Multiclonal human origin and global expansion of an endemic bacterial pathogen of livestock.

Most new pathogens of humans and animals arise via switching events from distinct host species. However, our understanding of the evolutionary and ecological drivers of successful host adaptation, expansion, and dissemination are limited. Staphylococcus aureus is a major bacterial pathogen of humans and a leading cause of mastitis in dairy cows worldwide. Here we trace the evolutionary history of bovine S. aureus using a global dataset of 10,254 S. aureus genomes including 1,896 bovine isolates from 32 countries in 6 continents. We identified 7 major contemporary endemic clones of S. aureus causing bovine mastitis around the world and traced them back to 4 independent host-jump events from humans that occurred up to 2,500 y ago. Individual clones emerged and underwent clonal expansion from the mid-19th to late 20th century coinciding with the commercialization and industrialization of dairy farming, and older lineages have become globally distributed via established cattle trade links. Importantly, we identified lineage-dependent differences in the frequency of host transmission events between humans and cows in both directions revealing high risk clones threatening veterinary and human health. Finally, pangenome network analysis revealed that some bovine S. aureus lineages contained distinct sets of bovine-associated genes, consistent with multiple trajectories to host adaptation via gene acquisition. Taken together, we have dissected the evolutionary history of a major endemic pathogen of livestock providing a comprehensive temporal, geographic, and gene-level perspective of its remarkable success.

The frequency of the ACE I/D polymorphism in South America: a systematic review and meta-analysis.

Angiotensin-converting enzyme (ACE) is a key component of the renin-angiotensin system and plays an important role in homeostasis and maintenance of blood pressure. However, little is known about allele and genotypic frequencies, as well as phenotypic characteristics associated with ACE polymorphism genotypes in South American populations. This study aimed to verify the allelic predominance and genotype frequency of ACE I/D polymorphism in South America and its association with the main diseases and related conditions. We conducted a systematic review considering studies published in the last 25 years available in PubMed, Scielo, LILACS, LIPECS, Coleciona SUS, CUMED, BINACIS, IBECS, and MEDLINE databases, resulting in the inclusion of 121 studies. Quality of the studies was assessed according to the Strengthening the Reporting of Genetic Association (STREGA) guidelines. We mapped the frequency of the ACE I/D polymorphism in South American populations. 8,856 (32.1%) subjects were DD, 13,050 were ID (47.4%), and 5,644 were II (20.5%) carriers. The main associated conditions included systemic arterial hypertension and other cardiovascular conditions, cardiorespiratory or respiratory characteristics, physical activity level, kidney conditions, aging-related diseases, as well as different types of cancers and metabolic conditions. 61.1% of the studies found no significant association between the respective conditions investigated and the ACE I/D polymorphism. Considering DD genotype or D allele, 21.5% of the studies observed negative and 4.9% positive outcomes. Regarding ID genotype, 4.1% of the studies identified negative and 0.8% positive outcomes, and for II genotype or I allele, 4.1% of the results had negative and 10.7% positive associations.

An electrogram-guided transvenous temporary pacemaker implant simulator.

INTRODUCTION: Transvenous temporary pacemaker (TvTP) implantation is a critical procedure often performed under time limitations, playing a crucial role in patient survival. However, the amount of training provided for resident cardiologists is variable, due to the availability of patients. Thus, the use of simulators for this cardiologic procedure could be used as training tools. OBJECTIVE: The present study aimed to develop a simulator system for TvTP implantation based on electrograms, called ETTIS (Electrogram-guided Transvenous Temporary-pacemaker Implantation Simulator), and to evaluate its educational potential and cardiology residents' perceived learning efficacy as a training tool. METHODOLOGY: The development of the ETTIS involved three stages: (1) Adaptation of an anatomical mannequin; (2) Design and manufacture of electronic circuits and software capable of identifying the catheter contact site within the heart chambers and reproducing electrograms in both surfaces (mode-on) and intracavitary (mode-off); (3) To evaluate its educational potential, a modified Likert questionnaire was administered to nine cardiology experts. Additionally, to evaluate the perceived learning efficacy, another modified Likert questionnaire was given to six cardiology residents both before and after training with the ETTIS. Descriptive statistics with measures of position and dispersion were employed, and the weighted Kappa test was used for agreement analysis. RESULTS: A high rate of acceptance (over 90%) was found among experts who evaluated the ETTIS. The cardiology residents showed significant self-perceived learning gains, as evidenced by a lack of agreement between their responses to a questionnaire before and after training. CONCLUSION: The ETTIS is a promising tool for medical training, displaying both educational potential and efficacy. It has been shown to be effective in learning a variety of skills, including cardiac catheterization and electrophysiology. Additionally, the ETTIS is highly engaging and allows cardiology residents to practice in a safe and controlled environment.

