Background
Studies checking antimicrobial resistance (AMR) of Listeria monocytogenes (Lm) are ongoing, coupled with disease surveillance. Lm resistant strains are reported and are increasing. The aim ...of the work was to investigate AMR of clinical strains of Lm collected from nine regions (mostly in Lombardy and Marche regions) from 2008 to 2020.
Methods
The dataset consisted of 233 Lm human strains collected from nine regions during the period 2008-2020. All the strains were tested using Sensititre™ Haemophilus Plate (Thermo Scientific, Milano, Italy). Results were expressed according to EUCAST breakpoints for Lm, S. pneumoniae and E. faecalis. Resistant strains were sequenced using Illumina platform, ABRicate was used to predict antimicrobial resistance genes and plasmids.
Results
Most of the strains were detected in Lombardy and Marche. The MIC results showed that 11 out of 233 strains were resistant, one to ampicillin, four to tetracycline and six to clarithromycin. Analysing the sequences, all the resistant strains showed to have a common antimicrobial resistant pattern (mprF, norB, FosX, (MLS)lin, lin and lmo0919). Genomic determinants for ampicillin and clarithromycin resistance were not detected. Indeed, only in 3 out of 4 resistant strains tetM was found. Meanwhile, plasmids were detected in 7 strains.
Conclusions
The distribution of the strains considered in this work did not reflect the real epidemiological situation in Italy, because their origin was mostly from two regions. The emergence of AMR also for Lm needs to be considered. Moreover, official breakpoints for Lm are not defined and to date limited to five antimicrobials excluding clarithromycin and tetracycline, where the pathogen showed resistance. Finally, the incongruence between phenotypic and genomic data suggests that the mechanisms involved in the resistance is not fully known especially for ampicillin. Further investigations are needed to improve the knowledge on Lm AMR.
Key messages
Monitoring AMR of Listeria monocytogenes is crucial, only effective drug in clinical cases should be used.
Further investigations are needed to explore the mechanisms involved in antimicrobial resistance of Listeria monocytogenes.
A free-living, striped dolphin Stenella coeruleoalba calf was stranded on the Latium coast of Italy in November 2009. Significant neuropathological findings included non-suppurative ...meningoencephalitis, microgliosis, neuronal degeneration, astrocytosis, and occasional multinucleate syncytia. Immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR) for Morbillivirus were positive exclusively from the brain, with morbilliviral antigen and nucleic acid being detected in neurons and, to a lesser extent, in astrocytes. A low neutralizing antibody titer (1:10) against Morbillivirus (Canine distemper virus, CDV) was also found in blood serum, with no simultaneous presence of serum antibodies to Brucella spp. or Toxoplasma gondii. Furthermore, no pathogenic bacteria were isolated from any tissue or biological sample. This is the second report of morbilliviral encephalitis in a striped dolphin stranded along the Italian coastline in a 16 yr period (1993 to 2009). The neurohistopathological, IHC, and biomolecular features of this case are of additional interest, as antigenic and genomic positivity were exclusively confined to the brain of this dolphin, which may have acquired morbilliviral infection either postnatally or transplacentally.
Listeria monocytogenes, Toxoplasma gondii and Brucella spp. can infect a wide range of species, including humans. In cetaceans, meningoencephalitis has been associated with T. gondii and Brucella ...spp. infection, whereas to our knowledge, L. monocytogenes infection has not previously been reported. Meningoencephalitis and L. monocytogenes, T. gondii and Brucella spp. were identified by means of both direct and indirect laboratory techniques in an adult female striped dolphin Stenella coeruleoalba found stranded in January 2015 on the Ligurian Sea coast, northwestern Italy. The animal was emaciated, and histopathology disclosed severe meningoencephalitis. The nature of the inflammatory response and intra-lesional protozoa were consistent with a mixed infection by L. monocytogenes, T. gondii and Brucella spp. We believe this is an unprecedented case of infection by 3 zoonotic pathogens and also the first bacteriologically confirmed case report of neurolisteriosis in cetaceans. Cerebral toxoplasmosis and neurobrucellosis may have led to the animal's disorientation and stranding, with L. monocytogenes having likely exacerbated the coinfection leading to the demise of this dolphin.
Ovine enzootic abortion is an infectious and contagious disease clinically characterized by abortion and weak neonates, affecting sheep and goats. The etiological agent is Chlamydophila (C.) abortus, ...which is considered one of the most common animal pathogens of small ruminants; it has important economic implications and represents a significant zoonotic risk. Clinical diagnosis is often difficult because the clinical signs and the pathological lesions are not specific for C. abortus infection, in fact they can also be observed as a result of infections with other abortifacient agents. Moreover, the involvement of the laboratory is necessary to perform the definitive diagnosis. One hundred and seventeen vaginal swabs from sheep with clinical signs related to chlamydial infection were examined by a PCR-RFLP assay that demonstrated high specifity and sensitivity. Six samples were positive for C. abortus. Vaginal swabs are easy to handle and allow to deal with biohazardous material in safety conditions.
