Thursday, June 23, 2011

Epidemics of Diarrhea due to Escherichia coli (Shiga toxin producing enterohemorrhagic) in Europe

Recently, enterohemorrhagic Escherichia coli (EHEC) strain has infected over 3,500 and kills over 40 people in the Europe and most of them are German [1]. Initially, it was blamed to salad and vegetables and the farmers for the cause of transmission, as concluded by case-control study. But the causative bacterial strain, EHEC O104:H4 has not been found in any of these salad and vegetables samples. Then authorities realize farmers were not culpable. Then they withdraw the blame with apology and announce the compensation for farmers. Now suspecting on bean, sprout, and agricultural practice [2].

EHEC O104:H4 is a type of E. coli classified on the basis of somatic O-antigen (over 170 different type: 1-170), and flagellar H-antigen (over 50 different types: 1-50). In E. coli, there are different chemical structure and functional group comprising lipopolysaccharide of plasma membrane (O-antigen), polysaccharide of  capsule (K-antigen) and flagella (H-antigen). Combining of these different antigens there could be thousands of different types of E. coli. The infective EHEC O104:H4 is new to Europe but this strain was reported from Korea in 2006 [3]. Does this means this strain is shipped from Korea? Certainly not, or needs exigent research.

Every organism has the tendency to adapt the environment with necessary genotype reshuffle or addition, and phenotypic variation, suitable to survive, as Darwinism. Bacterial strains also, always tend to increase virulence and pathogenicity by adapted gene transfer and mutation. In latent type of infection, plasmid and/or gene transferred from virulent strain to non-virulent may get proliferated for several months without symptom and unknown to health professional. This may be the one of the possible reason for outbreak in Europe, which is still under research to find the source of infection. So, the organism whose reservoir is the environment, they proliferated when the environmental condition becomes optimum, as said by Rita Colwell [6].

Vibrio, Escherichia has the environmental reservoir unlike smallpox and polio virus. So they are always prone to infect mammal once environmental condition become favourable. E. coli is even more dangerous as it is opportunistic pathogen and can acquire antibiotic resistance as well as virulence.

In my study (in NAST), some strains of E. coli were found to be resistant against all commonly used antibiotics (courtesy: Nabaraj Dahal, Pankaj Baral, and Sanjiv Neupane). This shows it is the dreadful strain having most flexibility in genetic variation among bacterial kingdom. However, the innovation and more research on antibiotics may enervates its massive proliferation.
Multi-drug resistant E. coli reconfirmed on M-endo agar.
Antibiotics sensitive E. coli (ATCC 25922) reconfirmed on M-endo agar.
Even in the Europe, the bacterial strain can invade people where living standard is high as well as good sanitation, well managed health system. Also, Nepal had faced problem of diarrhoeal epidemics and hundreds of people died in remote area, two years ago. But it was different scenario, poor people were lack of medicine and ORS.
Few months ago, an unprecedented outbreak of cholera in Haiti was the reason to blame Nepalese peacekeeping soldier. But neither stool nor rectal swab nor antibody test of these soldiers showed positive result of V. cholera (or was not investigated). Even no one could be verified as carrier. And probably, the sample of drinking water, seawater and sewage from different source was not analysed properly to make a conclusion. Only the co-incidence was the bacterial strain found there resembled with the South Asian strain, which is not only confined in Nepal but also other South Asian countries like Bangladesh, India, Pakistan etc.

  1. European Centre for Disease Prevention and Control,  Stockholm, Sweden, 22 June 2011, 11:00
  2. Editorials, 16 June, 2011, Nature, Vol. 474, 251
  3. Woo Kyun Bae, et al., Jun 2006, Yonsei Medical Journal, Vol. 47(3), 437-439
  4. Marian Turner,  9 June, 2011, Nature, Vol. 474, 137
  5. Kai Kupferschmidt, 10 June 2011, Science, Vol. 332, 1249-1250
  6. Martin Enserink, 5 November 2010, Science, Vol. 330, 738-739

Wednesday, June 15, 2011

भानुभक्त आचार्यको पादुका दान अब नयाँँ संस्करणमा

(नेपाली, साहित्य, दशक अगाडिको पानाबाट)

तहाँ सीतारामका चरणतलमा शिर पनि धरी
अयोध्यै लैजान्छु भनिकन ठूलो मनसुब गरी


तहाँ साथी भाइका चरणतलमा घरि-घरि परी
भरत बिन्ती गर्छ एउटी ठिटी मिलाइदेउ भनी

चुरोटको धुवाँमा होस् या क्यान्टिनको चनामा
उसलाई नै सोच्छ यो भरत आफ्नो मनमा

बियरको बोतल होस् या ल्याबको फ्लास्क
फुटायो कती हो कती अनी छोड्यो क्लास

भ्यागुतो होस् या गड्यौला चिर्दा या लोखर्के
खाली उस्तिर नै आँखा लगाउछँ कर्के-कर्के

क्लासको होस् या प्र्याक्टिकलको कापी सार्दा
उसलाईनै सम्झन्छ ब्याड्मिन्टन पनि हार्दा

मिररको होस् या लेन्सको प्र्याक्टिकलमा
तेर्स्याउँछ ति खाली उसकै अनुहारमा

झिम्क्याउन सिक्ने भनी माइक्रोस्कोप हेर्छ
छोडिदे त्यस्लाई भन्दा हामीलाई कहाँँ टेर्छ

ब्रश नगरेका गन्हाउने ति पहेँला दाँत पनि
भन्ने गर्छ ति सुनका दाँत किन हो कुन्नी

हामीलाई धम्क्याउछ उसलाई नपाए पनि
बिकरको एसिड पनि पिईदिन्छु भनी

साथीभाइ सम्झाउँछन नरो अरु पनि पाईन्छ भनी
उ रुन्छ सिनेमाको पैसा फिर्ता अहिल्यै चाहिन्छ भनी

(दशक पछी थपिंदा....)
एक किलो पाउडर अनी लाली दल्ने त्यो काली
कसरी पर्न गइछे त्यो मोरी त मेरो आफ्नै साली

Tuesday, June 07, 2011

Vying for Identity in Science

Update: Voting period extended upto 11th Jun, 2011

One of my article of this blog (Cholera in Haiti and Association to South Asia....) has been selected for "3QD (3QuarksDaily)" prize for non-professional science writing, which can be found here, and second round of selection depends upon voting and voting ends on June 8, 2011. However, it may not have good quality for worldwide competition. Also, this blog (Science Disdained Nepal) is listed on the blog of famous science journal; Nature, and can be found here (ScienceNepal).

Although suffering due to my poor English, internet access, and availability full text of the journals, this small achievement has encouraged me to continue on science writing and blogging.