Multinational Association of Supportive Care in Cancer (MASCC) expert opinion/guidance on the use of clinically assisted hydration in patients with advanced cancer.

PURPOSE: The provision of clinically assisted hydration (CAH) in patients with advanced cancer is controversial, and there is a paucity of specific guidance and so a diversity in clinical practice. Consequently, the Palliative Care Study Group of the Multinational Association of Supportive Care in Cancer (MASCC) formed a sub-group to develop evidence-based guidance on the use of CAH in patients with advanced cancer. METHODS: This guidance was developed in accordance with the MASCC Guidelines Policy. A search strategy for Medline was developed, and the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials were explored for relevant reviews/trials, respectively. RESULTS: Due to the paucity of evidence, the sub-group was not able to develop a prescribed guideline, but was able to generate a number of "expert opinion statements": these statements relate to assessment of patients, indications for CAH, contraindications for CAH, procedures for initiating CAH, and reassessment of patients. CONCLUSIONS: This guidance provides a framework for the use of CAH in advanced cancer, although every patient requires individualised management.

Active intervals between sets and exercise of resistance exercises potentiate the magnitude of post-exercise hypotension in middle-aged hypertensive women.

BACKGROUND: Walking/run promotes greater post-exercise hypotension (PEH) than resistance exercise (RE) which can be associated nitric oxide production. Then, we investigated if adding walking between RE increases PEH. METHODS: Thirteen hypertensive women (48 ± 1.9 years; 26.8 ± 0.3 kg/m2) performed five experimental sessions: 1-traditional RE with passive interval (PIBS); 2-RE with active interval between sets (AIBS); 3-RE with active interval between exercises (AIEX); 4-aerobic exercise (AE); 5-no exercise. Blood pressure was measured before and immediately after exercise and every 10 min of a 60-min post-exercise recovery period. Plasma nitrite (NO) and malondialdehyde (MDA) were also measured. RESULTS: AIBS, AIEX, and AE sessions promoted systolic PEH (12 ± 1.53; 16 ± 2.13; 18 ± 1.34 mmHg, respectively) and diastolic PEH (8 ± 1.38; 8 ± 0.79; 8 ± 0.58 mmHg). In AIBS, AIEX and AE sessions, significant PEH was noted at 10 or 20 min; in PIBS, PEH was significant only at 40 min. In the PIBS session, NO did not change, but presented higher values after AIBS, AIEX and AE sessions. MDA showed no changes between sessions. CONCLUSIONS: Passive or active intervals in resistance exercise promote PEH in hypertensive women. Active intervals shorten the PEH onset time as additional benefit.

Drug screening and development cascade for Chagas disease: an update of in vitro and in vivo experimental models.

Chagas disease is a tropical neglected disease that affects millions of people worldwide, still demanding a more effective and safer therapy, especially in its chronic phase which lacks a treatment that promotes substantial parasitological cure. The technical note of Romanha and collaborators published in 2010 aimed establish a guideline with the set of minimum criteria and decision gates for the development of new agents against Trypanosoma cruzi with the focus on developing new antichagasic drugs. In this sense, the present review aims to update this technical note, bringing the state of the art and new advances on this topic in recent years.

Detection of Trypanosoma evansi in jaguars (Panthera onca): insights from the Brazilian Pantanal wetland.

Trypanosoma evansi is a widespread and neglected zoonotic parasite that affects domestic and wild animals, causing a disease commonly known as "surra." The Brazilian Pantanal wetland is recognized as an enzootic area for this protozoan, yet recognizing the importance of reservoir hosts also in order to prevent zoonotic outbreaks. This study aimed to assess the occurrence of T. evansi in jaguars (Panthera onca) from the Brazilian Pantanal wetland and explore associated clinical and hematological manifestations. A total of 42 animals were screened by PCR and sequenced for species identification when positive. Trypanosoma evansi was detected in six free-ranging jaguars (six positive animals of 42 captures and 16 recaptures), representing the first molecular evidence of such infection in this animal species. Our findings suggest that jaguars may act as reservoir hosts of T. evansi in the Brazilian Pantanal wetland. The better understanding of the role of wildlife in the epidemiology of T. evansi is also of importance to future reintroduction and translocation programs toward wildlife conservation efforts.