In order to evaluate the relevance of multiple infections in domestic cats with Upper Respiratory Tract Disease (URTD) one hundred animals with clinical signs were investigated for detection of ...Feline Herpesvirus type-1 (FHV-1), Chlamydophila felis, Feline Calicivirus (FCV) and Bordetella bronchiseptica from mucosal swabs. Forty-seven cats were positive for FCV, 42 cats for FHV-1, 26 for B. bronchiseptica and 8 for C. felis. Dual or multiple infections were found in 33 of examined animals. Our results document that FCV and FHV-1 are the major recognized cause of URTD, although infections associated with other pathogens such as B. bronchiseptica or C. felis are also common in cats.
Morbilliviruses have emerged over the last 20 y as a group of pathogens which have dramatically impacted the health and conservation status of several free-ranging aquatic mammal species and ...populations worldwide (Kennedy, 1998; Di Guardo et al., 2005; Di Guardo, 2008; Van Bressem et al., 2009). Therefore, it is vital to accurately monitor the presence of morbilliviruses in stranded pinnipeds and cetaceans. Indirect evidence of (recent or past) exposure to these highly pathogenic agents can be achieved through the determination of specific anti-morbillivirus antibodies (Abs) in sera obtained from stranded animals (Duignan et al., 1994, 1995, 1997; Barrett et al., 1995; Di Guardo et al., 1995, 2010). Stranded animals provide a unique opportunity for monitoring the health status of free-ranging populations (Di Guardo et al., 1995; Cornaglia et al., 2000); however, carcasses are often found in a compromised preservation condition with advanced autolysis, making histo-pathological and immunohistochemical investigations for morbilliviruses and other viral and non-viral pathogens difficult. Despite these difficulties, morbilliviras infections have been diagnosed by means of a reverse transcriptase polymerase chain reaction (RT-PCR) technique in heavily autolyzed stranded bottlenose dolphins (Tursiops trunca-tus) (Krafft et al., 1995). Taking into account the limited amount of published work addressing this issue, we evaluated the time and temperature dependent variations of anti-morbillivirus antibody titres in a series of serum samples from three striped dolphins (Stenella coeruleoalba) stranded along the Italian coastline in 2007.
Sequence conservation among resistance genes (R genes) was exploited to identify 47 R gene analogues (RGAs) from sugar beet (Beta vulgaris L.). Using degenerate primers, 11 RGAs were amplified from ...genomic DNA and 7 from leaf or beet cDNA. Twenty-nine were selected from an EST sequencing program. Twenty-one RGAs contained structures similar to the nucleotide binding site (NBS) leucine rich repeat (LRR) domain, a motif commonly found in several R genes. Among the remaining RGAs, 19 revealed similarity to the serine (threonine) protein kinase domain of R genes, 4 showed features related to the LRR region of the rice disease resistance gene Xa21, 1 RGA resembled the sugar beet nematode resistance gene Hs1
pro-1
, and 2 had homologies to other gene products associated with disease resistance. For 20 EST-derived RGAs, transcript levels were compared in leaf and root tissue revealing organ-specific transcription in 7 cases. Thirty-three RGAs were spread over all nine sugar beet chromosomes, except for a cluster of nine closely linked RGAs on chromosome 7. The analysis of linkage between RGAs and loci for rhizomania and Cercospora resistance identified alleles associated with resistance in both cases.Key words: RGA, Beta vulgaris, NBSLRR, genetic linkage map, molecular marker.
Compliance to osteoporosis treatment with oral bisphosphonates is very poor. Intermittent intravenous bisphosphonate is a useful alternative, but this route is not readily available. Neridronate, a ...nitrogen-containing bisphosphonate that can be given intramuscularly (IM), was tested in a phase 2 clinical trial in 188 postmenopausal osteoporotic women randomized to IM treatment with 25 mg neridronate every 2 weeks, neridronate 12.5 or 25 mg every 4 weeks, or placebo. All patients received calcium and vitamin D supplements. The patients were treated over 12 months with 2-year posttreatment follow-up. After 12-month treatment, all three doses were associated with significant bone mineral density (BMD) increases at both the total hip and spine. A significant dose–response relationship over the three doses was observed for the BMD changes at the total hip but not at the spine. Bone alkaline phosphatase decreased significantly by 40–55% in neridronate-treated patients, with an insignificant dose–response relationship. Serum type I collagen C-telopeptide decreased by 58–79%, with a significant dose–response relationship (
P
< 0.05). Two years after treatment discontinuation, BMD declined by 1–2% in each dose group, with values still significantly higher than baseline at both the spine and the total hip. Bone turnover markers progressively increased after treatment discontinuation, and on the second year of follow-up the values were significantly higher than pretreatment baseline. The results of this study indicate that IM neridronate might be of value for patients intolerant to oral bisphosphonates and unwilling or unable to undergo intravenous infusion of bisphosphonates.
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