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a) phot of worms filling the intestines. B) photo of a large handful of worms. C) photo of a circle in a thicker circle. The outer circle is about 60 micrometers.
(a) Adult Ascaris lumbricoides roundworms can cause intestinal blockage. (b) This mass of A. lumbricoides worms was excreted by a child. (c) A micrograph of a fertilized egg of A. lumbricoides. Fertilized eggs can be distinguished from unfertilized eggs because they are round rather than elongated and have a thicker cell wall. (credit a: modification of work by South African Medical Research Council; credit b: modification of work by James Gathany, Centers for Disease Control and Prevention; credit c: modification of work by Centers for Disease Control and Prevention)
  • Describe the route by which A. lumbricoides reaches the host’s intestines as an adult worm.

Hookworm

Two species of nematode worms are associated with hookworm infection . Both species are found in the Americas, Africa, and Asia. Necator americanus is found predominantly in the United States and Australia. Another species, Ancylostoma doudenale , is found in southern Europe, North Africa, the Middle East, and Asia.

The eggs of these species develop into larvae in soil contaminated by dog or cat feces. These larvae can penetrate the skin. After traveling through the venous circulation, they reach the lungs. When they are coughed up, they are then swallowed and can enter the intestine and develop into mature adults. At this stage, they attach to the wall of the intestine, where they feed on blood and can potentially cause anemia. Signs and symptoms include cough, an itchy rash, loss of appetite, abdominal pain, and diarrhea. In children, hookworms can affect physical and cognitive growth.

Some hookworm species, such as Ancylostoma braziliense that is commonly found in animals such as cats and dogs, can penetrate human skin and migrate, causing cutaneous larva migrans , a skin disease caused by the larvae of hookworms. As they move across the skin, in the subcutaneous tissue, pruritic tracks appear ( [link] ).

The infection is diagnosed using microscopic examination of the stool, allowing for observation of eggs in the feces. Medications such as albendazole , mebendazole , and pyrantel pamoate are used as needed to treat systemic infection. In addition to systemic medication for symptoms associated with cutaneous larva migrans, topical thiabendazole is applied to the affected areas.

a) photo of a cler worm attached to tissue. B) photo of red lines in the skin. c) Micrograph of an oval structure.
(a) This animal hookworm, Ancylostoma caninum , is attached to the intestinal wall. (b) The tracks of hookworms are visible in this individual with cutaneous larva migrans. (c) This micrograph shows the microscopic egg of a hookworm. (credit a, c: modification of work by Centers for Disease Control and Prevention)

Strongyloidiasis

Strongyloidiasis is generally caused by Strongyloides stercoralis , a soil-transmitted helminth with both free-living and parasitic forms. In the parasitic form, the larvae of these nematodes generally penetrate the body through the skin, especially through bare feet, although transmission through organ transplantation or at facilities like day-care centers can also occur. When excreted in the stool, larvae can become free-living adults rather than developing into the parasitic form. These free-living worms reproduce, laying eggs that hatch into larvae that can develop into the parasitic form. In the parasitic life cycle, infective larvae enter the skin, generally through the feet. The larvae reach the circulatory system, which allows them to travel to the alveolar spaces of the lungs. They are transported to the pharynx where, like many other helminths, the infected patient coughs them up and swallows them again so that they return to the intestine . Once they reach the intestine, females live in the epithelium and produce eggs that develop asexually, unlike the free-living forms, which use sexual reproduction. The larvae may be excreted in the stool or can reinfect the host by entering the tissue of the intestines and skin around the anus, which can lead to chronic infections.

