Early Growth Response-1: Friend or Foe in the Heart?

Cardiovascular disease is a major cause of mortality and morbidity worldwide. Early growth response-1 (Egr-1) plays a critical regulatory role in a range of experimental models of cardiovascular diseases. Egr-1 is an immediate-early gene and is upregulated by various stimuli including shear stress, oxygen deprivation, oxidative stress and nutrient deprivation. However, recent research suggests a new, underexplored cardioprotective side of Egr-1. The main purpose of this review is to explore and summarise the dual nature of Egr-1 in cardiovascular pathobiology.

How do the severe acute respiratory coronavirus 2 (SARS-CoV-2) and its variants escape the host protective immunity and mediate pathogenesis?

Background

To protect the global population from the ongoing COVID-19 pandemic caused by the severe acute respiratory β-coronavirus 2 (SARS-CoV-2), a number of vaccines are currently being used in three dosages (i.e., along with the booster dose) to induce the immunity required to combat the SARS-CoV-2 and its variants. So far, several antivirals and the commercial vaccines have been found to evoke the required humoral and cellular immunity within a huge population around world. However, an important aspect to consider is the avoidance mechanism of the host protective immunity by SARS-CoV-2 variants.

Main body of the abstract

Indeed, such an immune escape strategy has been noticed previously in case of SARS-CoV-1 and the Middle East Respiratory Syndrome coronavirus (MERS-CoV). Regarding the SARS-CoV-2 variants, the most important aspect on vaccine development is to determine whether the vaccine is actually capable to elicit the immune response or not, especially the viral spike (S) protein.

Short conclusion

Present review thus focused on such elicitation of immunity as well as pondered to the avoidance of host immunity by the SARS-CoV-2 Wuhan strain and its variants.

Extended Spectrum Beta Lactamases-Producing Escherichia coli in Retail Chicken Meat from Khyber Pakhtunkhwa, Pakistan

In human diet, poultry meat is an important component due to the presence of vitamins, proteins and minerals. But poultry meat can be contaminated by pathogenic bacteria which are responsible for food borne infections. The current study was therefore aimed at identification of Escherichia coli, a common pathogen causing food borne infections, in chicken samples (n = 400) collected from three districts of KhyberPukhtunkhwa; Peshawar, Kohat and Nowshera. The isolates were identified by Gram staining, API strips and through PCR (Universal Stress Protein). A total of 174 samples were positive for E. coli among the collected chicken samples. The isolates were resistant to TE, NOR and NA while were sensitive to MEM, TZP and FOS. The results were statistically significant having value P ≤ 0.05 in ANOVA. The isolates showed different antibiotic resistance genes; OXA-1, CTX-M15, blaTEM, QnrS, TetA, AAC, AAD, sul1 and sul2 which is the molecular explanations of their antibiotic resistance pattern. The PCR products were sequenced by Next Generation Sequencing (NGS) and the results revealed mutations in AAC gene (M120T and R197T) and CTX-M15 (A85V, N122D, A148S and G247D).

To prevent and treat pathogenic diseases, the use of antimicrobial agents in animal husbandry are of utmost concern. The over-use and misuse of antimicrobial agents has made pathogenic E. coli multi drugs resistant making it a causative agent for many diseases in human beings. The results of the current study may be helpful for the physicians the better management of the diseases caused by E. coli.

COVID-19 vaccines: their effectiveness against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its emerging variants

BACKGROUND

The world has been suffering from the COVID-19 pandemic (officially declared by WHO in March 2020), caused by the severe acute respiratory β-coronavirus 2 (SARS-CoV-2) since the last week of December 2019. The disease was initially designated as a Public Health Emergency of International Concern on January 30, 2020. In order to protect the health of mass public, an array of research on drugs and vaccines against SARS-CoV-2 has been conducted globally. However, the emerging variants of SARS-CoV-2, i.e., Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2) variants which evolved in late 2020 and the Omicron variant (B.1.1.529) which emerged in November 2021 along with its subvariant BA.2 which was first identified in India and South Africa in late December 2021, have raised the doubt about the efficiency of the currently used vaccines especially in terms of the consistent potential to produce neutralizing antibodies targeting the viral spike (S) protein.

MAIN BODY OF THE ABSTRACT

The present review discussed the functional details of major vaccines regarding their efficiency against such variants during the pandemic. Overall, the mRNA vaccines have shown around 94% effectiveness; the adenovector vaccine showed approximately 70% efficacy, whereas Sputnik V vaccines showed around 92% effectiveness; the inactivated whole-virus vaccine CoronaVac/PiCoVacc and BBIBP-CorV showed a varying effectiveness of 65-86% according to the geographic locations; the subunit vaccine NVX-CoV2373 has shown 60-89% effectiveness along with the global regions against the wild-type SARS-CoV-2 strain. However, reduced effectiveness of these vaccines against the SARS-CoV-2 variants was noticed which is suggestive for the further administration of booster dose.

SHORT CONCLUSION

Maximum variants of SARS-CoV-2 emerged during the second wave of COVID-19; and extensive studies on the viral genomic sequences from all geographical locations around the world have been conducted by an array of groups to assess the possible occurrence of mutations(s) specially within the receptor binding domain of the viral spike (S) protein. Mutational similarities and the new or critical mutations within all variants have been clearly identified so far. The study of effectiveness of the currently used vaccines is also ongoing. The persistence of memory B cell action and the other immune components as well as the administration of booster dose is expected to mitigate the disease.

Overview of dreadful consequences of SARS-CoV-2 invasion in Italy from March 2020 to March 2022

BACKGROUND

The unpredicted pandemic disease COVID-19 first flared up adversely in Europe by imparting interminable force of infected and fatality cases to Italy. In late February 2020, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in northern Italy and swiftly proliferated to the entire country, albeit continuous to date (23 March 2022) with a lesser extent of deadliness. Current review focused on the invasions and the associated consequences by SARS-CoV-2 during the period of March 2020-March 2022.

