Antimicrobial resistance pattern of anaerobic bacteria causing lower respiratory tract infections

BACKGROUND

Anaerobes are normal flora of the human body. However, they can cause serious infections in humans. Anaerobic bacteria are known to cause respiratory infections like pneumonia and acute exacerbation of chronic lower airway infections. These are often missed due to the complexity of their isolation and identification. Hence, this study aimed to study anaerobes causing respiratory tract infections and determine their antibiotic susceptibility.

MATERIALS & METHODS

Clinical specimens such as bronchial aspirates and pleural aspirates collected from patients with respiratory diseases attending Vallabhbhai Patel Chest Institute were processed, the anaerobes isolated were identified, and their susceptibilities to various groups of antimicrobials were studied using standard microbiological methods.

RESULTS

Three hundred and fourteen patients were included in the study, 154 males and 160 females. Of these 314 patients, 148 (47%) yielded anaerobes in their clinical samples. Seventy patients had more than one type of anaerobic organism. Hence, 235 isolates were recovered belonging to as many as 17 genera. The MIC of seven antibiotics on 154 isolates was tested. The isolates belonged mostly to the genera Bacteroides, Prevotella, Veillonella, and Actinomyces. Variable resistance was observed to most classes of antibiotics by many genera.

CONCLUSIONS

Metronidazole is commonly used against anaerobes, but the study showed that the isolates were 20-30% resistant to the antibiotic. Starting this as an empirical therapy might lead to treatment failure.

Relationship between tooth type and material used in the construction of endocrowns and fracture force values: a systematic review

OBJECTIVE

The aim of this study was to summarize the results of the endocrown (EC) studies that compared tooth preparation designs, tooth types, and ceramic material types in relation to fracture force values.

MATERIALS AND METHODS

A full literature search was conducted in Web of Science, PubMed/Medline, EMBASE, Scopus, Cochrane Library, Google Scholar, and ProQuest electronic databases. The following keywords: Endocrown [(molar(s)) or (premolar(s) or (posterior teeth)] and Ceramic materials as (Lithium disilicate glass-ceramic; Zirconia; Lava Ultimate) and (fracture strength) or (fatigue) were used. Articles were manually searched utilizing their reference lists. Study selection was not restricted or limited to the time of publication, type of tested tooth, ceramic material, and EC design.

RESULTS

A total of 34 laboratory studies published between 2008 and 2023 were included in this systemic review. Twelve studies were published in the last 3 years, the mandibular molar was examined by 14 studies, and premolars in both arches were investigated, followed by premolars in both arches. Lithium disilicate glass-ceramic (LDGC) was the most used material for EC testing, followed by LAVA Ultimate and zirconia materials. The EC design with a 2 mm extension inside the pulp (14 studies) was the most used. Fracture forces of maxillary molars or premolars were nearly equal and lower than those of mandibular molars. Differences among the fracture forces of the tested ceramic materials were marginal. EC with 2 mm deep inside the pulp showed the highest fracture force.

CONCLUSIONS

Mandibular EC molars showed the highest fracture forces, followed by maxillary premolars and molars. No differences among the EC materials in the 2- and 4-mm pulpal extension designs were found, which had higher fracture forces than other designs.

Transitions from pediatric to adult rheumatology care for juvenile idiopathic arthritis: a patient led qualitative study

Background

Juvenile idiopathic arthritis (JIA) is a childhood autoimmune disease that causes swelling and pain in at least one joint. Young people with JIA experience symptoms that persist into adulthood, and thus will undergo a transition including the o transfer of care from a pediatric rheumatologist an adult rheumatologist. Missing from the literature is research that centres the transition experience of young people with JIA in Canada. This goal of this patient-led research was to explore the experience young people with JIA through the process of transition.

Methods

Qualitative study using the Patient and Community Engaged Research (PaCER) approach. Trained patient-researchers conducted three focus groups using the Set, Collect and Reflect PaCER process. Participants, recruited via purposive and snowball sampling using research/personal networks and social media, were young people with JIA in Canada between 18 and 28 years who had experienced with the process of transition to adult care. Recordings were transcribed verbatim. Patient researchers individually coded overlapping sections of the data, and thematic analysis was conducted.