Dirofilaria immitis and Onchocercidae spp. in wild felids from Brazil.

Among the species described within the Onchocercidae family, Dirofilaria immitis is regarded as the most common worldwide, causing severe and often fatal conditions in dogs, cats, and occasionally humans. Dirofilaria spp. are vectored by mosquitoes, simulids, and culicoids, with their epidemiology dependent on the geographical distribution of competent vectors. Eight species of Dirofilaria have been reported so far in Brazil, of which six parasitize non-human primates, deer, procyonids, and marsupials. Here, we investigated the occurrence of Onchocercidae in wild felids (i.e., Panthera onca, Puma concolor, Herpailurus yagouaroundi, Leopardus geoffroyi, Leopardus guttulus, Leopardus pardalis, Leopardus wiedii, Leopardus munoai) from different locations in Brazil. Overall, 82 samples (n = 63 blood; n = 19 tissues) were molecularly screened for cytochrome c oxidase subunit-1 (cox1) gene. Four (i.e., 4.8%) wild felid samples were positive, and at BLAST analysis, the obtained sequences showed varying percentage of nucleotide identity with the genera Brugia (i.e., 87-88%), Setaria (i.e., 89%), and D. immitis (i.e., 94.4%). Phylogenetic analyses clustered sequences obtained into three distinct clades, one with D. immitis and the remaining two with other Onchocercidae spp. Data herein obtained highlight the need for a more comprehensive understanding of the diversity and biology of Onchocercidae in South America in order to assess the potential impact that these species may have for domestic and wild animals, as well as humans.

Effect of different levels of whole corn germ on energy values and ileal digestibility in broilers.

This study evaluated the effects of broiler age (A) and levels of replacement (L) of control diet (CD) on the utilization of energy and nutrients of whole corn germ. 720 one-day-old broilers (b) were allocated at completely randomized design to six treatments and six replicates, in three assays: pre-starter (1-8 days, 10 b/cage), starter (15-22 days, 6 b/cage), and grower (28-35 days, 4 b/cage) phases. The treatments were: CD and four test diets (L): 100, 150, 200, 250, or 300 g kg-1 of the CD replaced by WCG levels. The data were adjusted to the response surface model. The stationary points for apparent energy metabolizable (AME) and AME corrected for nitrogen balance (AMEn) were: 4173 and 3591 kcal kg-1, respectively, and coefficients of gross energy (AMCGE), crude protein (AMCCP), dry matter (AMCDM), and ether extract (AMCEE) were: 49.3, 40.4, 72.6, and 61.3%, respectively; and Ileal digestibility coefficient of crude protein (IDCCP), dry matter (IDCDM), digestibility crude protein values (DCP), and digestibility dry matter value (DDM) were: 78.0, 57.96, 8.50, and 56.17%, respectively. The EP for AMEn was at 18 days of age, 28 g kg-1 WCG. There was a correlation between A and L on digestibility and metabolisability of nutrient's WCG.

Eugenia pohliana leaves essential oil inhibits fungal virulence and restores antibiotic efficacy in multidrug-resistant bacterial strains.

This study aims to investigate the essential oil from leaves of E. pohliana (EOEP) in regard to its chemical composition, antimicrobial and drug-enhancing activity, as well as the reduction of fungal virulence capacity. Chemical characterization using GC-MS showed as major components the sesquiterpenes δ-cadinene, Epi-α-Muurolol, and bicyclogermacrene. The results of antibacterial tests indicated that Staphylococcus aureus was more sensitive to EOEP, that also enhanced the efficacy of gentamicin, erythromycin, and norfloxacin. EOEP exhibited antifungal properties against Candida albicans, in addition to potentiating the effectiveness of fluconazole against Candida tropicalis. It showed anti-virulence effects in all fungal strains. These findings underscore Eugenia pohliana as a potential candidate for the prospection of novel therapeutic agents to treat infectious diseases caused by resistant microbes.

Automated treatment planning for whole breast irradiation with individualized tangential IMRT fields.