MAIN BODY OF THE ABSTRACT

Initially, the lethality and transmissibility of the novel virus made Italy stunned within 1 month, the number of death cases reached 12,428 at the end of March 2020. The Italian Government announced an immediate emergency phase in entire country, educational institutions to local businesses, manufacturing works, cultural activities to elective activities were rescinded and all the hospitals to morgues were swamped, ensuing that fear of epidemic was impended. Besides, the Italian National Health System and Service coordinated massive public health interventions and conferred unprecedented efforts to limit the high mortality rate of the first wave of infection. Amidst 2 years of epidemic (as of 23 March 2022), Italy has documented 14,070,450 (23.74% of the population) confirmed infected cases, 12,685,306 (21.41% of the population) healed cases, 158,254 death cases (0.27% of the population) and ranking 9th worldwide in the number of deaths.

SHORT CONCLUSION

Based on publicly available Italian Ministry of Health COVID-19 data, current review has comprehended region-wise total infected cases, death cases and healed cases for three consecutive years 2020-2022 to foresee different patterns of the regional outbreak and gradual subservience. At a glance, we highlighted the overview of the exhaustion and exertion of COVID-19 crisis throughout the periods in Italy.

A review on the induction of host immunity by the current COVID-19 vaccines and a brief non-pharmaceutical intervention to mitigate the pandemic

BACKGROUND

To mitigate the current COVID-19 pandemic by the severe acute respiratory coronavirus 2 (SARS-CoV-2), designing of repurposed antiviral drugs and the development of vaccines using different platforms have been the most significant work by the scientists around the world since the beginning of 2020.

MAIN BODY OF THE ABSTRACT

While positive results are being noticed with the currently used vaccines, the emerging variants of SARS-CoV-2 as well as the second wave of COVID-19 pandemic put the global public health in the deadliest health issue. Present review attempted to focus on the development of the current COVID-19 situation in the light of knowledge gathered from the recently published literature. An important facet regarding the COVID-19 severity is the avoidance of host immunity by the SARS-CoV-2 and its variants. Indeed, the genetic similarities between SARS-CoV-2, SARS-CoV-1 and the Middle East respiratory syndrome coronavirus (MERS-CoV) showed the viral escape strategies of the protective host immunity which appeared as the major problem for the effective vaccine development.

SHORT CONCLUSION

Present review discussed the prescribed platforms of vaccine development and pondered on the cellular and humoral immune responses by vaccines; and apart from vaccination approaches, non-pharmaceutical intervention approaches have also been pondered based on modeling rules.

Prevalence of parasites in selected captive bird species

Blood and fecal samples of chukar partridge (Alectoris chukar), albino pheasant (Phasianus colchicus), silver pheasant (Lophura nycthemera), rose-ringed parakeet (Psittacula krameri) and turkeys (Meleagris gallopavo) were analyzed to check parasitic prevalence. To record parasites these five avian species were placed kept in separate cages at Avian Conservation and Research Center, Department of Wildlife an Ecology, University of Veterinary and Animal Sciences, Lahore, Pakistan. 100 fecal and 100 blood samples for each bird species were inspected to analyze internal parasites. During present study, 17 species of endoparasites 14 from fecal samples and three from blood were examined. Two species of ectoparasites i.e. mite Dermanyssus gallinae 42% and fowl ticks Args persicus 41%were studied. Blood parasites included Plasmodium juxtanucleare 50%, Leucoctoyzoon simond having parasitic prevalence 40%, and Aegyptinella pullorum having parasitic prevalence of 40%. Parasitic species recorded from fecal samples included 6 species of nematodes viz. Allodpa suctoria 2%. Syngamus trachea with parasitic prevalence of 60%, Capillaria annulata 37.5%, Ascardia galli 24%, Capillaria anatis 40% and Heterakis gallinarum 28.3%. Similarly, two species of trematodes viz. Prosthogonimus ovatus having parasitic prevalence of 50% and Prosthogonimus macrorchis 21% were also documented from fecal avian samples . Single cestode species Raillietina echinobothrida having parasitic prevalence of 72% and 3 protozoan species i.e. Eimeria maxima having parasitic prevalence of 21%, Giardia lamblia 41% and Histomonas meleagridis 18% were documented during corpological analysis. In our recommendation, proper sanitation, medication and vaccination of bird's enclousres are suggested to avoid parasites.

Genetic variations and phylogenetic relationship of genus Uromastyx from Punjab Pakistan

During the present study, specimens were collected from selected sites of Cholistan desert and Kalabagh Game Reserve, Punjab province, Pakistan. Each captured specimen was tagged with voucher number and morphometric measurements were taken. The average snout to vent length was 172.559±1.40 mm and average weight was 92.1±1.30 g. The DNA of Uromastyx hardwickii was amplified and sequenced using 16S rRNA primer set. The obtained DNA sequence has shown reliable and clear species identification. After trimming ambiguous bases, the obtained 16S rRNA fragment was 520 bp while 16S rRNA fragments aligned with closely matched sequence from NCBI comprised of 510 bp. Closely matched sequences of genus Uromastyx were retrieved from NCBI in blast searches. Neighbour-joining tree of genus Uromastyx was constructed based on p-distance using MEGA X. The mean intraspecific variation was 0.095±0.01 while intraspecific variation was ranging from 0-1%. Similarly, interspecific variation of Uromastyx hardwikii with Saara asmussi, Uromastyx alfredschmidti, Uromastyx geyri, Uromastyx thomasi, Uromastyx alfredschmidti was 0-12%, 0-19%, 0-19%, 0-20%, 12-19% respectively. The newly produced DNA was submitted to NCBI and accession number was obtained (MW052563.1). Results of current study provided information about the molecular and morphological identification of Genus Uromastyx. In our recommendation, comprehensive molecular based identification of Pakistan's reptiles is required to report any new or subspecies from country.

COVID-19 Pandemic and the Convalescent Plasma Therapy: Possible Benefits and Risks

Purpose of Review

COVID-19 pandemic has been the major threat to the global public health for a year (last of 2019-till date); and unfortunately, there is still as no specific antiviral agent which can be effectively used against this disease curation. Present review focused on the application of the convalescent plasma (CP) therapy as a quick remediation of the disease severity.