Results

In total, nine individuals participated in one or more focus groups. Three themes were identified, with sub-themes: preparedness for transition (readiness for the transfer of care, developing self-advocacy skills), continuity and breadth of care (changing relationships, culture shock, new responsibilities), need for support (social support, mental health support, and ongoing support needs – beyond the transfer of care. Peer support was a connecting concept in the support sub-themes. Transition was more than a change in primary physician but also a change in the care model and breadth of care provided, which was challenging for young people especially if they had insufficient information.

Conclusions

Transition from pediatric to adult care in rheumatology is a significant period for young people living with JIA, and this patient-led study provided insight into the experience from the perspective of young people with JIA which is critical to informing the development of supports for patients through the process. Patients, caregivers, pediatric and adult rheumatologists and members of the multi-disciplinary care team need to collaborate in terms of resources preparing for transfer, and support throughout the transition process to ensure a successful transition process.

Calcium Dynamics Regulate Protective Responses and Growth of Staphylococcus aureus in Macrophages

Staphylococcus aureus (S. aureus) is a gram-positive bacteria, which causes various fatal respiratory infections including pneumonia. The emergence of Methicillin-Resistance Staphylococcus aureus (MRSA) demands a thorough understanding of host-pathogen interactions. Here we report the role of calcium in regulating defence responses of S. aureus in macrophages. Regulating calcium fluxes in cells by different routes differentially governs the expression of T cell costimulatory molecule CD80 and Th1 promoting IL-12 receptor. Inhibiting calcium influx from extracellular medium increased expression of IFN-γ and IL-10 while blocking calcium release from the intracellular stores inhibited TGF-β levels. Blocking voltage-gated calcium channels (VGCC) inhibited the expression of multiple cytokines. While VGCC regulated the expression of apoptosis protein Bax, extracellular calcium-regulated the expression of Cytochrome-C. Similarly, VGCC regulated the expression of autophagy initiator Beclin-1. Blocking VGCC or calcium release from intracellular stores promoted phagosome-lysosome fusion, while activating VGCC inhibited phagosomelysosome fusion. Finally, calcium homeostasis regulated intracellular growth of Staphylococcus, although using different mechanisms. While blocking extracellular calcium influx seems to rely on IFN-γ and IL-12Rβ receptor mediated reduction in bacterial survival, blocking either intracellular calcium release or via VGCC route seem to rely on enhanced autophagy mediated reduction of intracellular bacterial survival. These results point to fine-tuning of defence responses by routes of calcium homeostasis.

Oral anticoagulant monotherapy compared to oral anticoagulant plus single anti-platelet therapy in stable ischemic heart disease with atrial fibrillation: a meta-analysis

Introduction

Evidence for antithrombotic therapy regimen in patients with concurrent stable ischemic heart disease (SIHD) and atrial fibrillation (AF) is not well established. The ideal regimen needs to been balanced to prevent thrombotic and embolic events, without increasing the risk of bleeding tendencies. Two randomized control trials have been published studying oral anticoagulant monotherapy (OAC) as compared to oral anticoagulant plus single antiplatelet therapy (OAC+SAPT), of which one trial was terminated prematurely and was underpowered.

Purpose

We performed a meta-analysis of RCTs and observational studies comparing OAC monotherapy to OAC+ SAPT in SIDH patients with AF.

Methods

We performed a systematic search of the PubMed, EMBASE and Cochrane databases to identify relevant articles. The database search was performed from the inception of the databases to January 2020. Inclusion criteria were RCTs and observation studies comparing OAC to OAC+SAPT in SIDH patients with AF and reporting time to event outcomes of major bleeding or cardiovascular mortality. The definition of major bleeding as per the definition provided by individual studies. Two authors independently performed data extraction to check for reproducibility. We used inverse variance method with random effect model to calculate hazard ratio (HR) with 95% confidence interval (CI). Statistical heterogeneity was calculated using Higgins I2 statistics. All statistical analysis was performed using RevMan Version 5.3 (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014).

Results

Seven studies (2 RCTs and 5 observational studies) were included in the final analysis. OAC+ SAPT as compared to OAC monotherapy in patients with SIHD and AF was associated with a higher incidence of major bleeding [HR: 1.59, 95% CI: 1.36–1.85, P value<0.05, I2: 0%] [Figure 1, Panel A]. OAC+SPT as compared to OAC monotherapy was associated with similar incidence of cardiovascular mortality [HR: 1.07, 95% CI: 0.86–1.33, P value= 0.55, I2: 32%] [Figure 1, Panel B]. There was no statistical heterogeneity associated with either pooled estimates.

