You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:

 escherichia fergusonii was described as a new species of the genus escherichia , family enterobacteriaceae in 1985 .
it is closely related to e. coli , with whom it shares many of its biochemical properties and resembles the genus salmonella in the lack of lactose breakdown activity .
when first identified , the clinical significance of this organism was unclear . first isolate suggesting that this organism was a pathogen was from a human patient with pancreatic carcinoma and cholangiosepsis , in switzerland .
the organism was detected in the blood , gallbladder fluid , feces , and a superficial abdominal wound . in the veterinary literature ,
e. fergusonii has been associated with a clinical case of acute enteritis , septicemia , and death of an adult horse from germany .
e. fergusonii was also isolated from intestine , lung , liver , and kidney from a goat with a history of chronic diarrhea and emaciation , in canada . in cattle ,
birds seem to be also susceptible to e. fergusonii infections ; this bacterium was isolated in pure growth from lesions in ostriches with severe hemorrhagic diarrhea and fibrinonecrotic typhlitis .
common pulmonary bacterial pathogens in cattle include mannheimia haemolytica , pasteurella multocida , histophilus somni , mycoplasma bovis , and trueperella ( arcanobacterium ) pyogenes .
young animals are more prone to develop pneumonias caused by one or more of these agents ; however , adult animals are also susceptible , particularly when immunocompromised . in this report ,
escherichia fergusonii was isolated in pure culture from otherwise pneumonic lesions , where one or more of the common bacterial pathogens for cattle were expected to be found .
a 4-year - old angus cow , pregnant , nursing her 6-month - old heifer , was found down , alert , tachypneic , and with hyperthermia ( 41.7c ) .
the herd had been moved to a new irrigated pasture the day before the animal was presented for clinical evaluation .
the referring veterinarian treated the cow with iv fluids , flunixin meglumine , and ceftiofur . despite treatments ,
the animal was found dead the next day and submitted for postmortem examination together with a blood sample drawn the previous day .
the case was described as acute , lasting only 36 hours ; other herdmates were not affected .
on necropsy , the animal was in fair postmortem state , good nutritional status , mildly dehydrated , and icteric . a 25  cm .
the cecum had a dark brown runny content , and the spiral colon had dry brown feces .
the packed cell volume was determined in the submitted blood sample and found to be 26% .
sections of lung , liver , spleen , kidney , heart , rumen , abomasum , small , intestine , spiral colon , mammary gland , and brain were fixed in 10% buffered formalin , routinely processed for histology and examined .
it consisted of a fibrinonecrotic bronchopneumonia with large , irregular , necrotic alveolar areas , filled with fibrin and surrounded by densely packed neutrophilic infiltrates , including oat cells , suggestive of mannheimia spp . or pasteurella spp . infection ( figure 1 ) . within the necrotic areas ,
the liver displayed centrilobular hepatocellular degeneration , with incipient hepatocyte necrosis ( suggestive of hypoxic changes ) , mild histiocytic infiltration in sinusoids , and increased bile in canaliculi .
the mammary gland had a chronic - active suppurative mastitis with increased interlobular fibrosis , multifocal acinar necrosis , neutrophilic exudates into the acinar and ductal lumina , and moderate numbers of intralesional gram - negative coccobacilli .
rare intraerythrocytic parasites consistent with anaplasma sp . were detected with wolbach - giemsa staining in the liver and lungs and in a smear from the fresh blood sample stained with diff - quick ( in > 1% of rbc , estimated ) .
lungs and liver were cultured on blood - agar and macconkey - agar plates , incubated for 48 hours , 37c in aerobic , co2 enriched conditions ( 7% co2 ) .
culture identification was performed with standard biochemical procedures and confirmed with commercial enteric identification system ( api 20 e test by biomerieux ) . the single bacterial isolate in pure culture and in large numbers from two lungs and one liver samples
was acid / acid ( a / a ) , gas producer , and h2s negative on triple sugar iron media ( tsi ) , motile , indole , and ornithine decarboxylation positive on motility - indole - ornithine media ( mio ) , orthonitrophenyl--galactoside ( onpg ) positive , urea hydrolysis positive and negative for citrate utilization . based on these findings isolate was identified as escherichia fergusonii . given the unusual bacteriological results and lung histology suggestive of another , rather than escherichia spp .
e. fergusonii was isolated again from lung , in pure culture and large numbers . on kirby - bauer disk diffusion test , using interpretation criteria as with e. coli , the isolate was resistant to ceftiofur , erythromycin , penicillin , and ampicillin , and it was sensitive to neomycin , streptomycin , tetracycline , and florfenicol . 