Recent Findings

While several drugs have been repurposed based on a number of completed clinical trials together with a huge ongoing effort to develop appropriate vaccine against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the therapeutic approach of the CP therapy appears to be one of the effective methods to rescue the severely affected COVID-19 patients. Such a therapy based on passive immunity evolved from the SARS-CoV-2-infected patients who have fully recovered from COVID-19; and hence these individuals are quite likely to possess high titers of the SARS-CoV-2-neutralizing immunoglobulins (antibodies). However, there are some risks such therapy, and its effectivity also appeared doubtful in some cases. Thus, the current review discussed the issues raised by the administration of such plasma into the SARS-CoV-2-infected individuals.

Summary

Application of CP therapy has been conducted since long time; and for the mitigation of COVID-19 severity, such pharmaceutical strategy is also being employed in spite of several risks which actually can be monitored as well as optimized in order to combat the SARS-CoV-2 infection.

Interspecific variations in external and internal egg quality among various captive avian species from Punjab, Pakistan

Present study was planned to determine variations in external and internal quality egg parameters of different avian species including ostrich Struthio camelus, ducks Anas platyrhynchos, chicken Gallus gallus, turkeys Meleagris gallopavo and grey francolin Francolinus pondicerinus. All the birds were kept under similar rearing conditions. A total of 150 eggs were collected for each species to record external features of these eggs. Statistically significant (p<0.05) variations were recorded in egg weight, egg length and egg width between ostrich, ducks, chicken, turkey and quail eggs. Significantly (p<0.05) higher egg weight, egg length and egg width was observed for ostrich eggs while the same was lowest for grey francolin eggs. Similarly, significantly (p<0.05) greater shape index and egg volume values were observed for ostrich eggs while lowest shape index values were recorded for turkey eggs and egg volume was lowest for grey francolin. Significantly, higher (p<0.05) values of egg density were noted for eggs of the quail and the same were lowest for ostrich eggs. Non-significant variations in egg density values were observed between eggs of the ducks, chicken, turkey and grey francolin. It has been concluded that the positive correlations between the internal and external egg quality traits indicated that the traits can be improved through selection.

Developmental Status of the Potential Vaccines for the Mitigation of the COVID-19 Pandemic and a Focus on the Effectiveness of the Pfizer-BioNTech and Moderna mRNA Vaccines

Purpose of Review

Along with the continued in silico-based studies for drug designing and repurposing followed by the corresponding cell culture studies, the ongoing clinical trials with some completed regarding finding the drug efficacy and the vaccine development against the severe acute respiratory coronavirus 2 (SARS-CoV-2) have been the most functional and indispensable issue during the current COVID-19 pandemic within 2020 and onward. The present review attempted to figure out the update on this effective vaccine and discussed the other promising vaccines.

Recent findings

A range of investigations on the SARS-CoV-2 genomics, on its similarities with SARS-CoV-1, and with the Middle East respiratory syndrome coronavirus (MERS-CoV) have been accomplished and the host immune dodging mechanisms by the SARS-CoV-2 have been unraveled which in turn led the scientists around the world to work rigorously on the vaccine development. Working with various vaccine platforms so far revealed the efficacy of the mRNA-1273 vaccine as the most effective one as resulted through the clinical trials which resulted in 95% positive output.

Summary

Although currently commercialized mRNA-1273 vaccine appears to be effective, still several points are to be pondered regarding the sustainability of vaccine efficacy against the rising variants of SARS-CoV-2.

Microorganisms and cardiovascular diseases: importance of gut bacteria

Cardiovascular diseases including myocardial infarctions, myocarditis, strokes, coronary artery disease, chronic granulomatous disease, atherosclerotic cardiovascular disease, etc. can be regarded as the severe health trouble round the globe. The reasons behind the heart related complications have been well chalked our so far. Interestingly, along with the non-infectious reasons, an array of bacteria, fungi, parasites and viruses is known to cause different types of heart complications. Unfortunately, the role of microorganisms in inducing heart diseases is not that much known by the mass community in the underdeveloped and even in the developing countries over the world. However, among the microorganisms causing heart diseases, the multifaceted bionetwork by the gut microorganisms especially drew the interests of microbiologists. The impairment of cardiac membrane, the metabolic malfunction of heart, and imbalance in the functionality of the immune cells by the alternation in the composition of gut microorganisms are currently not unknown. Present review outlined the onset of heart diseases caused by the gut microflora in a simple way which would be important in public health regard.

Antiviral drugs against severe acute respiratory syndrome coronavirus 2 infection triggering the coronavirus disease-19 pandemic

So far, lots of analyses have been conducted to invent the appropriate therapeutic targets for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The category and the strategies for treating the virus are described in this review together with mentioning some specific drugs. Of them, saikosaponin possesses affinity of the drug toward nonstructural protein 15 and the spike glycoprotein of the SARS-CoV-2. The nucleotide inhibitors such as sofosbuvir, ribavirin, galidesivir, remdesivir, favipiravir, cefuroxime, tenofovir, and hydroxychloroquine (HCHL), setrobuvir, YAK, and IDX-184 were found to be effective in binding to SARS-CoV-2 RNA-dependent RNA polymerase. From the antimalarial and anti-inflammatory category, chloroquine and its derivative HCHL have already been approved by the U.S. Food and Drug Administration for emergency treatment of SARS-CoV-2 infection. The other drugs such as favipiravir and lopinavir/ritonavir under the antiviral category, the angiotensin-converting enzyme 2 (the renin-angiotensin system inhibitors), remdesivir (RNA polymerase inhibitor) from antiviral category, cepharanthine from anti-inflammatory category, etc., have been pointed based on the previous literature published. Besides, the assessment of the drug repositioning candidates with the related targets is also significant for the viral mitigation.

Reemergence of dengue virus in Bangladesh: Current fatality and the required knowledge

The current fatality of dengue among the Bangladeshi population has drawn the interest of the public health professionals primarily to focus on the environmental, social, and clinical reasoning as well the possible remedies. This year, in 2019, the dengue situation in Bangladesh has appeared with all its dreadful effects leading to the highest death cases due to dengue virus (DENV) infection. According to the Directorate General of Health Services report, this year (2019) the number of DENV-infected people has appeared to be around five times higher (approximately 50,000 cases so far) compared with the last year, 2018 (around 10,000 cases). The present review discussed the current epidemics of dengue infection in Bangladesh as well the possible means of disease curing in terms of general preventive concepts. However, besides the precise treatment of the dengue-affected patients, the knowledge on DENV genome and on the protective immunity against such reemerging disease is essential.