Conclusion

OAC monotherapy as compared to OAC+SAPT in patients with SIHD and AF was associated with a lower incidence of major bleeding and similar incidence of cardiovascular mortality.

Figure 1

Funding Acknowledgement

Type of funding source: None

Impella versus intra-aortic balloon pump in cardiogenic shock: a meta-analysis assessing 30-days mortality

Introduction

Cardiogenic shock is linked with eminent morbidity and mortality despite advances in treatment modality. Adjuvant treatment modalities to provide mechanical haemodynamic support in the form of intra-aortic balloon pump (IABP) or Impella are being used among patients with cardiogenic shock. The Impella prunes left ventricular preload, whereas, IABP persuades after load reduction and both contribute to improved cardiac output. A few underpowered randomised control trials (RCTs) and observational studies compared short term mortality benefit of Impella juxtaposed to IABP among patients with cardiogenic shock.

Purpose

A meta-analysis of RCTs and observational studies researching the short-term mortality in cardiogenic shock comparing Impella to IABP was executed.

Methods

The databases PubMed, EMBASE and Cochrane were searched systematically to identify relevant RCTs and observational studies contrasting Impella to IABP and reporting 30-days mortality as outcomes. The search terms used were “Impella”, “IAPB”, “intra-aortic balloon pump” and all word variations were utilised. The search was conducted from the debut of the databases up to January 2020. Two reviewers independently and in tandem performed data screening and extraction from identified articles. Inverse variance method with Paule-Mandel estimator for tau2 and Hartung-Knapp adjustment was used to calculate Risk Ratio with 95% confidence interval. Heterogeneity was assessed using I2 statistics. Furthermore, we calculated the 95% predictive interval for the pooled estimate. All statistical analysis for this meta-analysis was carried out using R statistical software version 3.6.2 using the package meta ( ). Additionally, Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria were used to assess the certainty of evidence.

Results

Five studies constituting 728 patients were included in the final analysis. Two were RCTs (ISAR-SHOCK trial and IMPRESS in Severe Shock trial), one study was a propensity score matched observational study and two were unmatched observational studies. There was no difference in the risk of 30-days mortality in patients treated with Impella as compared to IABP [Risk Ratio: 0.97, 95% confidence interval: 0.66–1.41, I2: 32%]. To account for the heterogeneity, we calculated 95% predictive interval: 0.46–2.02. Thus, very low certainty of evidence concluded no difference in the risk of 30-days mortality among cardiogenic shock patients treated with Impella in opposition to IABP.

Conclusion

This meta-analysis comparing Impella juxtaposed with IABP demonstrated no difference in the risk of 30-days mortality among patients with cardiogenic shock.

30-days Mortality

Funding Acknowledgement

Type of funding source: None

Mortality benefit with remote ischemic preconditioning in STEMI: a frequentist and Bayesian meta-analysis of randomized controlled trials

Introduction

Myocardial infarction related morbidity and mortality remains substantial despite perpetual improvement in patient care. Remote ischemic preconditioning among patients with myocardial infarction has exhibited to improve surrogate markers of ischemia. However, its effect on all-cause mortality is not well established.

Purpose

An updated frequentist and Bayesian meta-analysis of randomised control trials [RCTs] investigating remote ischemic preconditioning among patients with ST segment elevation myocardial infarction [STEMI] and its effect on all-cause mortality.

Methods

A systematic search across PubMed, EMBASE and Cochrane databases was performed. The inclusion criteria was RCTs comparing remote ischemic preconditioning with standard treatment juxtaposed to standard treatment alone among patients with STEMI and reporting all-cause mortality. Data extraction was carried out by two independent authors and looked for reproducibility. Inverse variance method with Paule-Mandel estimator for tau2 and Hartung-Knapp adjustment was used to calculate Risk Ratio with 95% confidence interval. Heterogeneity was assessed using I2 statistics. We estimated the robustness of our pooled effect size using Bayesian meta-analysis. A weakly informative prior [normal (0, 1) for intercept and uniform (0, 2) for standard deviation] and 20000 iterations [10000 warm-up + 10000 sampling] were used for Bayesian meta-analysis. We used meta ( ) and brm ( ) package in R for frequentist and Bayesian meta-analysis, respectively. All statistical analysis was carried out using R statistical software version 3.6.2. The certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluations (GRADE).

