Which group of bacteria typically contains most of the pathogenic bacteria?

The group of bacteria that typically contains most of the pathogenic bacteria is mesophilic bacteria. This group thrives at moderate temperatures, generally between 20°C to 45°C (68°F to 113°F), which aligns closely with human body temperature (approximately 37°C or 98.6°F). It is within this temperature range that many pathogenic bacteria, including common foodborne pathogens such as Salmonella, Escherichia coli, and Listeria monocytogenes, proliferate most effectively.

Since many of these pathogenic microorganisms are adapted to grow in environments similar to the human body, they pose significant risks for human health, particularly in food safety and during outbreaks of infectious diseases. Understanding the characteristics of mesophilic bacteria is crucial for environmental health specialists or sanitarians when assessing food safety, implementing effective sanitation practices, and preventing the spread of foodborne illnesses.

Other groups, such as thermophilic and thermoduric bacteria, are less commonly associated with causing human infections, as they prefer higher temperatures or can withstand higher temperatures but are not typically pathogenic to humans.