Microbiological analysis and determination of antimicrobial traits of green banana (Musa spp.) and papaya (Carica papaya)

Green banana (Musa spp.) and papaya (Carica papaya), which are commonly consumed as vegetables, are fruits with lots of health benefits. Due to their various medicinal applications, both the fruits are likely to contain antimicrobial properties. In this regard, present study was undertaken to determine the microbiological quality as well as the anti-bacterial traits of fresh green banana and papaya. To serve the purpose, a total of 12 samples (6 green bananas and 6 green papaya) were collected from different local and super shops as well from cultivation land of some villages of Bangladesh. The samples contained the microbial contamination with viable bacteria and fungi up to 107cfu/g and 103 cfu/g. Among the pathogenic bacteria, Staphylococcus spp. Pseudomonas spp. and Vibrio spp. were predominant as found in most of the samples in average of 102 cfu/g. Whereas Escherichia coli, Salmonella spp. and Shigella spp. were totally absent in all the samples. On the other hand, Klebsiella spp. was present in same samples. Additionally, the anti-bacterial poverties of the samples were chalked out. The in-vitro antimicrobial activities of the ethanolic, methanolic and hot water extracts of the samples were noticeably found against all the tested bacteria. Overall, present study revealed that both the green fruit samples were highly contaminated although they have antimicrobial activities. Thus, consumers’ awareness on the risk of consuming pathogen contaminated vegetables needs to be re-awakened and further investigations are required for potential antimicrobial properties. Stamford Journal of Microbiology, Vol.8(1) 2018: 41-45

Zika virus: Epidemiological study and its association with public health risk

Propagation of Zika virus has become an alarming global public health issue. The infection is spreading rapidly to different countries by several methods, especially by the transmission through traveling. Bangladesh is also at a risk to be affected with such newly viral infections. Though the virus initially appears to cause mild problems, the long term effects are more devastating to the next generation as seen in case of the delivery of the microcephalic babies. Current review discussed the epidemiologic era of the virus; i.e., the administration of Zika virus in the non-human mammals and finally to the human host across the world. Typical sign-symptoms which can often be considered as dengue or chikungunya for their similarities have been stated. The diagnosis of Zika virus, the protective measures taken by mass people as well as the actions that should be endorsed to prevent acquisition of the infection from travelers are discussed.

Prevalence of Pathogenic Bacteria in Shrimp Samples Collected from Hatchery, Local Markets and the Shrimp Processing Plant

Export quality frozen shrimps comprise as one of the major economic interests in Bangladesh. During cultivation or processing and packaging, microbial condition is an important issue to maintain the quality of shrimps. Eight shrimp samples, of which, one from hatchery, 3 from local markets and 4 processed export quality samples were studied for microbiological risk assessment (MRA). One hatchery, three market and two export quality shrimp samples were found to contain bacterial pathogens probationary identified as Escherichia coli, Klebsiella spp., Vibrio spp., Aeromonas spp., Pseudomonas spp., Listeria spp., Shigella-like organisms, Staphylococcus aureus, and Salmonella spp. and two other processed export quality shrimp samples were completely free of pathogens of any type. Surprisingly, the later two processed export quality shrimp samples showed antibacterial activity against E. coli, Klebsiella sp. and Vibrio sp.Bangladesh J Microbiol, Volume 29, Number 1, June 2012, pp 7-10

Anti-Bacterial Activity of Natural Plants on Fish Pathogens Isolated from Different Ponds of Dhaka City

In aquaculture, the incidence of bacterial resistance towards synthetic antibiotics has become a serious problem. Therefore, current research has been focused on detecting the presence of pathogenic bacteria in water bodies and finding a novel therapy against pathogens imparted by the natural products replacing the use of synthetic antibiotics. A total of 10 pond water samples were analysed to determine the pathogenic load employing conventional cultural and biochemical tests. Anti-bacterial activities of natural plants on fish pathogens were determined using the agar-well-diffusion method. All the water samples studied high heterotrophic bacteria counts, which were upto 109 cfu/ml. Among bacterial pathogens, Pseudomonas spp. and Vibrio spp. were found to be present in 6 samples and Aeromonas spp. in 2 samples. The in vitro anti-bacterial activity of the herbal plant extracts against the bacterial pathogens revealed that most of the plant extracts are effective against the pathogenic bacterial isolates.Bangladesh J Microbiol, Volume 31, Number 1-2,June-Dec 2014, pp 9-12

Influence of temperature on the growth of Pseudomonas putida

Lots of reports on the generation of stress by increase in temperature in the bacterial cells especially in Escherichia coli has been observed so far. Current study further emphasized such effect on the cells of Pseudomonas putida (SUBP03). Conventional methods relating growth assessment of bacteria were employed. The optical density of bacterial cells at 600 nm (OD600) in the minimal broth along with the culturable cells were assessed in the form of colony forming units (CFUs) in the minimal agar media at different temperatures (27 °C, 30 °C, 33 °C, 37 °C and 40 °C). Morphological observations were made to further clarify the bacterial physiology and the spot tests were performed to examine the cell viability. Cells of P. putida (SUBP03) were found to grow vigorously at 30 °C, while the growth was found to decline at lower temperature (27 °C) and along with the increase in temperature (at 33 °C, 37 °C and 40 °C). However, the morphological changes were insignificant. Furthermore, cells were noticed to completely lose culturability at 40 °C after 48 hours.Stamford Journal of Microbiology, Vol.5(1) 2015: 9-12

Safe usage of cosmetics in Bangladesh: a quality perspective based on microbiological attributes

The present review attempted to emphasize on the microbiological quality of the commonly used cosmetics item by the majority of the Bangladeshi community. The abundance of contaminating microorganisms has been quantitatively discussed and the possible health risk has been focused upon usage of these items. Only a very few research efforts have been conducted on the cosmetic items in Bangladesh so far. The microbiological contamination aspects have been portrayed in this review using the information collected from a substantial number of cosmetic items which were earlier subjected to extensive microbiological and biochemical analyses. The prevalence of bacteria, fungi and the specific pathogenic microorganisms has been discussed based on research so far locally conducted on the finished items sold in markets, especially within the Dhaka metropolis. The laboratory scale experiments revealed the presence of enormous number of bacteria, actinomycetes and fungi within the commonly used cosmetics. Conversely, the anti-bacterial activity was noticed in some of the products which might be in favor of the user safety. The prevalence of pathogenic microorganisms in the cosmetic items certainly raises a substantial public health issue. The necessity of the routine microbiological testing of the commonly used cosmetic items as well as the legislative measures to mitigate the contamination problem is thus of great significance.

