Which of the following organisms are transmitted to animals and humans after a tick bite?

The correct choice is the one that identifies the organisms that are specifically transmitted through tick bites. Ehrlichia and Anaplasma spp. are recognized as tick-borne pathogens that infect both animals (such as dogs) and humans. These organisms are categorized as rickettsial diseases, which are transmitted by various tick species. When an infected tick bites a host, it can introduce these bacteria into the bloodstream, leading to conditions such as ehrlichiosis and anaplasmosis in humans and animals.

In contrast, the other organisms listed do not share this transmission route. Leptospira is primarily transmitted through contact with water or soil contaminated with urine from infected animals; it is not related to ticks. Chlamydia and Mycoplasma spp. are more commonly associated with different infections involving respiratory or reproductive tracts and do not rely on tick vectors for transmission. Neisseria sicca is typically part of the normal flora in humans and is not transmitted via ticks; it is more associated with opportunistic infections rather than vector-borne illnesses.

Thus, the identification of Ehrlichia and Anaplasma as tick-transmitted organisms is crucial for understanding the epidemiology of these diseases and their implications for human and animal health.