Background In December, 2019, the newly identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, causing COVID-19, a respiratory disease presenting with fever, cough, and often pneumonia. WHO has set the strategic objective to interrupt spread of SARS-CoV-2 worldwide. An outbreak in Bavaria, Germany, starting at the end of January, 2020, provided the opportunity to study transmission events, incubation period, and secondary attack rates.Methods A case was defined as a person with SARS-CoV-2 infection confirmed by RT-PCR. Case interviews were done to describe timing of onset and nature of symptoms and to identify and classify contacts as high risk (had cumulative face-to-face contact with a confirmed case for ≥15 min, direct contact with secretions or body fluids of a patient with confirmed COVID-19, or, in the case of health-care workers, had worked within 2 m of a patient with confirmed COVID-19 without personal protective equipment) or low risk (all other contacts). High-risk contacts were ordered to stay at home in quarantine for 14 days and were actively followed up and monitored for symptoms, and low-risk contacts were tested upon self-reporting of symptoms. We defined fever and cough as specific symptoms, and defined a prodromal phase as the presence of non-specific symptoms for at least 1 day before the onset of specific symptoms. Whole genome sequencing was used to confirm epidemiological links and clarify transmission events where contact histories were ambiguous; integration with epidemiological data enabled precise reconstruction of exposure events and incubation periods. Secondary attack rates were calculated as the number of cases divided by the number of contacts, using Fisher's exact test for the 95% CIs.Findings Patient 0 was a Chinese resident who visited Germany for professional reasons. 16 subsequent cases, often with mild and non-specific symptoms, emerged in four transmission generations. Signature mutations in the viral genome occurred upon foundation of generation 2, as well as in one case pertaining to generation 4. The median incubation period was 4•0 days (IQR 2•3-4•3) and the median serial interval was 4•0 days (3•0-5•0). Transmission events were likely to have occurred presymptomatically for one case (possibly five more), at the day of symptom onset for four cases (possibly five more), and the remainder after the day of symptom onset or unknown. One or two cases resulted from contact with a case during the prodromal phase. Secondary attack rates were 75•0% (95% CI 19•0-99•0; three of four people) among members of a household cluster in common isolation, 10•0% (1•2-32•0; two of 20) among household contacts only together until isolation of the patient, and 5•1% (2•6-8•9; 11 of 217) among non-household, high-risk contacts.Interpretation Although patients in our study presented with predominately mild, non-specific symptoms, infectiousness before or on the day of symptom onset was substantial. Additionally, the incubation period was often very short ...

c Extended-spectrum ␤-lactamase (ESBL)-producing Escherichia coli strains are believed to be widely distributed among humans and animals; however, to date, there are only few studies that support this assumption on a regional or countrywide scale. Therefore, a study was designed to assess the prevalence of ESBL-producing E. coli in dairy cows and beef cattle in the southern part of Bavaria, Germany. The study population included 30 mixed dairy and beef cattle farms and 15 beef cattle farms. Fecal samples, boot swabs, and dust samples were analyzed for ESBL-producing E. coli using selective media. PCR was performed to screen for CTX-M and ampC resistance genes. A total of 598 samples yielded 196 (32.8%) that contained ESBL-producing E. coli, originating from 39 (86.7%) of 45 farms. Samples obtained from mixed farms were significantly more likely to be ESBL-producing E. coli positive than samples from beef cattle farms (fecal samples, P < 0.001; boot swabs, P ‫؍‬ 0.014; and dust samples, P ‫؍‬ 0.041). A total of 183 isolates (93.4%) of 196 ESBL-producing E. coli-positive strains harbored CTX-M genes, CTX-M group 1 being the most frequently found group. Forty-six additional isolates contained ampC genes, and 5 of the 46 isolates expressed a bla CMY-2 gene. The study shows that ESBL-producing E. coli strains are commonly found on Bavarian dairy and beef cattle farms. Moreover, to our knowledge, this is the first report of the occurrence of bla CMY-2 in cattle in Germany.

S, Sing A. Matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry as a tool for rapid diagnosis of potentially toxigenic Corynebacterium species in the laboratory management of diphtheriaassociated bacteria.

We examined 233 silage samples and found that molds were present in 206 samples with counts between 1 ؋ 10 3 and 8.9 ؋ 10 7 (mean, 4.7 ؋ 10 6 ) CFU/g. Mycophenolic acid, a metabolite of Penicillium roqueforti, was detected by liquid chromatography-mass spectrometry in 74 (32%) of these samples at levels ranging from 20 to 35,000 (mean, 1,400) g/kg. This compound has well-known immunosuppressive properties, so feeding with contaminated silage may promote the development of infectious diseases in livestock.Silage is frequently contaminated with fungi of the genera Monascus, Aspergillus, and Penicillium (14). One of the most common molds is Penicillium roqueforti, which can produce secondary metabolites such as roquefortine C, isofumiclavines A and B, PR toxin, macrofortines, and mycophenolic acid (5, 6, 10, 13). Roquefortine C has been detected frequently in silage (3,11,16), but little is known about the natural occurrence of the other mycotoxins, especially mycophenolic acid.Mycophenolic acid [6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-5-phthalanyl)-4-methyl-4-hexenoic acid] is a weak organic acid with antifungal, antibacterial, and antiviral activities (1, 2, 5). Its acute toxicity to mammals seems to be low: the calculated oral 50% lethal doses for rats and mice are 700 and 2,500 mg/kg, respectively (6). Mycophenolic acid is also a noncompetitive inhibitor of eukaryotic inosine monophosphate dehydrogenase (12) and blocks the conversion of inosine-5-phosphate and xanthine-5-phosphate to guanosine-5-phosphate. As T and B lymphocytes rely primarily on the de novo biosynthesis of purine rather than on the purine salvage pathway, mycophenolic acid blocks their proliferative response and inhibits both antibody formation and the production of cytotoxic T cells (9).Consumption of immunosuppressive compounds increases the risk of infectious diseases in livestock, but this risk cannot be accurately estimated without knowledge of naturally occurring immunosuppressants such as mycophenolic acid in silage. Therefore, we analyzed samples of grass and maize silage for the presence of P. roqueforti and mycophenolic acid.Samples. Samples of grass (n ϭ 98) and maize (n ϭ 135) silage partly visibly contaminated with molds were collected in Bavaria during 1997 and 1998. The mycobiota of the samples was determined quantitatively and qualitatively, and an aliquot of each silage type (ϳ500 g) was stored at Ϫ18°C until the analysis of mycophenolic acid.Mycological examination. An aliquot of 10 g of mechanically minced silage was suspended in 90 ml of sterile peptone water (10 g of casein peptone [Merck, Darmstadt, Germany], 8.5 g of sodium chloride [Merck], 1,000 ml of distilled water) and shaken at 20°C for 30 min. From this initial dilution (10 Ϫ1 ), subsequent dilutions (1:10) were made in sterile peptone water. For mold count determinations, 0.1-ml aliquots from the dilutions (10 Ϫ2 to 10 Ϫ4) were plated on Sabouraud 2% dextrose agar (Merck) supplemented with 400,000 IU of penicillin G (Sigma, Deisenhofen, Germany) and 40 mg of strept...

No abstract