Questions & Answers

What are antibodies?
Happy Reply
they are immune cells that are released by immune system to fight strangers like microbes
Ahmed
a blood protien produce in response to an counteracting a specific antigen
Pooja
Why salmonella typhi is harmful protozoan?
Saily Reply
because make typhoid that is considered as a food born illness
Ahmed
Name any five modes of transmission.
Happy
what are the scientific names and common names of some microbes
Rich Reply
Staphylococcus aureus - staph Streptococcus pyogenes - strep Botulism - Clostridium botulinum Rocky Mountain spotted fever - Rickettsia rickettsii Diphtheria - Corynebacterium diphtheriae Gonorrhea - Neisseria gonorrhoeae
Tammy
what are the limitations of the Koch's postulate
Naa
how a microorganism growth.
Zubair Reply
Is foetus a parasite to his or her mother? if yes and if no ho
Mashauri Reply
y
Yusri
yes
Yashkin
yes
Zubair
yes it a parasite to the mother because it feeds on the mother for survival
Beatrice
yes
Redwan
no
Elasha
definition of a parasite: an organism that lives in or on an organism of ANOTHER species (its host) and benefits by deriving nutrients at the other's expense
Elasha
no because an organism can inky be a parasite if it causes harm to its HOST. And the fetus does not cause harm to its mother under normal conditions
aliyu
yes
Naa
what is biosensor in microbiology
Raja Reply
What are biosensor
Raja
what's are biosensor
Raja
what is microbiology defination
Rinku Reply
microbiology is the study of small or manuit organisms which cannot be seen with our nacked eyes unless with the aid of the microscope
Brandina
is the study of living organisms which are not directly visible to a direct eye but can only be seen under a microscope
Ipa
ok
Ipa
microbiology is the study of living organisms of microscopic size it is also the study of micro organisms with their form structure reproduction psychology metabolism and classification
Priyanka
what are the importances of Microbiology?
Erick Reply
don't know
SINGLE
we obtained the insulin from the bacteria. and some microorganisms are decomposer in ecosystems.
Zubair
nitrogen in the air is fixed into the soil by microbes example is nitrobactor
Matilda
yes
Zubair
how a weak immune region where microorganisms attack easily?
Zubair Reply
with examples differentiate gram positive from gram negative bacteria
Mary Reply
Differentiate gram positive from gram negative
Mary
I have no idea
Zubair
hello
Kuonain
and example of gram negative is E. coli
Pooja
gram positive stain purple when subjected to gram stain whilst gram positive bacterial has thick wall composed of peptidoglycan
Matilda
ok
Zubair
what is a process of gene expression in eukaryotes ?
Nayyab Reply
pls help us with the answer
Abdussalam
spontaneous generation means
Siddhi Reply
hiii
Siddhi
Hello
eman
So, what's next 😂
eman
I have a problem with Micro
eman
I studying things and see question Some thing else
eman
Can u help me, please
eman
What i havta do
eman
firsfall when you studying understand things...
Siddhi
good afternoon dear Friends
yaya
Greeting to everyone in here.
Manka
There is a problem. I need a diagram of a virus with it functions.
Manka
structure of bacterial
Kuyiba
gghhhh
Zubair
group plz i need help in microbio
Kuonain
it really difficult fr me
Kuonain
kashur cha kah
suhail
sorry now I read in class 8th but I can help u
Zubair
Me too. It's very difficult for me
Angela
rod shape
Priyanka
helical
Priyanka
Hello
esike
spherical
Priyanka
peomorphic
Priyanka
I am ryt or not
Priyanka
hi
suhail
hello
DIPTI
Are we together pls what's the topic for the day?
esike
what is innate
Lizzy
innate means natural
Pooja
the genetic makeup of an individual
Matilda
pls i need the common names for the following parasites..ENTEROBIUS VERMICULARIS,NECATOR AMERICANUS,ASCARIES LUMBRICOIDES,TRICHURIS TRICHIURA,TRICHOMONAS VAGINALIS,GIARDIA LAMBLIA,ENTAMOEBA HISTOLYTICA,SCHISTOSOMA MANSONI,SCHISTOSOMAHEMATOBIUM,STROGYLOIDES STERCORALIS,AND TRAPANOSOMA BRUCI GAMBIENSE
timothy
ENTEROBIUS VERMICULARIS and STROGYLOIDES STERCORALIS have the same common name which is pin worm and thread worm
Chinedu
I didn't find the common names for TRICHOMONAS VAGINALIS, GIARDIA LAMBLIA, ENTAMOEBA HISTOLYTICA, TRYPANOSOMA BRUCEI GAMBIENSE
Chinedu
NECATOR AMERICANUS - New world hookworm ASCARIS LUMBRICOIDES- Ascarid TRICHURIS TRICHIURA- Whip worm
Chinedu
Hi guys
Chinedu
Why are myeloblasts not present in the bloodstream?
Chinedu
thank u
Dasaah
is blood from capillary puncture suitable for hormonal assays
NANCY Reply
Direct this question to a hematologist for a better answer please.
LAFIA
In most cases the blood is necessary but it's limited from my own Analysis
Lee
u can do but it depends on your sampling blood its enev or not
Ali
Control indications of cipro, doxicyclin, setracyclin, cloxacyclin, erythromycin
Oslen Reply
oo
babinthe
what is sims position
babinthe Reply

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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