects of endometritis in domestic species: A review

Endometritis is a leading cause of sub- and infertility in domestic animal species. The healthy uterus is colonized by commensal bacteria, viruses and yeast/fungi that represent the nonpathogenic microbiota. A shift in the number or type of organisms accompanied by immune dysfunction, however, may trigger uterine infection and inflammation. Metritis is associated with inflammation of all uterine layers (endometrium, myometrium and perimetrium), whereas endometritis is a more superficial inflammation involving solely the endometrium. Endometritis generally occurs at two time points in domestic animal species, postpartum and postmating. Postpartum endometritis may chronically persist, either as a low-grade disease that often manifests as a vaginal discharge but not a systemic illness (in some species termed clinical endometritis) or sometimes subclinical where features are only detected by endometrial sampling. Contamination of the uterus at the time of mating occurs by direct deposition of semen (ejaculated or artificially inseminated) into the uterus. Improper drainage of the ejaculatory fluid or an inadequate immune response may result in persistent mating-induced endometritis. Both postpartum and postmating endometritis interferes with fertility by creating a suboptimal environment for embryo development and placentation, and chronic endometritis may have an impact on sperm survival and fertilization ability. In the postpartum animal, there may also be changes in milk production and maternal behaviour, which can affect offspring health and survival. Preventive strategies for endometritis largely depend on monitoring their known risk factors, which are sometimes specific with regard to the species. Effective, nonantibiotic therapy for endometritis is not available to date. Overall, extensive research has been performed in cattle and horses to unravel key aspects of endometritis, but in sows and bitches, the available literature is scant. Thus, the need and opportunity to investigate the condition vary considerably among domestic species and necessitate their comparative assessment. This article reviews general and comparative aspects of the diagnosis and classification, pathogenesis, preventive strategies and therapeutics of endometritis in domestic species with a specific focus on cows, mares, sows and bitches.

Reproductive health of the sow during puerperium

The modern hyperprolific sow is susceptible to metabolic disease and chronic inflammation. The most sensitive phase is parturition, when the sow experiences systemic inflammation and stress, and major changes in metabolism and endocrinology. Resolution of inflammation and stress needs to happen quickly to ensure good reproductive health during puerperium. If the sow fails to adapt to these changes, puerperal disease may occur. The economically most important puerperal disease complex is the postpartum dysgalactia syndrome (PPDS). Other puerperal diseases include infections of the urogenital tract. Diagnosis of PPDS and urogenital disease on-farm is challenging but several diagnostic methods, including clinical examination, behavioral observations, ultrasonography and biomarkers are available. Ultrasonography is an excellent tool for monitoring the health of the urogenital tract, the mammary gland, and uterine involution and guide further diagnostic interventions. Biomarkers such as Chromogranin A, tumor necrosis factor-α, and interleukin-6 represent promising tools to monitor general health and the systemic state of inflammation and oxidative stress of the sow. Nonsteroidal anti-inflammatory drugs, dopamine antagonists, and oxytocin are promising to address the symptoms of PPDS. Reducing of stress, improving nutrition and intestinal health, and supporting animal welfare-friendly husbandry help in the prevention of PPDS.

Untargeted Metabolomics Pilot Study Using UHPLC-qTOF MS Profile in Sows' Urine Reveals Metabolites of Bladder Inflammation

Urinary tract infections (UTI) of sows (characterized by ascending infections of the urinary bladder (cyst), ureters, and renal pelvis), are major health issues with a significant economic impact to the swine industry. The current detection of UTI incidents lacks sensitivity; thus, UTIs remain largely under-diagnosed. The value of metabolomics in unraveling the mechanisms of sow UTI has not yet been established. This study aims to investigate the urine metabolome of sows for UTI biomarkers. Urine samples were collected from 58 culled sows from a farrow-to-finish herd in Greece. Urine metabolomic profiles in 31 healthy controls and in 27 inflammatory ones were evaluated. UHPLC-qTOF MS/MS was applied for the analysis with a combination of multivariate and univariate statistical analysis. Eighteen potential markers were found. The changes in several urine metabolites classes (nucleosides, indoles, isoflavones, and dipeptides), as well as amino-acids allowed for an adequate discrimination between the study groups. Identified metabolites were involved in purine metabolism; phenylalanine; tyrosine and tryptophan biosynthesis; and phenylalanine metabolism. Through ROC analysis it was shown that the 18 identified metabolite biomarkers exhibited good predictive accuracy. In summary, our study provided new information on the potential targets for predicting early and accurate diagnosis of UTI. Further, this information also sheds light on how it could be applied in live animals.

