Nontuberculous mycobacteria (NTM) represent an increasingly prevalent etiology of soft tissue infections in animals and humans. NTM are widely distributed in the environment and while, for the most part, they behave as saprophytic organisms, in certain situations, they can be pathogenic, so much so that the incidence of NTM infections has surpassed that of Mycobacterium tuberculosis in developed countries. As a result, a growing body of the literature has focused attention on the critical role that drug susceptibility tests and infection models play in the design of appropriate therapeutic strategies against NTM diseases. This paper is an overview of the in vitro and in vivo models of NTM infection employed in the preclinical phase for early drug discovery and vaccine development. It summarizes alternative methods, not fully explored, for the characterization of anti-mycobacterial compounds.

The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs. The present study assessed the prevalence of Rickettsia spp., Babesia spp., Cytauxzoon spp. and Leishmania infantum infections in cat populations living in central Italy, by molecular and serological tools. A total of 286 healthy cats were randomly selected from catteries and colonies in central Italy. Peripheral blood and conjunctival swab (CS) samples were collected during surgical procedures for regional neutering projects. Sera were analysed by IFAT to detect anti-Rickettsia felis, R. conorii, Babesia microti and Leishmania IgG antibodies using commercial and home-made antigens. DNA extracted from buffy coats (BCs) was tested for Rickettsia spp., and Piroplasmida species, including Cytauxzoon spp. and Babesia spp. by PCR. Buffy coats and CS samples were assayed by a nested (n)-PCR for Leishmania spp. Sixty-two cats (21.67%) were seropositive to at least one of the tested pathogens. The serological assay revealed 23 (8.04%) and 18 (6.29%) positive cats for R. felis and R. conorii, respectively, with low titers (1/64–1/128). No antibodies against B. microti were detected. Neither Rickettsia nor Piroplasmida DNA were amplified using the specific PCR assays. Thirty-one cats (10.83%) tested positive to anti-Leishmania IgG, with titers ranging from 1:40 to 1:160 and 45 animals (15.73%) tested positive to Leishmania CS n-PCR, whereas none of the animals tested positive to BC n-PCR. Considering the results obtained by IFAT and CS n-PCR, a moderate agreement between the two tests was detected (κ = 0.27). The results of the serological and molecular surveys showed a moderate exposure to Leishmania in the investigated cats and highlighted the limited molecular diagnostic value of BC versus CS samples for this pathogen. Conversely no evidence supported the circulation of Cytauxzoon spp. in domestic cats, in contrast with previous detections in European wild cats in the same areas monitored. The low positive titres for R. felis in association with no DNA BC amplification prevent speculation on the exposure of feline populations to this FeVBP due to the cross-reactivity existing within spotted fever group rickettsiosis (SFGR).

This work aimed to evaluate the antimicrobial susceptibility of 87 Salmonella Infantis strains isolated in Italy from 2016 to 2019 along the food chain of broiler meat production and in humans and to determine the genetic profiles of the strains in order to establish a possible correlation with the antimicrobial pattern. All isolates were tested by the disk diffusion method to evaluate antimicrobial susceptibility toward sixteen antimicrobials, and the broth microdilution method was used to confirm extended spectrum β-lactamase (ESBL) production. PCR and pulsed field gel electrophoresis (PFGE) were applied to characterize ESBL-encoding and AmpC β-lactamase genes and to analyze the S. Infantis strains genetic profiles respectively. S. Infantis isolates showed high prevalence of resistance, in particular toward nalidixic acid (97.7%), tetracycline (96.5%), sulphamethoxazole/trimethoprim (91%) and cefepime (72.4%). The 80.5% of isolates were ESBL, cefotaxime-resistant, carrying the bla_CTX-M1 gene. The most prevalent PFGE profile was XbaI.0126 (35.6%). The remaining strains had a genetic homology from 81% to 97% with the XbaI.0126 profile. The strains belonging to these profiles were isolated from different matrices collected along the broiler food chain independently on the year and from the region and there was no correlation between the PFGE profiles and resistance patterns. We found two ESBL-producing S. Infantis strains with the same XbaI.2621 profile isolated from humans and from poultry feces, not yet reported in Italy. Our findings confirmed the diffusion of ESBL-multi drug resistant (MDR) S. Infantis along the broiler food chain and in humans and underlined the importance of continuous monitoring to control and to reduce the prevalence of this bacterium, applying a global One Health approach.

This study aimed to describe bacteria isolated from the reproductive tract of mares and to identify changes in antimicrobial susceptibility patterns to those antibiotics commonly used for the treatment of equine endometritis. A total of 4122 equine uterine swabs were collected from mares suffering from reproductive tract disorders in the period 2010–2017. Aerobic culture and antimicrobial susceptibility testing using agar disc diffusion were performed on each sample. Aerobic bacteria were isolated from 3171 of 4122 (76.9 per cent) samples. The most frequently isolated microorganisms were Escherichia coli (885/3171, 27.9 per cent) and Streptococcus equi subspecies zooepidemicus (791/3171, 24.9 per cent), confirming previous findings from the literature. Antimicrobial susceptibility patterns of E coli , S equi subspecies zooepidemicus and Klebsiella pneumoniae changed over time. A statistically significant decrease in antimicrobial efficacy of cefquinome against E coli was observed over the years, as well as of ampicillin, cefquinome and penicillin against S equi subspecies zooepidemicus . The high frequency of resistant bacteria isolated in the present work proceeds in the same way as indicated by surveillance data on the huge antibiotic use in Italy. As a result, testing and monitoring programmes of antimicrobial efficacy are crucial to consciously using antibiotics and preserving their effectiveness both for veterinary and human medicine.

Biofilm-forming ability is increasingly being recognized as an important virulence factor in several Staphylococcus species. This study evaluated the biofilm-forming ability of sixty canine derived clinical isolates of S. pseudintermedius, using three phenotypic methods, microtiter plate test (MtP), Congo red agar method (CRA) and tube adherence test, and the presence and impact of biofilm-associated genes (icaA and icaD). The results showed that icaA and icaD genes were detected concomitantly in 55 (91.7%) of 60 isolates. A majority (88.3%) of the strains screened had matching results by the tube adherence test, MtP and PCR analysis. Better agreement (95%) was found between the PCR-based analysis and the CRA. Results of the icaA and icaD gene PCRs showed good agreement with CRA results, with a kappa of 0.7. Comparing the phenotypic methods, the statistical analysis showed that the agreement among the phenotypical tests using categorical data was generally good. Considering two classes (biofilm producer and biofilm non-producer), the percentage of matching results between the CRA method and the tube adherence test and between the CRA method and the MtP was 93.3%. A concordance of 100% was revealed between the MtP and the tube adherence test. The results indicate a high prevalence of the ica genes within S. pseudintermedius isolates, and their presence is associated with in vitro formation of a biofilm. A combination of phenotypic and genotypic tests is recommended for investigating biofilm formation in S. pseudintermedius.