Results

Five RCTs comprising a total of 6043 patients [3010 intervention and 3033 controls] were included in the final analysis. The largest included RCT was the CONDI-2/ERIC-PPCI 2019 trial. Remote ischemic preconditioning among patients with STEMI had no effect on all-cause mortality at follow-up [RR=0.70, 95% confidence interval = 0.26–1.87, I2=60%] [Figure 1, Panel A]. Similar results were obtained from hierarchical Bayesian meta-analysis [RR=0.55, 95% credibility interval = 0.23–1.38] [Figure 1, Panel B]. Low certainty of evidence as per GARDE, reports no benefit of remote ischemic preconditioning in reducing the risk of all-cause mortality in STEMI.

Conclusion

Remote ischemic preconditioning among patients with STEMI has no effect on all-cause mortality at follow-up.

Figure 1

Funding Acknowledgement

Type of funding source: None

Food safety: a linchpin of One Health

In 2015, the United Nations General Assembly agreed upon 17 global Sustainable Development Goals. The first of these is: 'End poverty in all its forms everywhere'. The second is to: 'End hunger, achieve food security and improved nutrition, and promote sustainable agriculture'. Food safety is a global priority, since every global citizen has the right to have access to safe and nutritious food. Safe food contributes to people's health and productivity, as well as providing a strong foundation for development and poverty alleviation. Every year, numerous people are affected by foodborne illnesses in developed countries, while widespread illness is even more likely in developing countries. Among society's major concerns are the health risks posed by microbial pathogens and chemicals in food. A One Health approach is crucial to achieving the global goal of food safety and security for all and will improve health outcomes for every citizen.

Nipah virus infection: A review

Nipah virus (NiV) is an emerging bat-borne pathogen. It was first identified 20 years ago in Malaysia and has since caused outbreaks in other parts of South and Southeast Asia. It causes severe neurological and respiratory disease which is highly lethal. It is highly infectious and spreads in the community through infected animals or other infected people. Different strains of the virus show differing clinical and epidemiological features. Rapid diagnosis and implementation of infection control measures are essential to contain outbreaks. A number of serological and molecular diagnostic techniques have been developed for diagnosis and surveillance. Difficulties in diagnosis and management arise when a new area is affected. The high mortality associated with infection and the possibility of spread to new areas has underscored the need for effective management and control. However, no effective treatment or prophylaxis is readily available, though several approaches show promise. Given the common chains of transmission from bats to humans, a One Health approach is necessary for the prevention and control of NiV infection.

Corynebacterium striatum: an emerging respiratory pathogen

INTRODUCTION

Corynebacterium spp. are primarily considered normal flora and dismissed when isolated from clinical specimens. In recent years, Corynebacterium striatum has emerged as a multi-drug resistant human pathogen which can cause nosocomial outbreaks. The organism has infrequently been noted to cause respiratory infections. A retrospective study was conducted to identify the clinical and microbiological features of respiratory infection by Corynebacterium striatum.

METHODOLOGY

C. striatum isolates from clinical and surveillance samples were tested for susceptibility to antimicrobials and typed by Random Amplification of Polymorphic DNA (RAPD). Clinical data was obtained through a retrospective review of records.

RESULTS

15 isolates from clinical and surveillance samples of 11 hospitalised patients were included. The patients suffered from either an exacerbation of COPD (n = 9) or pneumonia (n = 2). The isolates were all multi-drug resistant. RAPD typing found no evidence of an outbreak/ transmission between patients.

CONCLUSIONS

Corynebacterium spp. must be considered potential pathogens. Suspicious isolates should be identified to the species level since Corynebacterium striatum is often multi-drug resistant.

Serum cortisol level and survival rate of juvenile Epinephelus fuscoguttatus following exposure to different salinities

Background and Aim:

Brown-marbled grouper Epinephelus fuscoguttatus is a premium marine food fish with high demand in Asia. In fish, stress due to environmental changes such as fluctuations in the salinity can result in increased cortisol level. Stress in fish increases susceptibility to diseases ultimately resulting in death. Therefore, the aim of this study was to investigate the salinity tolerance of E. fuscoguttatus and their survival in lower salinities.

Materials and Methods:

In this study, grouper juveniles (92.43±standard error of the mean 0.51 mm) maintained in 31 ppt seawater were transferred into five tanks with seawater diluted to 25, 20, 15, 10, and 5 ppt. The salinity of the control group was not changed and was maintained at 31 ppt. Serum cortisol was measured using ELISA at 0, 30, 60, and 120 min after the fish were transferred to the different concentrations of salinity.

