Fungi are eukaryotic organisms that can function as pathogens. Diseases caused by pathogens are called infectious diseases. It states that microorganisms known as pathogens or "germs" can lead to disease. Pathogens and parasites, notably rabies, may infect wolves. Some plants and fungi act as vectors for various pathogens. Trimethoprim has shown to have activity against a variety of Gram-positive bacterial pathogens. These act synergistically against infection by pathogens. Handshakes are known to spread a number of microbial pathogens. Several classes of enveloped viruses that contain human pathogens are recognized. No clear examples of archaeal pathogens or parasites are known. Human feces contains a variety of potentially harmful human pathogens. Crickets have many natural enemies and are subject to various pathogens and parasites. This means it is especially good at fighting extracellular pathogens and fungi. Fc receptors bind to antibodies that are attached to infected cells or invading pathogens. Chemical disinfectants are products that kill pathogens.