Individuals considered at greatest risk for contracting brucellosis are: dairy farmers. Facultative, intracellular parasitic bacteria are those that are able to: in both intracellular and extracellular environments Organisms belonging to the genus Brucella are: gram-negative coccobacilli Although in vitro susceptibility testing is not reliable, which regimen of antibiotics is recommended for Brucella infections? Doxycycline and rifampin The animal reservoir for Brucella melitensis is: sheep or goats Pertussis (whooping cough) is an epidemic disease that is a highly contagious, acute infection of the upper respiratory tract caused by the Bordetella spp The mode of transmission of Bordetella pertussis can best be described as person-to-person contact During the catarrhal stage of pertussis, symptoms are nose and mild cough During the paroxysmal stage of pertussis, symptoms are severe and violent coughing Acceptable specimens for the detection of Bordetella pertussis are nasopharyngeal aspirates Because of its longer shelf life, the medium of choice to cultivate Bordetella spp. is Regan-Lowe agar Which of the following toxins contributes to the virulence of Bordetella pertussis and works by hemolyzing red cells and activating cyclic adenosine monophosphate, which inactivates several types of host immune cells? Adenylate cyclase toxin Bordetella pertussis colonies growing on Regan-Lowe medium yields which of the following colonial morphologic appearances? Mercury-drop colonies A nasopharyngeal aspirate is cultured on Bordet-Gengou agar, and growth is observed. The colonies are also subjected to a direct fluorescent antibody (DFA) stain, which is also positive. On the basis of these findings, the antimicrobial therapy that should be administered to the patient is Azithromycin
kill organisms such as Toxoplasma and Sarcocystis. The polar tubule, which is responsible for the entrance of infective sporoplasm into the host cell, is found in which genera? Enterocytozoon In cases of malaria, the primary exoerythrocytic cycle occurs in the? liver Delicate ring and crescent-shaped gametocytes are the only forms normally observed in the peripheral blood of which Plasmodium spp.? P. falciparum A ring, large nucleus, and bands across the cell and 6 to 12 merozoites in a mature schizont are all characteristics of which Plasmodium spp.? P. malariae Cerebral malaria is considered to be the most serious complication and major cause of death with which species of Plasmodium spp.? P. falciparum Plasmodium vivax is suspected in a patient who has been traveling for months in the tropics. Blood was collected in a lavender top tube; however, the slide was not prepared for examination until the next day because the specimen came in on the night shift. Once the slide was prepared and examined, Schüffner dots were not visible. Which one of the following statements explains this discrepancy? The blood remained in the tube too long, yielding false-negative results. Resistance to chloroquine and mefloquine has been identified in which Plasmodium spp.? P. falciparum Ring forms and a “Maltese cross” were observed in a blood smear. The vector that transmits this disease is a(n)? tick. Chagas disease is caused by? T. cruzi. The vector Glossina palpalis group transmits the Trypanosoma brucei gambiense organism. The diagnostic stage is the? trypomastigote. Stage I of trypanosomiasis characteristically involves systemic trypanosomiasis infection without central T. brucei gambiense
Systemic involvement is rare in infection caused by Ancylostoma braziliense or A. caninum; however, pneumonitis may occur. The antihelminthic therapy used to treat this infection is ivermectin or thiabendazole What is the mode of transmission for Dracunculus medinensis? Copepods What is the mode of transmission for Parastrongylus cantonensis? Crabs What is the mode of transmission for Trichinella spp.? Pigs What is the mode of transmission for Parastrongylus costaricensis? Snails The definitive host and reservoir for Wuchereria bancrofti is: Humans Chyluria is a result of lymphatic rupture and fluid entering the urine. Another lymphatic condition caused by Wuchereria bancrofti is: Elephantiasis. A 36-year-old man who has been traveling through the orient is experiencing a tender region in the inguinal region. A blood film is made, and sheathed microfilariae with four to five subterminal nuclei and two terminal nuclei in the tail are identified using Giemsa stain. The organism is most likely: Brugia malayi A skin snip is performed, and microfilariae with tapered tails, no nuclei, and unsheathed are microscopically observed. The recommended therapy for this infection is: Ivermectin. A Giemsa stain is performed on an eye exudate on a patient with calabar swelling, eosinophilia, and a recent travel history to Africa. Loa loa is suspected; however, the sheath in the adult worm recovered does not stain. Which one of the following statements explains this discrepancy? No discrepancy is present. The sheath does not stain with Giemsa stain. Which organism is transmitted by Tabanid fly? Loa loa Which organism is transmitted by Biting midges? Mansonella spp Which organism is transmitted by Anopheles mosquito? Brugia spp. Which organism is transmitted by Black fly? Onchocerca