Results:

The survival percentage was recorded for 14 days following the transfer and the results revealed that serum cortisol of fish in a high change in salinity (15, 10, and 5 ppt) was significantly higher than the control group immediately after exposure. At the high salinity change, the cortisol levels gradually decrease at 30 min and 60 min, until no difference in cortisol concentration was observed at 120 min. No mortality was observed in fish exposed to low salinity change (25 and 20 ppt) while in higher salinity change (5 ppt), the survival percentage was 50%.

Conclusion:

The study revealed that the serum cortisol concentration was high initially and continues to decrease to resting cortisol level at 120 min indicating that cortisol hormone is released following acute stress as a primary response in grouper juveniles.

Protective immunity of recombinant LipL21 and I-LipL21 against Leptospira interrogans serovar Autumnalis N2 infection

INTRODUCTION

Leptospirosis is a zoonotic disease caused by the spirochete of genus Leptospira with widespread distribution in tropical, subtropical and temperate zones. Leptospirosis is often confused with other febrile illnesses including jaundice, dengue, and malaria. Generally, the disease is often underdiagnosed or misdiagnosed. Though leptospirosis is curable with antibiotic treatment, the laboratory diagnosis of the disease is specialized and open to interpretation with multiple kits available to detect the different serological markers of Leptospira. Moreover, when leptospirosis is misdiagnosed, the disease can lead to multi-organ failure and may have fatal effects. There is a need for strategies to develop vaccines and prevent leptospirosis. In the present study, the immunogenic potential of leptospiral recombinant protein LipL21 (rLipL21) and its truncated form I-LipL21 (rI-LipL21) was evaluated.

METHODOLOGY

The recombinant proteins were established in cyclophosphamide treated BALB/c mice model infected with L. interrogans serovar Autumnalis strain N2.

RESULTS

The vaccination study showed 66% and 83% survivability among mice immunized with rLipL21 and rI-LipL21 respectively and post-challenge with leptospiral strain N2 compared to control groups that showed 100% lethality. Additionally, a significant increase in antibody levels and cytokine levels (TNF-a, IFN-γ and IL-10) was observed evidencing a marked stimulation of both humoral and cell-mediated immune response in mice immunized with rLipL21/rI-LipL21 compared to whole cell leptospiral lysate (WCL).

CONCLUSIONS

This study evidenced protective immunization against leptospirosis with rLipL21 and rI-LipL21 recombinant proteins and are potential candidates for the development of leptospiral vaccine.

Similar virulence properties of infection and colonization associated Pseudomonas aeruginosa

PURPOSE

Pseudomonas aeruginosa is one of the agents that are commonly implicated in nosocomial infections. However, it is also present as a commensal in various body sites of healthy persons, making the diagnosis of infection by culture difficult. A number of virulence factors expressed by the organism have been implicated in its pathogenicity. We undertook this study to identify the host and organism factors associated with infection.

METHODOLOGY

Pathogenic, colonizing and environmental isolates were tested for apr, lasB, the T3SS effector exoenzymes (exoS, exoT, exoU and exoY) and toxA genes, biofilm production and antimicrobial susceptibility. The isolates were further typed by RAPD.

RESULTS

Eighty-seven isolates from 61 patients, including 11 environmental isolates, were obtained. None of the virulence factors were found to be significantly associated with infection, and nor was the antimicrobial susceptibility. The presence of the exoU gene and infection by MDR strains correlated significantly with the duration of hospital stay. Positivity for exoS and exoU genes was found to be strongly correlated with multi-drug resistance. exoU positivity correlated strongly with fluoroquinolone resistance. Sinks in the ward and intensive care unit were found to be a niche for XDR P. aeruginosa. Eighty-five isolates were typeable using the ERIC2 primer, showing 71 distinct RAPD patterns with >15 % difference in UPGMA-generated dice coefficients.

CONCLUSIONS

exoU positivity is associated with severe disease, as evidenced by the longer duration of hospital stay of these patients. However, the presence of virulence factors or multi-drug resistance in the cultured strain should not prompt the administration of anti-pseudomonal chemotherapy.

Exacerbation of bronchiectasis by Pseudomonas monteilii: a case report

BACKGROUND

Pseudomonas spp are important opportunistic and nosocomial pathogens. One such species is Pseudomonas monteilii (P. monteilii). It has been described as an environmental contaminant and potential pathogen. We identified this organism as the causative agent of an exacerbation of bronchiectasis and an environmental contaminant in our hospital on two separate occasions.