Survival of Bacillus spp. SUBB01 at high temperatures and a preliminary assessment of its ability to protect heat-stressed Escherichia coli cells

Background

The bacterial stressed state upon temperature raise has widely been observed especially in Escherichia coli cells. The current study extended such physiological investigation on Bacillus spp. SUBB01 under aeration at 100 rpm on different culture media along with the high temperature exposure at 48, 50, 52, 53 and 54 °C. Bacterial growth was determined through the enumeration of the viable and culturable cells; i.e., cells capable of producing the colony forming units on Luria–Bertani and nutrient agar plates up to 24 h. Microscopic experiments were conducted to scrutinize the successive physiological changes. Suppression of bacterial growth due to the elevated heat was further confirmed by the observation of non-viability through spot tests.

Results

As expected, a quick drop in both cell turbidity and colony forming units (~10⁴) along with spores were observed after 12–24 h of incubation period, when cells were grown at 54 °C in both Luria–Bertani and nutrient broth and agar. The critical temperature (the temperature above which it is no longer possible to survive) of Bacillus spp. SUBB01 was estimated to be 53 °C. Furthermore, a positive impact was observed on the inhibited E. coli SUBE01 growth at 45 and 47 °C, upon the supplementation of the extracellular fractions of Bacillus species into the growing culture.

Conclusions

Overall the present analysis revealed the conversion of the culturable cells into the viable and nonculturable (VBNC) state as a result of heat shock response in Bacillus spp. SUBB01 and the cellular adaptation at extremely high temperature.

Influence of heat shock and osmotic stresses on the growth and viability of Saccharomyces cerevisiae SUBSC01

Background

With a preceding scrutiny of bacterial cellular responses against heat shock and oxidative stresses, current research further investigated such impact on yeast cell. Present study attempted to observe the influence of high temperature (44–46 °C) on the growth and budding pattern of Saccharomyces cerevisiae SUBSC01. Effect of elevated sugar concentrations as another stress stimulant was also observed. Cell growth was measured through the estimation of the optical density at 600 nm (OD₆₀₀) and by the enumeration of colony forming units on the agar plates up to 450 min.

Results

Subsequent transformation in the yeast morphology and the cellular arrangement were noticed. A delayed and lengthy lag phase was observed when yeast strain was grown at 30, 37, and 40 °C, while at 32.5 °C, optimal growth pattern was noticed. Cells were found to lose culturability completely at 46 °C whereby cells without the cytoplasmic contents were also observed under the light microscope. Thus the critical growth temperature was recorded as 45 °C which was the highest temperature at which S. cerevisiae SUBSC01 could grow. However, a complete growth retardation was observed at 45 °C with the high concentrations of dextrose (0.36 g/l) and sucrose (0.18 g/l). Notably, yeast budding was found at 44 and 45 °C up to 270 min of incubation, which was further noticed to be suppressed at 46 °C.

Conclusions

Present study revealed that the optimal and the critical growth temperatures of S. cerevisiae SUBSC01 were 32.5 and 45 °C, respectively; and also projected on the inhibitory concentrations of sugars on yeast growth at that temperature.

Emerging diseases in Bangladesh: Current microbiological research perspective

Bangladesh has experienced a variety of diseases caused by natural dissemination of an array of pathogenic microorganisms into the environment. While cures for these diseases largely depend on the medication strategies of physicians, determining the reasons for disease persistence as well for the onset of reinfection is also essential. Routine diagnosis of common diseases usually means treatment with a range of appropriate medicines; however, failure of these medications because of the drug resistance of microorganisms accompanied by a lack of alertness about the etiology of diseases often leads to fatal results. The present review reports on emerging diseases in Bangladesh and focuses on associated microbiological research into ongoing diseases including enteric, urinary tract, and malarial complications. The viruses associated with acquired immunodeficiency syndrome and hepatitis are also discussed.

Microbiological profiling and the demonstration of in vitro anti-bacterial traits of the major oral herbal medicines used in Dhaka Metropolis

Present study attempted to assess the level of microbiological contamination in oral herbal medicines, frequently used for medications, through conventional cultural and biochemical tests along with the antibiogram of the isolates. Moreover, the anti-bacterial potential of the herbal medicines was also aimed to be checked by the agar well diffusion method and minimum inhibitory concentration (MIC) assay. Out of 10 categories of liquid oral herbal medicine samples (n = 50) studied, all were found to be contaminated with bacteria (10(3)-10(5) cfu/mL), specifically with Staphylococcus spp. in 8 samples; while 2 samples harbored Klebsiella spp. Fungal presence was observed only in one sample. Study of antibiogram revealed Klebsiella spp. to be strongly resistant against penicillin G and erythromycin, whereas S. aureus possessed 80% sensitivity. The in vitro anti-bacterial activity was observed in 7 samples. Of them, one sample was found to exhibit the activity against almost all the test bacteria and another was found effective against 5 out of 8 test bacteria. Five samples showed the activity within a minor range while 3 samples were devoid of such trait. Samples 2 and 4 were found to stall the bacterial growth below 10 mg/mL of concentration in MIC test. Overall, the prevalence of specific pathogens was not so significant in the samples studied as well as only one drug-resistant isolate was identified. Besides, the anti-bacterial trait of 5 samples indicated that most of herbal medicines might be considered effective for medication.