PURPOSES: This study aimed to develop and validate algorithms for automating intensity modulated radiation therapy (IMRT) planning in breast cancer patients, with a focus on patient anatomical characteristics. MATERIAL AND METHODS: We retrospectively selected 400 breast cancer patients without lymph node involvement for automated treatment planning. Automation was achieved using the Eclipse Scripting Application Programming Interface (ESAPI) integrated into the Eclipse Treatment Planning System. We employed three beam insertion geometries and three optimization strategies, resulting in 3600 plans, each delivering a 40.05 Gy dose in 15 fractions. Gantry angles in the tangent fields were selected based on a criterion involving the minimum intersection area between the Planning Target Volume (PTV) and the ipsilateral lung in the Beam's Eye View projection. ESAPI was also used to gather patient anatomical data, serving as input for Random Forest models to select the optimal plan. The Random Forest classification considered both beam insertion geometry and optimization strategy. Dosimetric data were evaluated in accordance with the Radiation Therapy Oncology Group (RTOG) 1005 protocol. RESULTS: Overall, all approaches generated high-quality plans, with approximately 94% meeting the acceptable dose criteria for organs at risk and/or target coverage as defined by RTOG guidelines. Average automated plan generation time ranged from 6 min and 37 s to 9 min and 22 s, with the mean time increasing with additional fields. The Random Forest approach did not successfully enable automatic planning strategy selection. Instead, our automated planning system allows users to choose from the tested geometry and strategy options. CONCLUSIONS: Although our attempt to correlate patient anatomical features with planning strategy using machine learning tools was unsuccessful, the resulting dosimetric outcomes proved satisfactory. Our algorithm consistently produced high-quality plans, offering significant time and efficiency advantages.

Cost Reduction in the Production of Green Dwarf Coconut Palm Seedlings Biostimulated with Bacillus cereus.

The production of coconut tree seedlings is an important step in the production process, as it substantially affects the productive performance of the adult plant, and the way of obtaining seedlings directly reflects the added costs. To minimize costs, the introduction of biostimulants can be considered a viable and sustainable technology. This study aimed to evaluate the effects of applying Bacillus cereus in promoting growth and reducing the costs of producing Brazilgreen dwarf coconut seedlings. The study has two stages, the first was an experiment carried out in a commercial nursery in the state of Pará-Brazil. The design was completely randomized, with two treatments: control with water (100% mineral fertilization) and B. cereus inoculation (50% mineral fertilization), with 10 replicates each. Biometric parameters and the quality of seedlings were evaluated. In the second stage, the production of stimulated seedlings was compared to that of commercial seedlings, and the effective operating cost (COE) and the total operating cost (TOC) were determined. Biostimulation with B. cereus promotes the growth of coconut tree seedlings, increases seedling quality, and reduces nursery time. In addition, the cost of production is reduced by 10%. Thus, microbial technology is a positive strategy for the production of Brazilian green dwarf coconut seedlings. Using B. cereus can guarantee obtaining seedlings with high performance and at a lower cost. These results may favor obtaining adult plants with high productivity. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01163-9.

Prevention of Thelazia callipaeda Reinfection among Humans.

Thelazia callipaeda is a zoonotic vector-borne nematode that infects and causes eye disease among a wide range of domestic and wild mammals, including humans. We describe an unusual case of reinfection by this nematode in Serbia and call for a focus on preventive measures in endemic areas.

Elimination of Dirofilaria immitis Infection in Dogs, Linosa Island, Italy, 2020-2022.

On Linosa Island, Italy, Dirofilaria immitis infection has been hyperendemic in dogs and seroprevalent among islanders. In 2020, we implemented a heartworm disease elimination program on Linosa Island. Of 54 dogs tested for D. immitis antigen and microfilariae, 28 had positive results and received treatment with oral doxycycline twice daily for 4 weeks plus topical imidacloprid/moxidectin monthly for 12 months. The 26 dogs with negative results received monthly topical imidacloprid/moxidectin as preventive. During month 1, the number of microfilaremic dogs was reduced by 76.5%. From month 2 on, all animals were microfilariae negative, and during months 3 to 9, the number of antigen-positive dogs decreased progressively. Treatment of positive dogs coupled with chemoprophylaxis for noninfected dogs was effective, protecting them from new infections. The elimination program reduced the risk for human infection, representing a One Health paradigm. Monitoring and chemoprophylaxis are advocated to maintain the status of heartworm disease-free area.

Pure Cut or Endocut for Biliary Sphincterotomy? A Multicenter Randomized Clinical Trial.