[Pathomorphology und microbiology of the urogenital tract of reproductively failed sows with positive deoxynivalenol result]

OBJECTIVE

Deoxynivalenol (DON) is a mycotoxin produced by fungi of Fusarium spp. It causes vomiting, but also exerts immunosuppressive effects that may be seen at local level e. g. the urogenital tract, in which case these effects are of relevance for fertility. The presented report describes a DON-associated pathomorphological picture of the urogenital tract in conjunction with the associated microbiological colonization.

MATERIAL AND METHODS

A total of 19 genital tracts (vagina, cervix, uterus, oviducts and ovaries) including the urinary bladder (n = 15) from reproductively failed gilts and different parity sows submitted from 8 farms in 2019/20 were examined pathomorphologically. DON as well as zearalenone (ZEA) were determined by using high performance liquid chromatography in 11 individual and 2 pooled (2 and 4 animals, respectively) bile samples. Microbiologic examinations of uterine (n = 17) and bladder (n = 12) specimens were additionally performed.

RESULTS

Nearly all vaginas (n = 16), cervixes (n = 15), uteri (n = 18) and numerous oviducts (n = 11) as well as urinary bladders (n = 11) displayed a mostly medium to severe chronical inflammation. In 17 cases, ≥ 2 organs were affected. Microbiologic evaluation revealed a usually mixed flora of several gram-negative and gram-positive bacterial species with E. coli, Streptococcus spp., Aeromonas spp. and Enterococcus spp. being the predominant species. A total of 8 individual and both pooled bile samples were found DON-positive (75.5 to > 200.0 µg/l). In a subset of the DON-positive samples, ZEA was simultaneously detected at low concentrations (6.57-21.20 µg/l).

CONCLUSION AND CLINICAL RELEVANCE

The results of the present study allow for the postulation that DON may cause fertility problems. Subsequent pathomorphological examinations of genital organs and the urinary bladder are recommended. When ≥ 2 organs are chronically inflamed and the uteri are additionally microbiologically positive, a contribution of DON may be assumed and confirmation via bile analysis is warranted.

Urinary tract infections in culled sows from Greek herds: prevalence and associations between findings of histopathology, bacteriology and urinalysis

Background

Urinary tract infections (UTI) of sows characterized by cystitis, which may progress to ureteritis and pyelonephritis, can affect their productivity, longevity and welfare. In this study, we determined the prevalence of UTI by histopathology and bacteriology. Furthermore, we investigated possible associations between histologically confirmed cystitis and the results of urinalysis and urine cultures in culled sows from three farrow-to-finish herds in Greece.

Materials and methods

One hundred eighty-five routinely culled sows were included in the study. Their urinary bladder was collected from abattoirs and subjected to histopathology. Furthermore, urinalysis and urine cultures were performed on urine samples aseptically collected from the bladders.

Results

Histologically confirmed cystitis was evident in 85/185 (45.94%) culled sows. Among those, 44 (51.76%) suffered from acute and 41 (48.24%) from chronic inflammation. The majority of positive urine cultures were due to colonization of the urinary tract with E.coli, which accounted for 55.81% of the total cases, followed by Staphylococcus spp. which accounted for 18.60% of detected infections. Evidence of cystitis was associated with bacteriuria and sows with bacteriuria were 2.30 (P = 0.03, 95% CI: 1.10–4.83) times more likely to have histologically confirmed cystitis compared to sows with negative urine cultures. Bacteriuria was associated with proteinuria (P < 0.01, OR = 9.72, 2.63–35.88), increased urine pH (P < 0.01, 3.40, 1.10–10.56) and presence of sediment (P < 0.01, 6.00, 1.50–23.76) in urine. Sows with proteinuria had 9.72 (P < 0.01, 2.63–35.88) times higher odds of bacteriuria than those without. Histologically defined cystitis was associated with proteinuria (P < 0.01, 2.03–13.20) and decreased urine pH (P < 0.01, 0.13–0.72). Sows with proteinuria were 5.18 (P < 0.01, 2.03–13.2) times more likely to have histological lesions consistent with cystitis, than those without. For one unit increase in pH, it was 3.20 (P = 0.006, 1.39–7.69) times less likely for a sow to have chronic or acute cystitis compared to absence of cystitis.

