Category: Microbiology

Microbiological Assessment of Honey in México

Honey is a viscous sweet substance produced by bees from the secretions of plant nectars. It is a product from some regions of Mexico as a sugar supplement and for therapeutic purposes. Honey contains fructose and glucose with low level of water activity and high osmotic potential in humidity. In Mexico apiculture contains high economic and social value wherein forty five thousand producers depend on it. That accounts for almost 19 million beehives placing Mexico as the fifth producing and third exporting country in the world. Microbial characteristics of honey are the built-in biota of bees from the nectar of different flowers that kept overtime. This particular research study evaluates the microbial community of honey produced in Mexico.


Microbial Biota of Honey

Microbial contamination of honey occurs during extraction and handling including dust, air, dirt, flowers and digestive tract of honey bees. Microorganisms commonly found include Bacillus spp., Clostridium spp., Corynebacterium spp., Pseudomonas spp. and some bacteria found in sugars and plants. The official standard in Mexico stated that no more than 1000 CFU/g of non-pathogenic bacteria and 100 CFU/g of molds and yeast are acceptable. Since Mexico is one of the main honey producers that comprised at least 86 thousand tons to be exported.


The study reveals that out of 1,920 samples of honey 40.5% exceeded the limits permitted by the regulatory board. For the yeast and molds 18.1% and 17% of the samples showed more than 100 CFU/g respectively. With regard to Clostridium 12% the samples contained more than 100 CFU/g due to the bees contamination, nectar and external sources. There have been observations also that bee gut contains 27% gram positive bacteria including several species of Clostridium. Although honey has high osmolarity and low water activity yet development of microorganisms found on several sources. However, microbial contamination caused by handlers, equipment and crossed contamination can be controlled by standard sanitation and good manufacturing practices.


Since it reveals that over 40% from the samples did not complies specification for the presence of aerobic mesophilic bacteria. It gives emphasis to local producers the proper handling and minimizing the sources of contamination so it can fit the standard. If honey is used for therapeutic purposes better quality is vital and fulfills quality parameters to remove pathogens. Mexican honey of great percentage has been exported that is why maintaining good hygienic practices during manufacturing is very important.


Sources: Prepared by Joan Tura from  Revista Argentina de Microbiología

Volume 50, Issue 1 January–March 2018, Pages 75-80

Zika detection: comparison of methodologies

Zika virus is mainly spread by mosquitoes particularly female that is active during daytime to feed blood in order to lay eggs. This Zika virus when contact with human infects epidermal cells following the lymph nodes down to the bloodstream. Pathogenesis of this virus is similar to dengue fever showing symptoms like fever, joint pain, red eyes and skin rashes. Diagnosis of Zika virus is through blood test, urine or saliva test. Many countries have been affected by this virus which leads to some deaths.That is why this particular research came about to know the important tool to confirmed the etiology of this disease.


Zika virus Infection

Infection of Zika virus is normally established through serum test in order to detect viral nucleic acid. Diagnostic test of this virus have limitations that is why comparing the sensitivity and specificity on different tools is important to get reliable results. Accuracy of any diagnostic method is vital since Zika virus represent public health concern that has been usually misdiagnosed. Results of the study reveal that Zika virus is highly detected in urine and semen.


The Zika virus strains circulating worldwide has low viremia period that is why it compromise diagnostic accuracy. Laboratory examination rely only upon detection of virus RNA through body fluids including serum, plasma and amniotic fluid. Because detection of RNA in blood is usually low on third to fourth day after the onset of disease. That is why it is very important to further characterize the virus dynamics in blood. Whether increase level of virus in is correlated with the severity of the disease or due to immune responses.


Indeed, further developments is needed to reduce the limitations of current diagnostic test. Evaluation and thorough examination for widespread implementation is significant for Zika virus  to test accurately. Furthermore, crucial monitoring and preventive action is important to treat Zika fever. Hence, better assay is needed to enhanced diagnosis and surveillance of this virus.


Source: Prepared by Joan Tura from the Brazilian Journal of Microbiology

Volume 49, Issue 1, January–March 2018, Pages 144-147



A Symbiont Betrays Its Host

It came as a surprise to me recently to realize how much is known about the immune responses of plants and, moreover, how much there is to know. There is, I found, detailed molecular information about how our botanical cousins defend themselves against the onslaught of infectious agents. Perhaps most surprising is that plants and animals share basic mechanisms of immunity. Here I am referring to innate immunity, being that plants — like the invertebrates — do not have the adaptive immunity of vertebrates. Did these arise before the two realms diverged about one billion years ago? Or, alternatively, are they the result of convergent evolution? (more…)