Molecular characterization of the virulent microorganisms along with their drug-resistance traits associated with the export quality frozen shrimps in Bangladesh

Current investigation characterized export quality shrimp samples in terms of pathogenic load along with the drug-resistance traits of the isolates, and detected the major virulent genes present in those isolates. Among the 30 such shrimp samples (15 each of Macrobrachium rosenbergi or Golda and Penaeus monodon or Bagda) studied, almost all were found to be contaminated with a huge load of bacteria (10⁶–10⁸ cfu/g) and fungi (10⁴–10⁵ cfu/g). Among the specific pathogens, presence of Escherichia coli, Vibrio spp., Aeromonas spp., Klebsiella spp., Shigella spp., Staphylococcus spp. and Listeria spp. were detected, of which most were likely to be resistant against commonly used antibiotics. Gene specific polymerase chain reaction (PCR) study revealed the presence of eae gene in E. coli, aero specific gene in Aeromonas spp., and sodB gene in Vibrio spp. Together with the huge extent of microbial contamination with a drug-resistance attribute, presence of such virulent genes further projects the probable public health risk upon consumption of the export quality shrimps.

Molecular approaches for detection of the multi-drug resistant tuberculosis (MDR-TB) in Bangladesh

The principal obstacles in the treatment of tuberculosis (TB) are delayed and inaccurate diagnosis which often leads to the onset of the drug resistant TB cases. To avail the appropriate treatment of the patients and to hinder the transmission of drug-resistant TB, accurate and rapid detection of resistant isolates is critical. Present study was designed to demonstrate the efficacy of molecular techniques inclusive of line probe assay (LPA) and GeneXpert MTB/RIF methods for the detection of multi-drug resistant (MDR) TB. Sputum samples from 300 different categories of treated and new TB cases were tested for the detection of possible mutation in the resistance specific genes (rpoB, inhA and katG) through Genotype MTBDRplus assay or LPA and GeneXpert MTB/RIF tests. Culture based conventional drug susceptibility test (DST) was also carried out to measure the efficacy of the molecular methods employed. Among 300 samples, 191 (63.7%) and 193 (64.3%) cases were found to be resistant against rifampicin in LPA and GeneXpert methods, respectively; while 189 (63%) cases of rifampicin resistance were detected by conventional DST methods. On the other hand, 196 (65.3%) and 191 (63.7%) isolates showed isoniazid resistance as detected by LPA and conventional drug susceptibility test (DST), respectively. Among the drug resistant isolates (collectively 198 in LPA and 193 in conventional DST), 189 (95.6%) and 187 (96.9%) were considered to be MDR as examined by LPA and conventional DST, respectively. Category-II and -IV patients encountered higher frequency of drug resistance compared to those from category-I and new cases. Considering the higher sensitivity, specificity and accuracy along with the required time to results significantly shorter, our study supports the adoption of LPA and GeneXpert assay as efficient tools in detecting drug resistant TB in Bangladesh.

Reduction of CD4 count induces opportunistic infections in people living with HIV (PLHIV)

Objective: Human immunodeficiency virus (HIV), a lentivirus (member of the retrovirus family) causing acquired immunodeficiency syndrome (AIDS), weakens the immune system of the body and hence associates different opportunistic infections. Present study undertook a survey on opportunistic infections. Materials and Methods: Data were collected from both HIV carriers (CD4 count more than 250/mL of blood) and AIDS patients (CD4 count less than 250/mL of blood). Results: Analyses of the data revealed that diarrhoea, pulmonary tuberculosis, gland tuberculosis, skin lesions and fever were the common opportunistic infections. Conclusion: It can be summarized that HIV infected patients having a reduced CD4 count (<250/mL) encounter different opportunistic infections and some of these infections could be continual for long as well. DOI: http://dx.doi.org/10.3329/bjms.v13i3.19151 Bangladesh Journal of Medical Science Vol.13(3) 2014 p.285-291

Drug-resistant bacterial pathogens in milk and some milk products

Purpose

– Current study was carried to detect the presence of pathogenic bacteria including the drug-resistant ones from milk and milk products. The paper aims to discuss these issues.

Design/methodology/approach

– Twenty-six raw milk samples from ten different areas, 28 pasteurized milk samples from 12 different companies and 26 yogurt samples from ten different sources in Dhaka city were microbiologically analyzed through cultural and biochemical identification of the isolates. Drug resistance trait was also determined by the Kirby-Bauer method on Muller-Hinton agar.

Findings

– Out of 80 samples studied, 74 were found to harbor pathogens within a range of 102-104 cfu/ml, including Escherichia coli, Salmonella spp., Staphylococcus aureus, and Vibrio spp. The study of antibiogram revealed that most of the isolates were resistant against most of the commonly used antibiotics.

Research limitations/implications

– Employment of only cultural/ biochemical tests excluding the molecular detection of virulence and/or antibiotic resistance genes might stand as a shortfall of the study. Nevertheless, such basic approach of microbiology can make this type of study replicable in the resource poor settings in the other developing countries.

Practical implications

– Routine detection of drug-resistant bacteria can further unveil the complications in chemotherapy during the endemic food borne diseases.

Social implications

– The study outcome/knowledge would aid to a better public health management especially in the developing countries.

Originality/value

– The presence of drug-resistant pathogenic bacteria in most of the tested milk samples poses a great public health threat, especially to the children. Therefore, the study revealed the necessity of maintaining proper hygienic practice and care in handling and processing of milk and milk products.

Microbial contamination in herbal medicines available in Bangladesh

Plants have long been used as herbal medicines in many countries. However, microbial contamination of these medicines may affect human health. Present study was performed to assess the pathogenic proliferation in the locally available commercial herbal oral medicines. The pathogenic load was compared with the microbiological standard given by the British Pharmacopoeia. Out of 85 oral liquid samples, 2 were found to be highly contaminated with a total aerobic bacterial load of 1.24 x 10(5) cfu/ml, 10 samples were contaminated with fungi (1.2 x 10(4)-6.3 x 10(4) cfu/ml). Tests for specific pathogens were carried out. One sample showed contamination by coliforms but none of the samples were contaminated by Salmonella spp. and Shigella spp. Among 40 semisolid samples, one showed to be contaminated with bacteria (1.93 x 10(5) cfu/g) and 5 samples consisted of fungal load ranging between 1.5 x 10(4)-2.2 x 10(4) cfu/g. The presence of bacteria and fungi in these samples thus suggest the fact that aseptic handling is necessary during processing of oral herbal medicines.

Evaluation of the effectiveness of BACTEC MGIT 960 for the detection of mycobacteria in Bangladesh

OBJECTIVE

Tuberculosis (TB) caused by Mycobacterium tuberculosis has been identified as a re-emerging infectious disease with public health importance globally. Exploitation of new laboratory techniques for precise identification of mycobacteria in clinical specimens is of great importance to improve the diagnosis as part of the global TB control efforts.

