Pastern dermatitis outbreak associated with toxigenic and non-toxigenic Corynebacterium diphtheriae and non-toxigenic Corynebacterium ulcerans at a horse stable in Finland, 2021.

AIMS: Corynebacterium diphtheriae and Corynebacterium ulcerans, when producing toxin, are the cause of diphtheria, a potentially life-threatening illness in humans. Horses (Equus ferus caballus) are known to be susceptible to infection that may manifest clinically on rare occasions. In late 2021 and early 2022, specimens from five horses suffering from pastern dermatitis were cultured at the Laboratory of Clinical Microbiology at the Faculty of Veterinary Medicine, University of Helsinki, Finland. C. diphtheriae and/or C. ulcerans were recovered from all of these. This study aimed to (1) analyse the bacterial isolates and (2) describe the outbreak and identify possible sources of the infection and infection routes in the stable. METHODS AND RESULTS: Susceptibility testing, PCR for the tox gene, and Elek test for toxin production in PCR-positive isolates were performed. Whole genome sequencing was also conducted to achieve high-resolution strain typing. An epidemiological survey was done by means of a semi-structured interview of horses' caretaker, and contact tracing was done among people at the stable. Two tox gene-positive, toxin-producing C. diphtheriae belonged to sequence type (ST) 822. Other C. diphtheriae (n = 2, ST828) and C. ulcerans (n = 2, ST325 and ST838) isolates did not carry the tox gene. The epidemiological investigation explored numerous possible routes of transmission, but the definite source of infection was not identified. All established human contacts tested negative for diphtheriae. All horses recovered after antimicrobial treatment. CONCLUSIONS: Our study shows that C. diphtheriae and C. ulcerans may readily spread among horses at the same stable and complicate pastern dermatitis infections. These potentially zoonotic bacteria can cause outbreaks even in a country with a very low prevalence. Caretakers should be encouraged to wear gloves and practice good hand hygiene when treating infected skin lesions in horses.

Sulfur analyses and mineralogical data in the preliminary mine waste characterization.

The objective of this study was to investigate the use of the acid production potential (AP) calculation factor and seven different S analysis methods in the preliminary mine waste characterization by analyzing and comparing 48 Finnish mine waste samples. Special attention was paid on mineralogical aspects and data produced in the exploration phase of a mining project.According to our results, the abundance of sulfide species other than pyrite in Finnish mine waste suggests that the factor to calculate the AP should be considered based on mineralogy and would often be below 31.25. Therefore, the mineralogy-based determination of S should be preferred. However, the determination of S based on scanning electron microscope (SEM) mineralogy includes some uncertainties. Underestimation of S content may appear if not all S-bearing mineral particles have been detected, or if the amount of S is low in general. This uncertainty appears to be especially related to the samples containing elevated (> 9 wt%) amounts of serpentine, diopside, augite, and/or hornblende. Risk of overestimating AP is related to samples containing high amounts (> 4.13 wt%) of S-bearing minerals. These uncertainties can be reduced by inspecting that the SEM mineralogy-based S concentrations are in line with the energy dispersive X-ray spectrometer data. The aqua regia extractable S concentrations, which are often available in the exploration phase, appeared to be usable in the preliminary waste rock AP assessment and often comparable with the analytical total S values in the Finnish waste rock samples, especially when the samples did not contain any sulfate minerals. In contrast, the analytical sulfide S and the X-ray fluorescence methods may lead to an underestimation of AP.

Design parameters for nitrogen removal by constructed wetlands treating mine waters and municipal wastewater under Nordic conditions.

Nitrogen (N) loads from municipal and mine wastewater discharges typically increase N concentrations in recipient water bodies which should get more attention especially in cold-climate regions. This study compared N removal efficiency of six constructed wetlands (CWs) treating mine waters and three CWs polishing municipal wastewater. There were clear impacts of point source N loading to recipient water bodies in all cases studied and >300-fold increase in N was seen in some cases. First-order N removal coefficient was determined for seven of these CWs. All CWs studied were observed to remove N efficiently during the warm growing season but the amount of N released increased significantly during the cold season. Although some year-round purification was achieved by both peat-based and pond-type CWs, removal of nitrate + nitrite-N ((NO3- + NO2-)-N) was low during winter. The first-order N removal coefficient varied from 4.9 ·â€¯10-6 to 1.9 ·â€¯10-3 d-1 and showed that peat-based CWs were slightly more efficient in N removal than pond-type CWs. However, purification efficiency was steadier and higher for pond-type CWs, as lower hydraulic load or longer water residence time compensated for purification performance. Pond-type CWs showed mean removal efficiency of 59% and 46% for ammonium-N (NH4+-N) and (NO3- + NO2-)-N, respectively, whereas peatland-type CWs had lower removal efficiency for NH4+-N (mean of 26%) and in many cases negative removal for (NO3- + NO2-)-N. Correlation analysis revealed no clear, systematic relationship between temperature and N removal. However, in some CWs the highest correlation was between temperature and (NO3- + NO2-)-N, reflecting lower denitrification rate at lower temperature. More than 50% removal was found to require a hydraulic load below 10 mm d-1. In order to achieve 70% of NH4+-N removal, Ntot load lower than 75 g m-2 year-1 and a residence time longer than 80 d are needed in CWs in cold-climate regions.

