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|Year : 2013 | Volume
| Issue : 4 | Page : 424--426
Department of Microbiology, Bhopal Memorial Hospital and Research Center, Raisen Bypass Road, Karnod, Bhopal, Madhya Pradesh, India
Department of Microbiology, Bhopal Memorial Hospital and Research Center, Raisen Bypass Road, Karnod, Bhopal, Madhya Pradesh
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Desikan P. Resaerch snippets.Indian J Med Microbiol 2013;31:424-426
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Desikan P. Resaerch snippets. Indian J Med Microbiol [serial online] 2013 [cited 2020 Jul 13 ];31:424-426
Available from: http://www.ijmm.org/text.asp?2013/31/4/424/118895
Can bacteria be used to determine our propensity for obesity? A study analysed gut microbial gene composition in non-obese and obese individuals and found marked differences in gene and species richness. Individuals with low richness exhibited increased adiposity, insulin resistance, dyslipidaemia and inflammation. Obese individuals with low microbial richness gained more body weight than those with high microbial richness. The investigators also demonstrated that analysis of just a few bacterial marker species was sufficient to distinguish between high and low bacterial richness ( http://links.ealert.nature.com/ctt?kn=93andms=NDI0MjIxODYS1andr=MjA1NTQ1ODUyMwS2andb=2andj=MjAwODQyMzkwS0andmt=1andrt=0 ).
A human coronavirus, called the Middle East respiratory syndrome coronavirus (MERS-CoV), was first identified in September 2012 in samples obtained from a Saudi Arabian businessman who died from acute respiratory failure. A report describes a family case cluster of MERS-CoV infection, including the clinical presentation, treatment outcomes and household relationships of three young men who became ill with MERS-CoV infection after hospitalization of an elderly male relative, who died of the disease. Twenty-four other family members living in the same household and 124 attending staff members at the hospitals did not become ill. Although an animal reservoir is suspected, none has been discovered yet (N Engl J Med. 2013 Jun 27;368(26):2487-94.). In this context, a study looked for the presence of coronaviruses (including MERS-CoV) in 1003 samples from wild bats collected in October 2012 and April 2013 in Saudi Arabia. Multiple alpha and beta coronavirus sequences were identified in 220 out of 732 roost feces samples and 7 of 91 rectal swab samples or fecal pellets. One amplified sequence of MERS-CoV from a Taphozous perforatus bat captured in October 2012 in Bisha, Saudi Arabia, matched fully with the MERS-CoV cloned from the index case-patient in Bisha ( http://wwwnc.cdc.gov/eid/article/19/11/13-1172_article.htm ).
The association of Gullain-Barre syndrome (GBS) with varied viral and bacterial infections has been postulated many times. A recent report describes a 50-year-old immunocompetent man with GBS associated with an autochthonous hepatitis E virus (HEV) infection. The patient presented with tetraparesis and elevated liver enzymes. HEV infection was confirmed serologically and by polymerase chain reaction (PCR) from blood and stool. Phylogenetic analysis revealed a novel HEV genotype 3 isolate closely related to other subgenotype 3c isolates from pig livers purchased locally. This could indicate an autochthonous, potentially food-related hepatitis E and possibly, the first report about a neurological syndrome associated with an HEV subgenotype 3c infection (Infection. 2013 Mar 20. [Epub ahead of print]).
Scale-up of antiretroviral therapy (ART) in resource-limited settings has drastically reduced HIV-related morbidity and mortality. However, challenges in long-term ART, adherence and HIV drug resistance (HIVDR) itself require monitoring in order to limit HIVDR emergence among ART-experienced populations and ensure regimen efficacy. A longitudinal study conducted from 2009 to 2011 in a cohort of 141 HIV-infected adult patients (age >21 years) at the National Social Insurance Centre Hospital in Yaounde, Cameroon, found low levels of HIVDR at baseline and at endpoint, suggesting a probable effectiveness of ART regimens used in Cameroon. However, the possible high rate of HIVDR among LTFUs limited the strength of these findings (PLoS One. 2013 Aug 26;8(8):e72680). In an attempt to provide effective therapy for HIV infection, an increasing number of broadly neutralising antibodies (bNAbs) against HIV-1 are being identified, and efforts are underway to optimise these for passive immunisation regimens. As yet, their capacity to neutralise different HIV-1 strains is limited. Now, a new study presents bispecific bNAbs (BibNAbs) with exceptional potency against all HIV-1 strains tested ( http://www.nature.com/nrd/journal/v12/n9/full/nrd4109.html?WT.ec_id=NRD-201309 ).