METHODS

The current study was conducted for the evaluation of BACTEC MGIT 960 method in comparison with Lowenstein-Jensen (LJ) culture and light emitting diode (LED) fluorescence microscopy for isolation of mycobacteria among TB suspects from Bangladesh. A total of 421 specimens were tested with these methods.

RESULTS

Among the tested samples, 3.6% (n=15) were LED fluorescence microscopy positive; while 18 (4.2%) and 45 (10.6%) were recovered from LJ and MGIT 960 culture. The relative positivity found through MGIT 960 system were 60% and 66.7% higher than that of LJ culture and LED fluorescence microscopy, respectively. Recovery rate of Mycobacterium tuberculosis complex ([MTC], 21 by MGIT and 16 by LJ culture) and non-tubercular mycobacteria ([NTM], 24 by MGIT and 2 by LJ culture) by MGIT 960 was 24% and 96% greater, respectively than LJ culture. Moreover, MGIT 960 was found to be highly sensitive (100%), specific (93.3%), accurate (93.6%) and a more rapid method in detecting mycobacteria when compared with LJ culture.

CONCLUSION

Extended recovery of NTM and MTC through MGIT 960 urged frequent application of this method to detect mycobacteria more effectively and rapidly.

Prevalence and antibiogram profile of uropathogens isolated from hospital and community patients with urinary tract infections in Dhaka City

Urinary tract infection (UTI) is increasingly rising in Bangladesh due to the development of resistance of causative pathogens against commonly prescribed antibiotics. Present study attempted to examine the prevalence of such uropathogens and their antibiogram profiles. Among 462 urine samples collected from patients with UTI, 100 were found to be culture positive. Escherichia coli (70%) was predominating, while Klebsiella spp. (11%) and Enterococcus spp. (6%) were also prevalent. About 96% uropathogens were sensitive against imipenem, and 75% against amikacin. The resistance rate of E. coli and Klebsiella spp. against ampicillin was 98.5 and 100%, respectively, and to cefotaxime, 84.3 and 72.8%, respectively. More than 80% resistance against these antibiotics was scored for other isolates. The frequency of drug resistance was found to be comparatively elevated in E. coli, Pseudomonas spp. and Proteus spp. Overall, the present investigation emphasized the need for routine screening of antibiotic resistance to promote effective medication against UTI. DOI: http://dx.doi.org/10.3329/jbas.v37i1.15681 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 1, 57-63, 2013

Effects of plasmid curing on Rhizobium spp

Present study was carried out to determine the difference between the wild type rhizobial strains and plasmid cured strains for some important characteristics such as antibiotic resistance. The rhizobial strains were isolated from locally produced legumes of different varieties such as Pisum sativum, Sesbania aculeata, Vigna mungo, Phaseolus vulgaris, Lens culinaris and Arachis hypogea.They were purified and subjected to various morphological, cultural and biochemical analysis, and also to antibiogram. All the strains showed resistance against amoxicillin and bacitracin, and exhibited higher (50% or more) resistance against ampicillin, erythromycin, nalidixic acid and strptomycin. The isolates were then subjected to plasmid profile analysis. To determine appropriate dose for plasmid curing, Sesbania nodulating rhizobial strain was treated with different concentrations of acridine orange (plasmid curing agent). Rhizobial growth was found in yeast mannitol broth after curing with 30 ?g/ml of acridine orrange. The rhizobial strain was found to be sensitive against amoxicillin, streptomycin and ampicillin after plasmid curing and no exopolysaccharides were found. The present study reveals that the plasmid in rhizobial species might confer the antibiotic resistance and possibly involve in maintaining symbiotic relationships. DOI: http://dx.doi.org/10.3329/sjm.v2i1.15212 Stamford Journal of Microbiology, Vol.2(1) 2012: 34-37

Prevalence of Vibrio cholerae in human-, poultry-, animal excreta and compost samples

Transmission of Vibrio cholerae might take place in water bodies that often undergo contamination with human-, poultry- and animal excreta. In the present study, wastes from all three categories were analyzed microbiologically. Twelve poultry excreta samples, 12 human excreta samples and 12 cowdung samples were examined for the presence of V. cholerae. High prevalence of V. cholerae was found in each of the samples and the highest prevalence was observed for human excreta samples (2.2x108 cfu/g). Besides, 24 compost samples, which were prepared using human feces, were tested. The load of V. cholerae was found lower in the compost samples (from 0 to 2.2x103 cfu/g) than that of the excreta samples. The study of antibiogram showed that all the isolates were resistant against ampicillin, erythromycin, tetracycline, chloramphenicol, nalidixic acid, meropenem and cefotaxime. DOI: http://dx.doi.org/10.3329/sjm.v2i1.15213 Stamford Journal of Microbiology, Vol.2(1) 2012: 38-41

Slide drug susceptibility test for the detection of multidrug-resistant tuberculosis in Bangladesh

The present study attempted to comparatively assess and establish a suitable detection method of multidrug-resistant tuberculosis (MDR-TB) from previously treated TB cases in Bangladesh. Of 130 Zeihl-Neelsen smear-positive fresh sputum specimens, 112 samples were found to contain viable bacilli as visualized under the light-emitting diode fluorescence microscope after fluorescein di-acetate staining, and 109 positive cases were detected through Löwenstein-Jensen culture. The samples were further tested to survey the drug resistance both by slide drug susceptibility test (DST) and by conventional DST: 94 MDR-TB cases were detected within 10 days through the slide DST, whereas 82 cases were observed through the conventional DST, requiring about 3 months. Because the rapidity, sensitivity and accuracy of the slide DST method were found to be comparatively satisfactory when compared to the conventional DST method; we recommend the slide DST method as the standard diagnostic tool in perspective of Bangladesh for the detection of MDR-TB.

