Antibacterial and Biofilm Production Inhibition Activity of Thymus vulgaris L. Essential Oil against Salmonella spp. Isolates from Reptiles.

Salmonellosis is an infectious disease affecting both animals and humans. Antimicrobial resistant (AMR) and biofilm-producing Salmonella spp., frequently detected in reptiles (who can then act as asymptomatic carriers for warm-blooded animals), have developed resistance to biocides; this represents a warning for the emergence of biocide/antimicrobial cross-resistance. The aim of this study was to evaluate the efficacy of Thymus vulgaris L. essential oil (TEO) in inhibiting bacterial growth and biofilm production of Salmonella spp., which had been isolated from wild reptiles housed in a Zoo in Italy. The resistance profile against different classes of antibiotics showed that all the isolates were susceptible to the tested antibiotics, despite the presence of several AMR genes. All the isolates were also tested with aqueous solutions of TEO at different dilutions (5% to 0.039%). Interestingly, TEO proved effective both in inhibiting bacterial growth at low dilutions, with MIC and MBC values ranging between 0.078% and 0.312%, and in inhibiting biofilm production, with values ranging from 0.039% to 0.156%. TEO demonstrated effective bioactivity against the biofilm producer Salmonella spp., proving to be a valid disinfectant for the prevention of salmonellosis from reptiles, a possible source of infection for humans exposed to the reptiles' environment.

Evaluation of antibacterial oxygen/ozone mixture in vitro activity on bacteria isolated from cervico-vaginal mucus of cows with acute metritis.

Ozone is an oxidating gas showing a strong microbicidal activity on bacteria, fungi, viruses and protozoa. The aim of this study was to test the in vitro bacteriocidal action of an Ozone/Oxygen gas mixture on bacteria isolated from the cervico-vaginal mucus of cows affected by acute metritis. A pilot study was initially carried out on reference strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Mycoplasma bovigenitalium ATCC 19852) that were tested with three different treatments: a control positive baseline group (B-group) was incubated without gas treatment, a control positive oxygen group (O2-group) was treated with pure oxygen 100%, and the treated group (T-group) was exposed to a gaseous constant flow of an Ozone/Oxygen mixture, at 50, 35, 20 µg Ozone/ml and for 5, 3 and 1 min for every different Ozone concentration. In both positive control groups, the number of colony forming units (CFU) per ml was higher than 300 CFU/ml (E. coli and S. aureus) and higher than 30 CFU/ml for M. bovigenitalium, after incubation. The T-groups showed a minimal bacterial growth equal to or lower than 1 CFU/ml per plate. Based on the results of the pilot study, a second phase was performed on bacteria isolated from the cervico-vaginal mucus (Klebsiella pneumoniae, Enterobacter agglomerans, E. coli, Proteus mirabilis and M. bovigenitalium) using the lower concentration of 20 µg/ml of Ozone for the minimum exposure time of 1 min. The E. coli and S. aureus reference strains and the clinical isolates (K. pneumoniae, E. agglomerans, E. coli, P. mirabilis) were incubated at 37 °C for 48 h and the colonies were manually counted at 24 h and 48 h following inoculation. The cultures of M. bovigenitalium (both ATCC and clinical isolate) were incubated in a jar with modified atmosphere conditions with 5% CO2 at 37 °C for 4-7 days and colony counting was performed. The second phase showed a low number of CFUs (equal to or less than 7 CFU/ml) for the clinical isolates K. pneumoniae, E. agglomerans, E. coli and P. mirabilis, and, of note, for M. bovigenitalium, both ATCC and clinical isolate, the growth was completely inhibited. Ozone was demonstrated to have a bacteriocidal activity. This study encourages further research of in vivo application of low doses of gaseous Ozone for the treatment of metritis in cows by using minimal exposure times.

Alveolar osteitis associated with methicillin-resistant Staphylococcus epidermidis.

A critical point in dentistry is the empiric prescription of broad-spectrum antibiotics that could increase the levels of antimicrobial resistance. Alveolar osteitis is one of the most common post-op- erative complications in which antibiotic use is controversial. A 35-year-old female, with pain in the right mandibular region and treated with cefixime, was diagnosed with cracked tooth syndrome and pulpitis. The tooth was extracted and a massive purulent bleeding drainage was observed. Irrigation of the socket and a new therapy with azithromycin were done. Bacteriological analysis, a specific mecA gene PCR for the methicillin resistance, and the antimicrobial susceptibility test were per- formed on the bacterial isolate. A Staphylococcus epidermidis isolate was methicillin-resistant and showed resistance to erythromycin, azithromycin, clarithromycin, and sulfamethoxazole + trimeth- oprim. After 7 days, intraoral examination showed a complete resolution. The aim of this report is to suggest that systemic antibiotics may provide insufficient efficacy during alveolar osteitis, especially when caused by a multidrug-resistant organism.