Conclusion

In the studied population, UTI affected almost one out of two culled sows. Bacteriuria, which was more common among sows with UTI than those without, was mainly ascribed to members of the intestinal and environmental bacteria. Proteinuria and the existence of urine sediment which were associated with UTI, could be used as proxy traits for UTI in live sows.

Identification through MALDI-TOF mass spectrometry and antimicrobial susceptibility profiling of bacterial pathogens isolated from sow urinary tract infection

BACKGROUND

Urinary tract infection (UTI) is a common disease in sows due to intensification of pig production. Despite direct economic losses, UTI prevalence and respective microbial identification are still poorly studied.

OBJECTIVE

The aims of this study were to identify the causative agents of UTI in sows through MALDI-TOF MS and to characterize their antimicrobial resistance profiles.

MATERIALS AND METHODS

Urine samples from 300 sows of three herds from São Paulo State (Brazil) were screened for UTI; suggestive samples were submitted to bacterial isolation. Species identification was performed by MALDI-TOF MS and susceptibility profiles were determined using disc diffusion method.

RESULTS

128 samples suggestive of UTI were analyzed; 48% of the animals presented UTI caused by a single pathogen, while the remaining 52% presented mixed infection. Escherichia coli stood out with the highest frequency among both single and mixed infections. The Gram-positive were exclusively associated with 27% of single infections. The mixed infections were further classified into 49 profiles. The high frequency of multiresistant profiles stood out for most of the studied isolates.

CONCLUSIONS

MALDI-TOF MS enabled the identification of rare pathogens related to UTI which may represent higher risk for porcine health, especially considering high frequency of multiresistant profiles.

Avaliação histopatológica de órgãos reprodutivos e bexiga de fêmeas suínas descartadas

Em um sistema intensivo de produção de suínos, as falhas reprodutivas são uma das principais razões de descarte de matrizes e queda nos índices produtivos. A infecção urinária (cistite) e as endometrites são consideradas importantes causas de descarte em fêmeas suínas, por terem consequências reprodutivas relevantes e elevarem a taxa de reposição do plantel. O presente estudo teve o objetivo de avaliar o aparelho reprodutivo e a bexiga de fêmeas suínas de descarte normal de granjas, bem como investigar a existência de relação entre as patologias encontradas. Foram examinadas 79 matrizes suínas oriundas de 20 rebanhos localizados no Estado de Santa Catarina. De cada fêmea foram coletados os ovários, fragmentos de útero e bexiga. Dentre as fêmeas avaliadas, 32 (40,5%) tinham diferentes graduações de cistite, 24 (30,4%) tinham algum tipo de inflamação uterina, e 9 (11,4%) estavam em anestro, com ovários inativos. Contudo, não foi observada dependência significativa entre cistite e endometrite nas amostras analisadas.

Urinary tract infections in sows in Italy: accuracy of urinalysis and urine culture against histological findings

In order to investigate the prevalence of urinary tract infections (UTI) in sow, lower urinary tract (LUT), kidney and urine samples were collected at slaughterhouse from 65 multiparous culled sows. Histopathology was performed on urethra, urinary bladder and -kidney sections. Urine collected by cystocentesis was analysed for physical and biochemical parameters, in addition to microscopic examination of the sediment and quantitative culture ( > 10(5) CFU/ml urine). The diagnostic accuracy of urinalysis and urine culture was calculated for the parameters that correlated with histological diagnosis: bilateral chronic lesions were found in 54 per cent of kidney samples and diffuse/multifocal lymphoplasmacytic infiltration of the submucosa in 53 per cent of the bladder and 68 per cent of the urethra samples. In 49 per cent of cases, the co-occurrence of bladder and urethra lesions was statistically significant (P < 0.009). Turbid urine (80 per cent sensitivity, 50 per cent specificity), > 5 white blood cells per high-power field (34 per cent sensitivity, 90 per cent specificity), intracellular or free bacteria (43 per cent sensitivity, 90 per cent specificity), and urine culture (49 per cent sensitivity, 97 per cent specificity) correlated with a finding of histopathological changes in the bladder. UTI appears to be common in culled sows in northern Italy. Compared with histopathology, urinalysis and urine culture showed low sensitivity but high specificity in detecting UTI.