INTRODUCTION: Adverse events (AE) after endoscopic retrograde cholangiopancreatography (ERCP) are not uncommon and post-ERCP acute pancreatitis (PEP) is the most important one. Thermal injury from biliary sphincterotomy may play an important role and trigger PEP or bleeding. Therefore, this study evaluated the outcomes of 2 electric current modes used during biliary sphincterotomy. METHODS: From October 2019 to August 2021, consecutive patients with native papilla undergoing ERCP with biliary sphincterotomy were randomized to either the pure cut or endocut after cannulation. The primary outcome was PEP incidence. Secondary outcomes included intraprocedural and delayed bleeding, infection, and perforation. RESULTS: A total of 550 patients were randomized (272 pure cut and 278 endocut). The overall PEP rate was 4.0% and significantly higher in the endocut group (5.8% vs 2.2%, P = 0.034). Univariate analysis revealed >5 attempts ( P = 0.004) and endocut mode ( P = 0.034) as risk factors for PEP. Multivariate analysis revealed >5 attempts ( P = 0.005) and a trend for endocut mode as risk factors for PEP ( P = 0.052). Intraprocedural bleeding occurred more often with pure cut ( P = 0.018), but all cases were controlled endoscopically during the ERCP. Delayed bleeding was more frequent with endocut ( P = 0.047). There was no difference in perforation ( P = 1.0) or infection ( P = 0.4999) between the groups. DISCUSSION: Endocut mode may increase thermal injury leading to higher rates of PEP and delayed bleeding, whereas pure cut is associated with increased intraprocedural bleeding without clinical repercussion. The electric current mode is not related to perforation or infection. Further RCT assessing the impact of electric current on AE with overlapping preventive measures such as rectal nonsteroidal anti-inflammatory drugs and hyperhydration are needed. The study was submitted to the Brazilian Clinical Trials Platform ( http://www.ensaiosclinicos.gov.br ) under the registry number RBR-5d27tn.

Virulence and antimicrobial resistance genes profiles of spa type t605 methicillin-susceptible Staphylococcus aureus isolated from subclinical bovine mastitis.

AIMS: Staphylococcus aureus is one of the most common pathogens associated with mastitis in dairy herds worldwide. This study evaluated the profile of virulence and antimicrobial resistance genes of spa type t605 methicillin-susceptible Staphylococcus aureus isolated from subclinical bovine mastitis in São Paulo, Brazil. METHODS AND RESULTS: A total of 57 S. aureus strains were screened by conventional PCR (Polymerase Chain Reaction) for 49 virulence genes. The most prevalent virulence genes detected were icaD (94.7%), fib (93%), fnbA (82.5%), clfA (80.7%), bap (78.9%), clfB (73.7%), icaA (66.7%), see (64.9%), and sed (61.4%). The blaZ (94.7%), aac6'aph2' (15.8%), and ant4 (12.3%) genes were the most common antimicrobial resistance genes; however, mecA and mecC genes were not found. All methicillin-susceptible S. aureus (MSSA) strains were characterized through spa and agr typing. The spa type t605 was found in all isolates. By agr typing, the most prevalent were type II (56.1%). Antimicrobial resistance was determined by the disk diffusion method, and 93% showed resistance to at least one antibiotic. Penicillin resistance was the most prevalent (87.7%), followed by tetracycline (12.3%), oxacillin (10.5%), and gentamicin (10.5%) resistance. CONCLUSION: Our study confirmed the spa type t605 as endemic, carrying a wide variety of virulence factors and high-level penicillin resistance. The profile seems to be associated with the colonization of MSSA and its persistence in subclinical mastitis.

MALDI-TOF bacterial subtyping for rapid detection of biomarkers in Staphylococcus aureus from subclinical bovine mastitis.

AIMS: This study aimed to evaluate matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) bacterial subtyping for the rapid detection of biomarkers in Staphylococcus aureus from subclinical bovine mastitis. METHODS AND RESULTS: A total of 229 S. aureus isolates were obtained from milk samples collected from cows with subclinical mastitis using microbiological culture. Staphylococcus aureus isolates were also submitted to PCR analysis targeting the mecA and mecC genes, which are indicative of methicillin resistance. Confirmation of the species was achieved through MALDI-TOF MS analysis. To analyze antimicrobial resistance patterns, the MALDI BioTyper Compass Explorer and ClinProTools Bruker software were employed, and dendrograms were generated using Bionumerics software. CONCLUSIONS: MALDI-TOF MS successfully identified S. aureus at the species level, but no methicillin resistance was observed. Moreover, spectral typing displayed limited similarity when compared to pulsed-field gel electrophoresis (PFGE).

Temporal trends of persistent organic pollutant contamination in Franciscana dolphins from the Southwestern Atlantic.