Study of antimicrobial susceptibility of clinically significant microorganisms isolated from selected areas of Dhaka, Bangladesh

Objective: Pathogenic resistance against antibiotics is substantially mounting in the developing countries including Bangladesh. Present study thus attempted to obtain the baseline information on such resistance among the community people coming to the local dispensaries around the city of Dhaka for treatment. Materials and Methods: A total of 2,700 clinical specimens were examined for the presence of Gram positive and Gram negative pathogens. Antibiotic susceptibility tests of the isolates were carried out. Extended spectrum b- lactamase (ESBL) activity, and the presence of methicillin resistant Staphylococcus aureus (MRSA) and S. epidermidis (MRSE) were also detected. Results: Escherichia coli were most prevalent (45.5%) among 1044 pathogenic bacteria isolated from 2,700 samples. E. coli predominated urine, pus, wound swab, blood, high vaginal swab (HVS) and sputum specimens, and exhibited the highest frequency of ESBL activity (35%). Prevalence of Klebsiella spp. and S. aureus among the clinical specimens were 11.5% and 9.86%, respectively. Most of the Gram negative bacilli were found resistant against ciprofloxacin (5 mg), tetracycline (30 mg) and cotrimoxazole (25 mg). Majority of Pseudomonas spp. were found resistant against most of the commonly used antibiotics. Interestingly, around half of the S. aureus isolates were observed to be methicillin resistant, but not vancomycin resistant. Conclusion: Overall, such a revelation of increased antibiotic resistance demands for restrictive and appropriate antibiotic usage in accordance with the updated antibiotic prescribing policy in Bangladesh. DOI: http://dx.doi.org/10.3329/bjms.v12i1.13351 Bangladesh Journal of Medical Science Vol. 12 No. 01 January’13 pp.34-42

Use of fluorescein diacetate (FDA) staining to detect viable Mycobacterium tuberculosis

Objective: Drug resistant tuberculosis has long been a common problem prevailing in developing countries including Bangladesh. Present study focused on the rapid identification of live Mycobacterium tuberculosis among treatment failure cases.Materials and Methods: Sputum samples from a total of 100 category-I and category-II treatment failure cases, assumed as multidrug resistant tuberculosis, were studied through fluorescein diacetate (FDA) staining under light emitting diode (LED) fluorescence microscope. Considering culture method as gold standard, we also compared the results of FDA staining with that of auramine O staining.Results: A total of 85% acid-fast bacilli were detected by FDA staining, 82% by auramine O staining and a total of 85% isolates were detected in Lowenstein-Jensen (LJ) culture. The sensitivity of FDA staining (96.47%) was estimated to be slightly higher than that of auramine O staining (91.76%). Moreover,76.47% cases were detected as multidrug resistant tuberculosis (MDR-TB). Conclusion: Taken together, FDA staining method has been proposed to be appropriate for the rapid diagnosis of drug resistant tuberculosis. DOI: http://dx.doi.org/10.3329/bjms.v11i4.12605 Bangladesh Journal of Medical Science Vol. 11 No. 04 Oct’12

Comparisons among the diagnostic methods used for the detection of extra-pulmonary tuberculosis in Bangladesh

The present study was an attempt to establish a suitable method for the effective diagnosis of extra-pulmonary tuberculosis in Bangladesh. In this regard, detection of Mycobacterium tuberculosis from 390 different extra-pulmonary specimens was performed by Bright-Field microscopy, light-emitting diode fluorescence microscopy and Lowenstein-Jensen culture methods, followed by an extensive comparison among these methods. M. tuberculosis was detected in 53 cases through the conventional Lowenstein-Jensen culture method; 49 cases were detected under Bright-Field microscope, whereas the light-emitting diode fluorescence microscopy detected 64 cases. Out of 53 culture-positive isolates, 12 were found to be multi-drug resistant. Light-emitting diode fluorescence microscopy was found to be more sensitive and effective than both the Bright-Field microscopy and the Lowenstein-Jensen culture methods. Incidentally, light-emitting diode fluorescence microscopy appeared imperative to detecting the multi-drug resistant tuberculosis.

Detection of Virulence Potential of Diarrhoeagenic Escherichia coli Isolated from Surface Water of Rivers Surrounding Dhaka City

A total of 21 isolates were included randomly on the basis of their initial identification by the appearance of metallic sheen and from the biochemical traits to detect virulent markers of diarrhoeagenic E. Coli isolated from surface water. The antibiotic susceptibility pattern of the isolates were determined against six most commonly used antibiotics. About 52% of the isolates showed resistance to at least one of the antibiotics. About 38% of the isolates were resistant to more than one antibiotics. However, all the isolates were sensitive to gentamicin (CN). Among the 21 isolates, a total of 5 randomly selected isolates were examined for the detection of virulent genes (elt, est and stx) by PCR based method. Among the 5 tested isolates, 3 harbored the gene stx encoding Shiga toxin (Stx) and 2 to elt encoding heat-labile enterotoxin (LT). None of the isolates contained est encoding heat-stable enterotoxin (ST). Data revealed that as the virulent marker genes  were detected, diarrhoeagenic E. coli strains present in the surface water would become a major public health concern. DOI: http://dx.doi.org/10.3329/jbas.v36i1.10927 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 1, 109-121, 2012

Oxidative stress as a trigger for growth phase-specific sigmaE-dependent cell lysis in Escherichia coli

Sigma(E), encoded by rpoE, causes lysis of viable but nonculturable (VBNC) cells at the early stationary phase in Escherichia coli. However, the factors that trigger this lysis phenomenon remain unidentified. In this study, we found that the defective strain of katE, encoding catalase, exhibited a sigma(E)-dependent cell lysis phenotype, showing a decrease in turbidity of cell culture and an increase in accumulation of proteins in the culture medium as well as an increase in rpoE expression. The level of intracellular reactive oxygen species became maximal at the transition period from exponential to stationary phases, and VBNC cells gradually increased after that period. In the wild-type strain, both sodA, encoding superoxide dismutase, and katE plasmid clones almost completely suppressed cell lysis, largely reduced reactive oxygen species, and substantially increased culturable cells. Consistent results were obtained in a defective strain of rseA, encoding an anti-sigma(E), in which sigma(E) is constitutively expressed. These results suggest that oxidative stress is a major factor responsible for VBNC cell formation and cell lysis at the early stationary phase. Therefore, we assume that oxidative stress that has accumulated in the transition period gives rise to VBNC cells, which are in turn lysed by a sigma(E)-dependent process.