anaplasma infection was confirmed by pcr , test performed on splenic tissue at the washington animal disease diagnostic laboratory as previously described .
leptospira was ruled out by fluorescence antibody test ( fat ) on kidney smears ( leptospira fluorescent antibody conjugate , national veterinary services laboratory ) .
range 0.250.5  ppm ) , copper , zinc , and iron were within normal limits and mercury , and arsenic , cadmium , and lead were not detected .

 e. fergusonii pathogenic capability has been demonstrated as reported in multiple species including humans , several mammalians , and birds [ 26 ] . here
, e. fergusonii appears to be responsible for a severe , acute pneumonia and death in an adult cow .
it is possible that stressors such as an anaplasma infection with mild anemia , low selenium levels , and advanced pregnancy while nursing a 6-month - old calf may have contributed to an immunocompromised animal susceptible to this bacterium .
while the lesions were histologically suggestive of mannheimia / pasteurella pneumonia ( oat cells formation ) and assuming e. fergusonii would produce escherichia coli - like lesions ( suppurative rather than fibrinonecrotic ) , recovering e. fergusonii in large numbers and pure culture from 3 lung sampling sites ( 2 on necropsy and 1 reculture ) would suggest that this pneumonia was due to the bacterium .
it is possible that mannheimia / pasteurella started the pneumonic process , induced the lesions associated with these bacteria , and then were controlled with antimicrobial treatment . under this condition , if e. fergusonii was present it was then able to multiply and appear as the agent responsible for the proceeding severe , acute pneumonia leading to death .
it is highly unusual for a single dose of an antimicrobial product to clear a pathogen such as mannheimia / pasteurella when death occurs soon ( less than 24 hours ) after the initiation of treatment .
if this scenario happened , e. fergusonii should still be considered an opportunistic but potentially a severe pulmonary pathogen for cattle .
postmortem contamination was considered but if e. fergusonii was a relatively common contaminant , it would be frequently detected in animals submitted for necropsy with some autolysis and often in mixed cultures .
e. fergusonii is rarely isolated from necropsy samples in our bacteriology laboratory , never in large numbers and pure culture .
isolation from liver is suggestive of a potential bacteremic spread when disease was advanced or terminal .
we believe that e. fergusonii is an organism that under certain circumstances might act as a lung pathogen in cattle . to our knowledge , this is the first case where e. fergusonii is reported as a pulmonary pathogen in cattle .
an adult angus cow developed hyperthermia , prostration , and respiratory distress , dying 36 hours after the onset of clinical signs . 
 the main finding during postmortem examination was a severe focally extensive pneumonia . 
 icterus and a chronic mastitis were also noticed . 
 histologic examination of the lungs detected fibrinonecrotic pneumonia , with large number of oat cells and intralesional gram - negative bacterial colonies . 
 samples from lung lesions were collected , and a pure growth of escherichia fergusonii was obtained . 
 e. fergusonii is a member of enterobacteriaceae , related to escherichia coli and salmonella sp . in veterinary medicine , 
 e. fergusonii has been reported in calves and sheep with clinical cases suggestive of salmonellosis ; in a horse and a goat with enteritis and septicemia ; and in ostriches with fibrinonecrotic typhlitis . to our knowledge 
 , this report represents the first description of e. fergusonii associated with an acute pneumonia in cattle .