Comparison of static and mineralogical ARD prediction methods in the Nordic environment.

Acid rock drainage (ARD) is a major problem related to the management of mining wastes, especially concerning deposits containing sulphide minerals. Commonly used tests for ARD prediction include acid-base accounting (ABA) tests and the net acid generation (NAG) test. Since drainage quality largely depends on the ratio and quality of acid-producing and neutralising minerals, mineralogical calculations could also be used for ARD prediction. In this study, several Finnish waste rock sites were investigated and the performance of different static ARD test methods was evaluated and compared. At the target mine sites, pyrrhotite was the main mineral contributing to acid production (AP). Silicate minerals were the main contributors to the neutralisation potential (NP) at 60% of the investigated mine sites. Since silicate minerals appear to have a significant role in ARD generation at Finnish mine waste sites, the behaviour of these minerals should be more thoroughly investigated, especially in relation to the acid produced by pyrrhotite oxidation. In general, the NP of silicate minerals appears to be underestimated by laboratory measurements. For example, in the NAG test, the slower-reacting NP-contributing minerals might require a longer time to react than is specified in the currently used method. The results suggest that ARD prediction based on SEM mineralogical calculations is at least as accurate as the commonly used static laboratory methods.

Human herpes virus 6 infection in pediatric organ transplant patients.

Transplant patients need lifelong immunosuppressive medication, but this reduces their defense mechanisms, making them prone to viral infections and reactivations. We aimed to clarify the prevalence and clinical manifestations of the human herpes virus 6 (HHV-6) infection in children after pediatric solid organ transplants. Clinical findings and viral loads were compared between primary HHV-6 infections and reactivations. The study comprised 47 kidney, 25 liver, and 12 heart transplant patients who underwent surgery from 2009 to 2014. HHV-6 antibodies were analyzed before surgery, and HHV-6 DNAemia tests were regularly carried out after the transplant using a real-time quantitative polymerase chain reaction method. We found the primary HHV-6 infection in 19 of 22 (86%) seronegative patients, and it was more common in patients under 3 years of age (79%) than over 3 (38%, P=.0002). Post-transplant HHV-6 DNAemia affected 48 of 84 (57%) patients and was significantly higher in primary infections than reactivations (P=.001), and 17 of 48 (35%) patients had symptoms when it was detected at a median of 2 weeks post-transplant. The HHV-6 infection was common after solid organ transplants, especially under 3 years of age, and it typically started 2 weeks after surgery. Testing for HHV-6 DNAemia is recommended shortly after transplantation, especially in patients with fever, diarrhea, rash, seizures, or abnormal liver enzyme tests.

Development of a new quantitative real-time HHV-6-PCR and monitoring of HHV-6 DNAaemia after liver transplantation.

A quantitative HHV-6 PCR (qPCR) assay was developed and compared to an "in-house" qualitative PCR and to the commercial quantitative Argene CMV, HHV6, 7, 8 R-gene™ test. Clinical specimens consisting of 127 whole blood and 57 cerebrospinal fluid (CSF) specimens were tested using the two qPCRs and the qualitative PCR in parallel. When the qualitative PCR was used as a "gold standard," the sensitivities of the qPCRs for the blood samples were 86% for the "in-house" qPCR and 76% for the Argene's test and the specificities were 96% and 92%, respectively. With CSF specimens the sensitivities were 92% and 80% and the specificities 98% and 82%, respectively. Furthermore, the two qPCRs were compared in the monitoring of liver transplant patients and retrospectively correlated to HHV-6 antigenaemia. In total, 223 blood specimens were tested. HHV-6 antigenaemia had been found in 21/36 (58%) patients and HHV-6 DNAaemia was demonstrated in 18/36 (50%). Viral loads by the "in-house" test varied from 280 to 19700 copies/ml (median 1200) and by Argene's test from 120 to 24070 copies/ml (median 458). The correlation of viral loads between the two qPCRs was good (R=0.94, p<0.01). The new in-house test was found to be reliable for the detection and quantitation of HHV-6 DNA in clinical specimens.