Gram-negative infections include those caused by Klebsiella, Acinetobacter, Pseudomonas aeruginosa, and E. coli., as well as many other less common bacteria.

The appearance of Gram positive cocci in clusters on direct Gram stain is suggestive of staphylococcus species, but differentiation of Staphylococcus aureus from coagulase negative staphylococci can usually only be made 18–24 hours later, once the organism has been cultured on solid media.

Staphylococci are gram-positive aerobic organisms. Staphylococcus aureus is the most pathogenic; it typically causes skin infections and sometimes pneumonia, endocarditis, and osteomyelitis. It commonly leads to abscess formation.

Staphylococcus aureus is a gram-positive, catalase-positive, coagulase-positive cocci in clusters. S. aureus can cause inflammatory diseases, including skin infections, pneumonia, endocarditis, septic arthritis, osteomyelitis, and abscesses.

Gram-positive bacteria lack this important layer, which makes Gram-negative bacteria more resistant to antibiotics than Gram-positive ones [5,6,7]. Gram-negative bacteria can cause serious diseases in humans, especially in immuno-compromised individuals.

Salmonella illness can be serious and is more dangerous for certain people. Symptoms of infection usually appear 6 hours to 6 days after eating a contaminated food. These symptoms include diarrhea, fever, and stomach cramps. In most cases, illness lasts 4–7 days and people recover without antibiotic treatment.

The Centers for Disease Control estimates that 1 in every 20,000 eggs are contaminated with Salmonella.

Symptoms of a salmonella infection usually include diarrhea, fever, abdominal cramps, chills, headache, nausea, or vomiting.