Staphylococcus spp. are among the main pathogens responsible for important infections worldwide, both in humans and in domestic or wild animals. Chiropterans, popularly known as bats, inhabit natural environments and human constructions, and have been considered potential disseminators of several pathogens. Studies have shown the expression of the mecA gene in these animals, being a significant threat to One Health. The objective of this study was to determine antibiotic resistance and the presence of the mecA gene in Staphylococcus spp. isolates from bats from forest areas in the municipalities of Paraná, Brazil. A total of 87 frugivorous chiropterans belonging to the family Phyllostomidae were captured. Of these, 87 rectal and 87 oral swabs samples were collected, re-sulting in 32 Staphylococcus spp. isolates. Twenty-four isolates were characterized as coagu-lase-negative, and 8 coagulase-positive Staphylococcus spp. (STACP), which showed notable re-sistance to oxacillin (78.12%), penicillin G (65.62%) and to other antimicrobials as well. One STACP isolate was mecA-positive. Therefore, further studies are needed to elucidate the mechanisms of contamination and dissemination of these pathogens, emphasizing that anthropic actions in na-tural environments, especially those related to the use of antimicrobials, pesticides may be the main reasons for the presence of resistant bacteria in bats.

Leishmania infantum is a parasite that causes leishmaniasis in its visceral clinical manifestations, which is considered a zoonosis and can infect both humans and animals. Currently, there is no highly effective treatment available, and many animals that exhibit symptoms ultimately die as a result of the disease and its complications. The clinical signs of leishmaniasis are varied and nonspecific. The main symptoms are severe anemia and thrombocytopenia, weight loss, splenomegaly, lymphadenomegaly, liver disease, kidney failure, and skin lesions, among others. Due to the chronic inflammatory state caused by the parasite, an oxidative environment is created, leading to potential cell injury and damage to the infected animals’ genetic material. To investigate DNA damage, we conducted the micronucleus test and comet assay, as well as measured serum LDH levels in infected and non-infected dogs. Our results indicate that infected dogs present significantly higher levels of serum LDH (461.4 ± 204.5 U/L, n=36) compared to healthy dogs (142.38 ± 37.94 U/L, n=5). Additionally, the DNA of infected dogs is more damaged than that of the control group, as demonstrated by the micronucleus test (p=0.01) and comet assay (p=0.002). These findings suggest that Leishmania infantum infection can lead to clastogenic events, highlighting the need for further research on this process. It is important to consider the potential mutagenic properties of Leishmania infantum, given its ability to cause DNA damage in infected animals. Leishmania infantum é um parasita que causa leishmaniose em sua forma clínica visceral, considerada uma zoonose que pode infectar tanto humanos quanto animais. Atualmente, não há um tratamento altamente eficaz disponível, e muitos animais que apresentam sintomas acabam morrendo em decorrência da doença e de suas complicações. Os sinais clínicos da leishmaniose são variados e inespecíficos. Os principais sintomas incluem anemia grave e trombocitopenia, perda de peso, esplenomegalia, linfadenomegalia, alterações hepáticas, insuficiência renal e lesões cutâneas, entre outros. Devido ao estado inflamatório crônico causado pelo parasita, cria-se um ambiente oxidativo que pode levar a lesões celulares e danos ao material genético dos animais infectados. Para investigar o dano ao DNA, realizamos o teste do micronúcleo e o ensaio cometa, além da medição dos níveis séricos de LDH em cães infectados e não infectados. Nossos resultados indicam que cães infectados apresentam níveis significativamente mais altos de LDH sérico (461,4 ± 204,5 U/L, n=36) em comparação com cães saudáveis (142,38 ± 37,94 U/L, n=5). Além disso, o DNA dos cães infectados apresenta mais danos do que o do grupo controle, conforme demonstrado pelo teste do micronúcleo (p=0,01) e pelo ensaio cometa (p=0,002). Esses achados sugerem que a infecção por Leishmania infantum pode levar a eventos clastogênicos, ressaltando a necessidade de mais pesquisas sobre esse processo. É importante considerar as potenciais propriedades mutagênicas de Leishmania infantum, dada sua capacidade de causar danos ao DNA em animais infectados.