The bacterial species,<u> Listeria monocytogenes</u>, accounts for 12%-15% of infant meningitis cases.
Explanation:
Listeria monocytogenes is a group B strep gram-negative bacteria, one of the main causes of meningitis.
This species is psychrotrophic in nature which means that it can grow at low temperatures like refrigerator temperature and mostly found in areas with a temperature around 15-20 degrees Celsius.
These organisms also become psychrotolerant or psychrophiles and can grow at places where the temperature fluctuates.
This is the main reason for the spoilage of food stored in a refrigerator. So leftover baby foods, bottles stored in a refrigerator can be contaminated with these species.
When the infants ingest the contaminated food or use the bottle, they also get infected. Listeria monocytogenes cause meningitis in infants especially who are immunocompromised infants.
Answer:
The principal difference in development of Dorsoventral axis in deuterostomes and protostomes is something called inversion
Explanation:
In protostomates the neural tube is below the gut and the dorsal vessel is above the gut while in deuterostomates is the oppossite, there is an inversion and now, the neural tube is above the gut and the heart tube is below. In both cases the development is related to the gradient of expression of some genes, where the expresion of one gene supress the formation of one structure in one side of the axis.
In protostomates the TGT-B factor is expressed dorsally and supress neural tube formation and ventrally a sog gene is expressed and supress TGT-F factor allowing neural tube to develop. In deuterostomates, an homolog of TGT-B family gene BMP-4 is expressed ventrally while dorsally BMP inhibitors (sog gene like) are expressed.
Accordingly to some researchers, the first state of the common ancestor of deuterostomates and protostomates had an protostomate-like orientation in dorsoventral axis