Antimicrobial Activity of Essential Oils Evaluated In Vitro against Escherichia coli and Staphylococcus aureus.

The spread of extended-spectrum ß-lactamase-producing Escherichia coli and methicillin-resistant Staphylococcus aureus has caused a reduction in antibiotic effectiveness and an increase in mortality rates. Essential oils (EOs), known for their therapeutic efficacy, can be configured as novel broad-spectrum biocides. Accordingly, the bacteriostatic-bactericidal activity of Citrus Lemon (LEO), Pinus Sylvestris (PEO), Foeniculum Vulgaris (FEO), Ocimum Basilicum (BEO), Melissa Officinalis (MEO), Thymus Vulgaris (TEO), and Zingiber Officinalis Rosc. (GEO), at concentrations ranging from 1.25 to 40% (v/v), were tested in vitro against different E. coli and S. aureus strains using minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). The chemical compositions of the EOs were analyzed using GC/MS. The major components of all seven tested oils were limonene, α-pinene, anethole, estragole, citral, thymol, and zingiberene, respectively. We found that the bacteriostatic-bactericidal activity of the EOs was related to their chemotypes and concentrations, as well as the strain of the bacteria. A dose-effect correlation was found when testing GEO against S. aureus strains, whilst FEO was found to have no activity regardless of concentration. PEO, MEO, and BEO were found to have bactericidal effect with a MIC and MBC of 1.25% (v/v) against S. aureus strains, and LEO was found to have values of 1.25% (v/v) and 5% (v/v) against ATCC and clinical isolate, respectively. Interestingly, the antimicrobial activity of TEO was not related to oil concentration and the complete inhibition of growth across all E. coli and S. aureus was observed. Although preliminary, our data demonstrate the efficacy of EOs and pave the way for further investigations on their potential synergistic use with traditional drugs in the human and veterinary fields.

Prevalence of bacteriuria in cats with neurogenic bladder.

Urinary tract infections are defined as the adherence, multiplication, and persistence of an infectious agent within the urogenital system, causing an associated inflammatory response and clinical signs; instead, the presence of bacteria in urine as determined by positive bacterial culture (PUC) from a properly collected urine specimen, in the absence of clinical signs, is defined subclinical bacteriuria. Limited information on the prevalence of PUC in spinal cord injury cats affected by neurogenic bladder (NB) is available. On contrary, in NB dogs and humans the prevalence of bacteriuria is well documented. Moreover, while in humans information about bacteriemia associated with NB is already available, this aspect has never been studied in NB cats. The aim of this prospective study was to determine the prevalence of PUC in cats with NB, compared to animals affected by chronic kidney disease (CKD) and healthy cats. Furthermore, the prevalence of bacteriemia in cats with NB was evaluated. Fifty-one cats met the inclusion criteria: 12 cats were affected by NB, 22 had CKD and 17 were healthy. The prevalence of PUC was 58.33% and 18% in NB and CKD cat populations, respectively. All blood cultures were negative. The incomplete bladder emptying and the decreased resistance in the bladder wall could be considered predisposing elements to PUC in the NB feline population. The results of this study highlight, for the first time, an high prevalence of PUC in cats affected by NB, which was not found to be associated with bacteriemia.

Canine Parainfluenza Virus Infection in a Dog with Acute Respiratory Disease.

The canine infectious respiratory disease complex (CIRDC) is an endemic respiratory syndrome caused by different bacterial and viral pathogens. This report describes a case of canine parainfluenza virus infection in a vaccinated household dog with an acute respiratory symptom (dry cough), who underwent clinical and endoscopic investigations for a suspected foreign body. Cytological investigations carried out on the broncho-alveolar lavage fluid (BALF) tested negative for the presence of inflammatory or infectious processes and could have been misleading the clinicians. By the molecular analyses (PCR) carried out on the BALF, canine parainfluenza virus was exclusively detected without the simultaneous presence of other respiratory pathogens associated to CIRDC. This case report emphasizes the role of molecular diagnostics in the differential diagnosis of respiratory diseases, in order to avoid underestimating the circulation of the parainfluenza virus in the canine population.

Multidrug resistant Enterococcus faecium isolate from cholangitis/cholecystitis in a dog.