A new study sounds a note of caution for work on an universal vaccine for influenza. The research describes a phenomenon in which vaccination against one strain of flu actually seems to raise the risk of severe infection following exposure to a related but different strain, an effect called vaccine-associated enhanced respiratory disease. A swine model was used to evaluate mismatched influenza vaccine-associated enhanced respiratory disease (VAERD) after pH1N1 infection. Vaccinating pigs with whole inactivated H1N2 (human-like) virus vaccine (WIV-H1N2) resulted in enhanced pneumonia and disease after pH1N1 infection. WIV-H1N2 immune sera contained high titres of cross-reactive anti-pH1N1 haemagglutinin (HA) antibodies that bound exclusively to the HA2 domain but not to the HA1 globular head. No haemagglutination inhibition titres against pH1N1 (challenge virus) were measured. Epitope mapping using phage display library identified the immunodominant epitope recognised by WIV-H1N2 immune sera as amino acids 32 to 77 of pH1N1-HA2 domain, close to the fusion peptide. These cross-reactive anti-HA2 antibodies enhanced pH1N1 infection of Madin-Darby canine kidney cells by promoting virus membrane fusion activity. The enhanced fusion activity correlated with lung pathology in pigs. This study suggests a role for fusion-enhancing anti-HA2 antibodies in VAERD, in the absence of receptor-blocking virus neutralising antibodies. These findings should be considered during the evaluation of universal influenza vaccines designed to elicit HA2 stem-targeting antibodies (SciTransl Med. 2013 Aug 28;5(200):200ra114).
A botulism scare that damaged New Zealand's international reputation for providing top quality and safe dairy products was possibly a false alarm. New Zealand government officials stated that they had found no sign of the botulism bacterium after retesting ingredients used in recalled milk products. The dairy company, Fonterra, sparked a global recall of infant formula earlier in August 2013 after announcing it had discovered the presence of the botulism bacterium in some of its whey protein concentrate. But New Zealand's Ministry of Primary Industries announced on Wednesday, 28 Aug 2013, that they had conducted 195 tests in laboratories in New Zealand and the USA and had concluded that the bacterium in the whey concentrate was Clostridium sporogenes and not Clostridium botulinum, as initially identified by Fonterra's tests ( http://abcnews.go.com/International/wireStory/zealand-botulism-bacteria-milk-products-20089413 ).
Two recent immigrants from China were admitted to the same hospital in New York, 23 days apart for suspected foodborne botulism. Both patients had purchased fresh tofu from the same Chinese grocery in Queens, a New York City borough, and each had prepared home-fermented tofu using similar recipes. Similar fermentation practices at the two homes might have facilitated toxin production. Testing confirmed botulinum toxin type B in home-fermented tofu consumed by patient 1. Bulk tofu at the grocery in Queens was found to be sold in unrefrigerated, uncovered, water-filled bins. A trace back revealed that the grocery's fresh bulk tofu supplier at the time of the patients' purchases had gone out of business. This incident underscores the need for public health responders and clinicians to be aware of the association between botulism and fermented tofu (MMWR Morb Mortal Wkly Rep. 2013 Jul 5;62(26):529-32).
On Tuesday, 27 August 2013, officials in Kyrgyzstan scrambled to control the spread of bubonic plague that killed a rural boy last week. The easternmost district of Ak-Suu (IssykKul province) in the Central Asian country was on lockdown while police guarded the hospital where a 15-year-old was treated. The emergency ministry said that three more people from the same village as the victim were hospitalised with similar symptoms ( http://www.google.com/hostednews/afp/article/ALeqM5j7B5A6puttGZD9B2-Gvn-UcNeqcg?docId=CNG.eb497844a118d291deccabe9966d599a.4a1 ). The majority of human Yersinia pestis infections result from introduction of bacteria into the skin by the bite of an infected flea. Once in the dermis, Y. pestis can evade the host's innate immune response and subsequently disseminate to the draining lymph node (dLN). There, the pathogen replicates to large numbers, causing the pathognomonic bubo of bubonic plague. In a recent study, several cytometric and microscopic techniques were used to characterise the early host response to intradermal (i.d.) Y. pestis infection. Mice were infected i.d. with fully virulent or attenuated strains of dsRed-expressing Y. pestis, and tissues were analyzed by flow cytometry. The results of this study showed a very rapid, robust neutrophil response to Y. pestis in the dermis and indicated that the virulence plasmid pCD1 is important for the evasion of this response (MBio. 2013 Aug 27;4(5). pii: e00170-13).
Cryptococcosis can also be a differential diagnosis for multiple pulmonary masses. A case report describes cryptococcosis presenting with pulmonary masses and endobronchial obstructions. The patient'schest computed tomography (CT) scan showed masses in the right upper lobe and right hilar region, with evidence of narrowing of the right upper lobe bronchus. Lung tissue obtained by biopsy grew Cryptococcus neoformans on culture. The serum was positive for cryptococcal antigen, with a titre of more than 1:1280. The patient was successfully treated using liposomal amphotericin (B J Thorac Dis. 2013 Aug;5(4):E170-3).
Group A Streptococcal (GAS) necrotising fasciitis is a critical emergency. Patients with necrotising fasciitis principally present to emergency departments (EDs), but most studies are focused on hospitalised patients. An ED patient-based retrospective study was conducted to investigate the clinical characteristics, associated factors and outcomes of GAS necrotising fasciitis in the ED. It was found that the most prevalent underlying disease was diabetes mellitus (45.3%). Bullae were recognised in 37.3% of patients. One third of the cases were complicated by bacteremia. Polymicrobial infections were found in 30.7% of patients. The overall mortality rate for GAS necrotising fasciitis was 16%. (J Emerg Med. 2013 Aug 9. pii: S0736-4679(13)00578-7). Each year in the USA, GAS causes about 650-800 cases of necrotising fasciitis-an incidence rate of about 0.2 per 100 000 ( http://www.cdc.gov/features/necrotizingfasciitis/ ).