Persistent organic pollutants (POPs) were analyzed in 136 blubber samples of Franciscana dolphins from Brazil (Pontoporia blainvillei), which is the most threatened dolphin in the Southwestern Atlantic. The dolphins were caught by the fishery fleet and collected from 2000 to 2018 in three regions of São Paulo state: northern São Paulo (SPN), central São Paulo (SPC), and southern São Paulo (SPS). The POPs analyzed in this study were polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDTs), Mirex, hexachlorobenzene (HCB), chlordane compounds (CHLs), hexachlorocyclohexane isomers (HCHs), and polybrominated diphenyl ethers (PBDEs). The concentrations ranged from 36 to 7200 ng g-1 lipid weight (lw) and 113-42200 ng g-1 lw for predominant compounds DDTs and PCBs, respectively. Similar profiles of PCB congeners were observed with a predominance of hexachlorinated compounds, representing approximately 50% of the total PCB amount; the highest PCB concentrations were observed from Baixada Santista (SPC) proximate to a highly urbanized and industrial coastal area. Significant differences were observed between the sexes and maturity of dolphins, mainly for PCBs, DDTs, and Mirex. In general, POPs other than HCB in Franciscana dolphins showed downward temporal trends, matching the regulatory periods for restricting and/or banning these compounds. Although POP concentrations are declining, PCB levels remain high in small dolphins, suggesting adverse health effects on Franciscanas. As organic contaminants are one of the numerous threats Franciscanas have been vulnerable to along the Brazilian coast, we recommend monitoring POPs levels every five years to check for declining (or stabilizing) trends.

Obtaining the spectroscopic quality factor through the luminescent thermometry in 50Li2O · 45B2O3 · 5Al2O3 glasses doped with Nd3+ and fluorides.

Lithium-boron-aluminum (LBA) glasses doped with N d 3+ and fluorides were produced. From the absorption spectra, their Judd-Ofelt intensity parameters, Ω 2,4,6, and spectroscopic quality factors were calculated. Exploiting their near infrared temperature dependent luminescence, we investigated their potential for optical thermometry based on the luminescence intensity ratio (LIR) methodology. Three LIR schemes were proposed, and relative sensitivity values up to 3.57±0.06% K -1 were obtained. From the temperature dependent luminescence, we alternatively calculated their corresponding spectroscopic quality factors. The results indicated that N d 3+-doped LBA glasses are promising systems for optical thermometry and as gain mediums for solid-state lasers.

Antimicrobial activities of polyhexamethylene biguanide against biofilm-producing Prototheca bovis causing bovine mastitis.

Prototheca spp. is a frequent cause of bovine mastitis and is highly resistant to commonly used disinfectants. This study aimed to: (1) evaluate the antimicrobial activity of polyhexamethylene biguanide (PHMB) against mastitis-causing Prototheca spp., and (2) evaluate the biofilm production ability of Prototheca spp. A total of 85 Prototheca bovis and 2 Prototheca blaschkeae isolates from bovine mastitis cases were submitted to biofilm production assays and antimicrobial susceptibility tests against PHMB and disinfectants commonly used in dairy herds (chlorhexidine digluconate, povidone-iodine, sodium dichloroisocyanurate, and sodium hypochlorite). The minimal inhibitory concentration (MIC) and minimal algicidal concentration (MAC) were determined by microdilution assays. We observed that PHMB (MIC90: ≥2 µg/mL and MAC90: ≥4 µg/mL) and chlorhexidine gluconate (MIC90 and MAC90: ≥2 µg/mL) presented the highest antimicrobial activity against P. bovis isolates, followed by sodium dichloroisocyanurate (MIC90 and MAC90: ≥1,400 µg/mL), sodium hypochlorite (MIC90 and MAC90: ≥2,800 µg/mL), and povidone-iodine (MIC90 and MAC90: ≥3,200 µg/mL). Concerning P. blaschkeae isolates, PHMB (MIC and MAC ≥1 µg/mL) and chlorhexidine gluconate (MIC and MAC ≥1 µg/mL) were the disinfectants that presented the lowest concentration values required to inhibit the isolates. Regarding biofilms formation, 63.5% (n = 54/85) of the P. bovis isolates were classified as strong, 28.3% (n = 24/85) moderate, and 8.2% (n = 7/85) weak biofilm producers. In contrast, the P. blaschkeae isolates were classified as weak and moderate biofilm producers. These findings suggest that PHMB has the potential to be used for teat and milking-equipment disinfection for the prevention of mastitis-causing Prototheca spp. in dairy herds.