Mucocele and cholecystitis were diagnosed in a 10 year-old Shetland-sheepdog presenting aspecific clinical signs. Blood examinations and ultrasonography investigation were performed before to surgical approach, which allowed to collect biopsies and samples for bacteriological analyses. In addition, the patient was subjected to cholecystectomy. A multidrug resistant Enterococcus faecium was isolated from the gallbladder specimens. On the basis of antimicrobial susceptibility test, nitrofurantoin was used. The correct bacteriological diagnosis is necessary to set up effective therapy, influencing the patient's prognosis and improving the recovery time.

African Swine Fever-How to Unravel Fake News in Veterinary Medicine.

In recent years, fake scientific news has spread much faster through the Internet and social media within the so-called "infodemic". African Swine Fever (ASF) is a perfect case study to prove how fake news can undermine the public health response, even in the veterinary field. ASF is a highly contagious infective disease affecting exclusively domestic and wild pigs such as wild boars. ASF can cause social damage and economic losses both directly (due to the high mortality rate) and indirectly (due to international sanctions). Although ASF is not a threat to human health, since 2018 newspapers have often reported false or misleading news, ranging from misinterpreted findings/data to fake or alarmistic news. In some cases, fake news was spread, such as the use of snipers at the border of nations to kill wild boars, or those reports concerning possible risks to human health. In order to provide real and fact-based news on epidemics, some organizations have created easy-to-read infographic and iconographic materials, available on their websites, to help the readers identifying the fake news. Indeed, it is crucial that governments and scientific organizations work against fear and anxiety, using simple and clear communication.

Bayesian estimation of prevalence of Johne's disease in dairy herds in Southern Italy.

Johne's disease (JD) is a chronic granulomatous disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) causing important losses on dairy farms. In Italy, voluntary programs to control MAP infection in dairy cattle are implemented in the Northern part of the country, where several studies have been carried out. Conversely, the disease status has not been fully investigated in the Southern regions. The aims of this study were to (i) determine the herd-level true prevalence (HTP) and (ii) the conditional within herd animal-level prevalence (CWHP) of JD in selected dairy cattle herds in Southern Italy. Serum samples were taken from 27 farms and analysed using a commercial ELISA test. A Bayesian model was fitted to the data. The estimated posterior mean of HPT was 0.46 (89 % CI 0.25-0.67), while the mean CWHP was 0.03 (89 % CI: 0.012-0.045). The results presented in this study call for designing and implementing an effective JD control program at national level.

Natural Bovine Coronavirus Infection in a Calf Persistently Infected with Bovine Viral Diarrhea Virus: Viral Shedding, Immunological Features and S Gene Variations.

The evolution of a bovine coronavirus (BCoV) natural infection in a calf persistently infected with bovine viral diarrhea virus (BVDV) was described. The infected calf developed intermittent nasal discharge, diarrhea and hyperthermia. The total number of leukocytes/mL and the absolute differential number of neutrophils and lymphocytes resulted within the normal range, but monocytes increased at T28 (time 28 post-infection). Flow-cytometry analysis evidenced that the CD8+ subpopulation increased at T7 and between T28 and T35. BCoV shedding in nasal discharges and feces was detected up to three weeks post infection and high antibody titers persisted up to T56. The RNA BCoV load increased until T14, contrary to what was observed in a previous study where the fecal excretion of BCoV was significantly lower in the co-infected (BCoV/BVDV) calves than in the calves infected with BCoV only. We can suppose that BVDV may have modulated the BCoV infection exacerbating the long viral excretion, as well as favoring the onset of mutations in the genome of BCoV detected in fecal samples at T21. An extensive study was performed to verify if the selective pressure in the S gene could be a natural mode of variation of BCoV, providing data for the identification of new epidemic strains, genotypes or recombinant betacoronaviruses.

A simple pooling salivary test for SARS-CoV-2 diagnosis: A Columbus' egg?

Saliva is an appropriate specimen for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) diagnosis. The possibility of pooling samples of saliva, using non-invasive bibula strips for sampling, was explored employing Bovine coronavirus (BCoV) spiked saliva. In laboratory, up to 30 saliva-soaked strips were pooled in a single tube with 2 mL of medium. After quick adsorption with the medium and vortexing, the liquid was collected and tested with a quantitative molecular assay to quantify viral RNA genome copies. On testing of single and pooled strips, the difference between the median threshold cycles (Ct) value of test performed on the single positive saliva sample and the median Ct value obtained on the pool of 30 strips, was 3.21 cycles. Saliva pooling with bibula strips could allow monitoring of COVID-19 on a large scale, reducing costs for the health bodies in terms of medical material and skilled personnel. Finally, saliva sampling is noninvasive and less traumatic than nasopharyngeal swabs and can be self-collected.