The product of h. influenzae and pertussis thibaut also has certain antibacterial activity, other gram-negative aerobic and facultative anaerobic bacteria to this poor sensitivity. The product of clostridium, streptococcus, anaerobic bacteria and produce melanin bacteroides good antibacterial effect, the antibacterial effect of bacteroides fragilis. Penicillin has a bactericidal effect by inhibiting the binding of bacterial cell wall tetrapeptide chain and pentapeptide cross - bridge and impeding cell wall synthesis. It is effective for gram-positive bacteria, but penicillin has little effect on gram-negative bacteria due to the lack of pentapeptide cross-linking bridge.

Qingdao Sigma Chemical Co.,Ltd is a global chemical industry manufacturers and suppliers of pharmaceuticals 

and intermediates, food and feed additives, herbal extracts, agrochemicals and fine chemicals etc.

The aim of Qingdao Sigma Chemical Co.,Ltd is a quality policy that "Elements in the system 

all have been satisfied, Personnel has been trained; Every batch of material is checked, Each procedure guarantees the quality; Every bag of our products is top grade, Service is thoughtful all the time, quality and reputation to increase market share and promote enterprise development. The quality, colors and forms of our products have reached a high level in related chemical industry, which relies on characteristic and advanced processing technology and it has gained a high and reliable reputation from customers at both quality and services.