Recent Trends of Antibiotic Resistance in Staphylococcus aureus Causing Clinical Mastitis in Dairy Herds in Abruzzo and Molise Regions, Italy

This study aimed to investigate the recent trends of antibiotic resistance (AR) prevalence in Staphylococcus aureus isolated from the milk of animals with clinical mastitis in areas of the Abruzzo and Molise regions in Central Italy. Fifty-four S. aureus isolates were obtained from routine testing for clinical mastitis agents carried out in the author institution in the years 2021 and 2022 and were analyzed for phenotypic resistance to eight antibiotics recommended for testing by European norms and belonging to the antibiotic classes used for mastitis treatment in milk-producing animals. Moreover, the presence of 14 transferable genetic determinants encoding resistance to the same antibiotics was analyzed using qPCR tests developed in this study. Phenotypic resistance to non-β-lactams was infrequent, with only one 2022 isolate resistant to clindamycin. However, resistance to the β-lactam cefoxitin at concentrations just above the threshold of 4 µg/mL was observed in 59.2% of isolates in both years, making these isolates classifiable as methicillin-resistant. The AR genotypes detected were the blaZ gene (50% of 2021 isolates and 44.4% of 2022 isolates), aphA3-blaZ- ermC/T (one 2021 isolate), aphA3-ant6-blaZ-ermC/T (one 2021 isolate), blaZ-ermB (one 2022 isolate) and mecA-mph (one 2022 isolate). An inquiry into the veterinarians who provided the samples, regarding the antimicrobials prescribed for mastitis treatment and criteria of usage, indicated a possible causal relation with the AR test results. The occurrence of AR genotypes did not increase in time, most probably reflecting how mastitis was treated and prevented in farms. However, the frequently observed cefoxitin resistance needs to be explained genotypically, further monitored and limited by modifying antibiotic usage practices. The identification of a mecA-positive isolate in 2022 suggests further investigation if this genotype is emerging locally.

Foodborne outbreaks surveillance in hospitals and nursery homes: investigation on catering data

Background

Healthcare associated foodborne outbreaks (HA-FBO) can result from exposure to contaminated food in premises where highly vulnerable patients are cared, including hospitals and nursery homes. The probability of developing severe foodborne diseases such as invasive listeriosis is much higher for susceptible populations. There is limited knowledge on the data on food exposures that could be used to investigate HA-FBOs. There is also lack of data relating to specific policies in the health facilities aimed to prevent the administration of potentially risky foods, possibly bringing them from home.

Methods

This study was in the framework of One Health EJP Project NOVA. A semistructured questionnaire was administered to 4 general hospitals, 1 specialist clinic and 3 nursing homes located in the Abruzzo and Molise regions, Italy. The questionnaire included 25 questions in 3 sections (I. General organization of the catering service; II. Food menu data; III. Food from home).

Results

In most facilities (75%) external catering companies used in-house kitchens. Trace-back of food to individual patients was possible in 5 premises out of 8 (62.5%), but only in 1 nursery home out of 3 (33.3%). Data were collected in electronic format (hospitals) or paper (nursery homes) and stored 1-12 months. Food at risk of Listeria monocytogenes were not excluded from the menus, such as pre-sliced cooked meat products (served in 4 out of 8 premises, 50%), smoked fish (20%), soft cheese (20%). The consumption of food brought from home was possible in “special occasions”, mostly in the nursery homes (66.6%).

Conclusions

In case of HA-FBO it could be difficult to trace back the food particularly in the nursery homes where food data are not individually collected and usually on paper. More studies are needed in order to understand the effective exposure to foodborne pathogens, given that some types of foods considered by EFSA as at high risk of microbial contamination are commonly served.

Key messages

Served food could not be traced back to the patient mostly in nursery homes. Foods at risk of Listeria monocytogenes contamination are commonly served to patients and residents.

First report of Trichinella pseudospiralis in a wolf (Canis lupus italicus)

Within the genus Trichinella, Trichinella pseudospiralis is the only recognized non-encapsulated species known to infect mammals and birds. In October 2020, larvae recovered from muscle tissues of a wolf (Canis lupus italicus) originating from Molise Region, Central Italy, were molecularly confirmed as those of Trichinella britovi and T. pseudospiralis. This is the first detection of T. pseudospiralis from a wolf. In Italy, this zoonotic nematode was detected in a red fox (Vulpes vulpes), three birds (Strix aluco, Athene noctua, Milvus milvus) and five wild boars (Sus scrofa), and was also identified as the etiological agent of a human outbreak of trichinellosis in 2015. Since T. pseudospiralis is rarely reported from carnivore mammals in comparison to the encapsulated species frequently detected in these hosts, this finding opens the question of the role of carnivores as reservoirs for this parasite.

Contamination of honey by oxytetracycline from pig manure

Although the use of antimicrobial is not allowed in bee industry according to current EU legislation, antimicrobial residues are often detected in honey doomed to human consumption. This study aims to investigate if bees living in hives located nearby tanks filled with pig manure containing residues of oxytetracycline, would naturally harvest water from it, thus contaminating their honey. Data from this experiment were compared with those originating from direct contamination with oxytetracycline through the beehive feeders. Bees did not harvest water from manure, even during the warmest days of summer. Instead, antimicrobial residues were evidenced and quantified in honey from hives directly contaminated with oxytetracycline. Interestingly, antimicrobial residues were also observed in honey from untreated hives thus suggesting that illegal treatments can cause contamination, albeit at low levels, of honey produced in legally-untreated neighboring hives.

Confirmation of crayfish plague in Italy: detection of Aphanomyces astaci in white clawed crayfish

In the summer of 2009, high levels of mortality among white clawed crayfish Austropotamobius pallipes were observed in 3 watercourses of central Italy. PCR and culture methods were used to detect the causative agent of the disease. Two strains of Aphanomyces spp. were isolated and identified by PCR and DNA sequencing as Aphanomyces astaci and A. repetans. This is the first crayfish plague outbreak in Italy to be confirmed by the isolation in culture of a pathogen from Austropotamobius pallipes.

The Rao's Brief Repeatable Battery and Stroop Test: normative values with age, education and gender corrections in an Italian population

The Brief Repeatable Battery of Neuropsychological Tests (BRB) is by far the most widely used instrument to estimate cognitive dysfunction in multiple sclerosis (MS) patients. However, the paucity of normative data currently limits its applicability. We administered the BRB to 200 healthy subjects to obtain normative values. Moreover, we assessed the influence of demographic factors on the test scores and calculated corrections for these relevant factors. To test executive functions not explored by the BRB, we also included the Stroop word-color task (ST). Higher educational level was associated with better performance on all the tests, except for the world list generation (WLG) and the ST, considering version A, and on Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT) and Selective Reminding Test-Delayed (SRT-D), considering version B. Females performed better than males on the WLG considering version A, and on the SRT-Long-Term Storage (SRT-LTS) and SRT-Consistent Long-Term Retrieval (SRT-CLTR) considering version B. Increasing age was associated with worse performance on the ST in version A, and on the SRT-LTS, SRT-CLTR and WLG in version B. Our data can improve the applicability of the BRB for both clinical and research purposes.