Question

A homeless, 59- year-old man, Hugh Grant (just for the purposes of the case study), presented to the emergency room complaining of fever and chills of 4 days’ duration, with dizziness over the last 24 hours. He also complained of intermittent diarrhea and constipation over the past 6 months with occasional bloody stool. He told the physician that he ate what he could due to his circumstances. The patient’s breathing was rapid, but his lung sounds were clear. His temperature was 103^oF. Hugh was hypotensive, tachycardic, and had an appreciable heart murmur. Blood was drawn for a complete blood count (CBC) and culture. A stool specimen was collected to test for occult blood, and a chest x-ray was performed. Results of the laboratory tests are shown in Table 1A and in the list following the chart.

Table 1A: Hematology Results

	Complete Blood Count
	Hugh G.	Reference Range
WBC	9.1	5-10 x 109/L
RBC	4	5-6 x 1012/L
Hb	122	135-175 g/L
Hct	0.4	.41-.53 L/L
MCV	100	80-100 fL
MCH	32	26-34 pg
MCHC	30	31-37 g/dL
RDW	15.6	11.0-14.5
Platelets	458	150-400 x 109/L
MPV	7.2 fL	6.5-12.0 fL
RBC morphology	2+ microcytosis
	1+ macrocytosis
	1+ ovalocytosis
	1+ basophilic stippling
	2+ hypochromia
	1+ polychromatophilia
	2+ toxic granulation
	Rare Döhle bodies
	Rare hypersegmentation
	2 nucleated RBCs
Differential
Polymorphonuclear neutrophils	52	25-60%
Bands	10	0-10%
Lymphocytes	35	20-50%
Monocytes	1	2-11%
Metamyelocytes	2	0%

The stool was positive for occult blood.

All blood cultures were positive within 24 hours.

Gram’s stains from the bottles revealed gram-positive cocci in chains.

Subcultures grew readily on BAP and produced small gray gamma-hemolytic colonies.

Additional biochemical testing yielded the following:

• catalase: negative
• bile esculine agar: growth with black precipitate
• growth in 6.5% NaCl: negative
• L-Pyrrolidonyl ß-naphthylamide PYR test: negative.

Questions

1. what would be the appropriate timing and number for the collection of routine blood cultures for this patient?
2. Contamination in blood cultures can be a problem. What step(s) should be followed to keep contamination rate low?
3. What criteria might be used to determine if a positive blood culture is due to contamination or bacteremia?
4. Does Hugh have bacteremia? Does Hugh have septicemia? What is the difference between the bacteremia and septicemia?
5. Given the Gram’s stain reaction and morphology of the bacteria, what might be some possibilities for the identity of the organism
6. Given Hugh’s history, physical findings, other clinical data, and the further biochemical testing that was performed on this isolate, what is the likely identification of this organism?
7. If latex agglutination testing was performed, to which group would this organism belong?
8. What other testing methods might be employed to get a definitive identification of this organism by genus and species?
9. Hugh has a complex medical history and presentation.
   1. Describe his blood picture results in correct hematological terms?
   2. Give an explanation for toxic granulation.
   3. Give 2 reasons for macrocytes and ovalocytes
   4. Give reason for microcytes
   5. What other tests might be indicated for his occult blood results?

Answer 1

a.

• WBC level is normal
• RBC level is decreased : Anemia is condition that happens when red blood cell count is low. most scientists believe that aplastic anemia happens when the immune system attacks the bone marrow stem cells
• MCHC level is less. Alow mean corpuscular hemoglobin concentration shows that red blood cell do not have enough hemoglobin.
• RDW (Red cell distribution width) value is little high so it indicate of a nutrient defiency, such as a defiency of iron folate, or vitamin B-12 . these results could also inicate macrocytic anemia
• platelets value is increaesed. it indicate essential thrombocythemia
• monocyte value is less it indicate monocytopenia

b. Toxic granulation : It is the term used to describe an increase in staining density and possibly number of granules that occurs regularly with bacterial infection and often with other causes of inflammation

Cause of toxic granulation: is seen in cases of severe infection, as a result of denatured proteins in rheumatoid aarthitis or, less frequency, as a result of autophagocytosis. infection is the most frequent cause of toxic granulation. this phenomenon may be seen in cell whch also contain dohle bodies and vacuoles

Toxic granulation in blld work: Along with dohle bodies and toxic vacuolation, which are two other findings in the cytoplasm of granulocytes, toxic granulation is a peripheral blood film findings suggestive of an inflammatory process. toxic granulation is often found in patients with bacterial infection and sepsis, although the finding is nonspecific

• Toxic granulation is manifested by the presence of large granules in the cytoplasm of segmented and band neutrophils in the peripheral blood
• The color these granules can range from dark purplish blue to an almost red appearence
• Toxic granules are actually azurophilic granules, normally present in early myeloid forms, but are not normally seen at the band and segmented stages of neutrophil maturation. these granules contain peroxidases and hydrolases
• Toxic granulation is seen in cases of severe infection, as a result of denatured protins in rheumatoid arthritis or less frequently , as a result of autophagocytosis
• Infection is the most frrquent cause of toxic granulation cell containing only a few specific granules, with or without toxic granules, are said to be degranulated. the nucleus in degranulated cells may often be round bilobed smooth and pyknoti. this type of neucleus is the result of aging and will disintegrate soon. incrased basophilia of azurophilic granules simulating toxic granules may occur in normal cells with stain.
• The blue arrow in the image points to a neutrophil with toxic granulation. Dohle bodies are also present in the cell , indicated by the red arrows

c. The reason for macrocytes : bone marrow dysplasis secondary to alcohol abuse and chronic alcoholism, poor absorption of vitamin B12 in the diagestive tract can also cause .

The reason for ovalocytes : Ovalocytes is also called as elliptocytosis is caused by a genetic change or disease that affects the red bolld cell wall and causes the formation of many ovalocytes and also some medical condition such as anemia, liver disease, alcoholism or an inheritted blood disorder

d. The reason for microcytes: lead toxicity, chronic disease, thalassemia and hemoglobin E disorder. Iron deficiency is the most common reason of microcytes

e. over all test indicate that the patient having sever infection caused by gram positive cocci bacterias which includes staphylococcus, streptococcus