CASE PRESENTATION

P. monteilii was the cause of an exacerbation of bronchiectasis in a 30-year-old HIV negative male. Patient presented with cough with sputum production and exertional dyspnea. The isolate was recovered from a sputum sample in significant counts and definitively identified by Matrix-Assisted Laser Desorption/Ionisation- Time of Flight Mass Spectrometry (MALDI-TOF MS). He was treated with piperacillin-tazobactam and recovered clinically and microbiologically. Another two isolates of the organism were contaminants from the hospital environment. The three isolates were susceptible to all tested antibiotics. Typing by Random amplification of polymorphic DNA (RAPD) found no clonal relationship between them.

CONCLUSIONS

Less common species of Pseudomonas need to be identified accurately. This organism is identified by commonly used phenotypic systems as P. putida which may have contributed to a lower reported prevalence. P. monteilii is a known environmental contaminant and must also be considered as a potential pathogen, particularly in patients with chronic lung disease.

Enhancement of lipid production in two marine microalgae under different levels of nitrogen and phosphorus deficiency

Microalgae are important food sources for aquaculture animals. Among the different factors which influence the biochemical composition of microalgae, nitrogen and phosphorus are two of the most important nutrient sources for growth and development. The present study aimed to assess the effects of nitrogen and phosphorus deficiency on lipid production of Chlorella sp. and Chaetoceros calcitrans. Early stationary phase culture of these species were exposed to different stress levels of nitrogen and phosphorus (25%, 50% and 75% of the full NO(3)-N and PO(4)-P concentration in the Conway media), and solvent extraction and gas-liquid chromatography methods were performed for analysis of lipid and fatty acid composition. The results revealed that lipid production in these two species significantly increased (P<0.05) as nitrogen and phosphorus decreased. The fatty acid proportion remained unaffected under nitrogen deficiency, while phosphorus limitation resulted in a decrease of saturated fatty acids and promoted a higher content of omega-3 fatty acids in these species. The protein and carbohydrate levels were also altered under limited nutrients. Therefore, these conditions could be used for enhanced lipid production in microalgae for aquaculture and other industrial applications.

Phenolic content and antioxidant activity of Tetraselmis tetrathele (West) Butcher 1959 cultured in annular photobioreactor

Tetraselmis tetrathele (West) Butcher is an important microalgae due to its high antioxidant content and other bioactive compounds such as flavonoids and polyphenols. Therefore, it has potential as a suitable raw ingredient for various product developments in aquaculture, food and nutraceutical industries. The antioxidant activity of T. tetrathele (UPMC-A0007) was determined by culturing in f/2 and Conway media for 56 days in 120 l annular photobioreactors. The total phenolic (TPC) and antioxidant contents of T. tetrathele were determined six times during different phases of the culture period. The antioxidant activities of T. tetrathele's crude extract were determined by diphenylpicrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Two groups of cells based on size; small sized-cells (3.0-5.0?10-11g cell(-1)) and big sized-cells (5.5-8.0?10(-11) g cell(-1)) were observed in the f/2 media. Small sized-group showed 1.6 times higher total phenolic content (2.99?0.14 mg GAEg(-1)) than big sized-cells. These results suggest that T. tetrathele is a potential antioxidant source and effective antioxidant production can be achieved by controlling the cell size in their culturing process.

Sustainable aquaculture of Asian arowana--a review

Asian arowana, Scleropages formosus is a highly valued aquarium fish in the world, particularly in Asian countries, and has been listed as one of the most highly endangered species. This is a freshwater, carnivorous, fairly large mouth breeding fish belonging to the family Osteoglossidae. Arowana can be found in different colour varieties such as green, red, silver and golden. Among these varieties, Malaysian golden is the most valuable fish and is endemic to the Krian riverine system, Malaysia. However, overexploitation, habitat change and pollution have caused a serious decline of this arowana variety. Recently, arowana aquaculture industry is expanding rapidly in Southeast Asian countries. However, difficulties in an accurate differentiation of sex and strains, causing imbalanced stocking ratios for optimum spawning, remain major obstacles in maximizing arowana production. In addition, problems in sustainable water sources of suitable quality and prevention of diseases need to be addressed. Recirculating aquaculture system (RAS) and bioremediation are two possible technologies that could be used to minimize pollution and ensure adequate high-quality water for arowana culture. In addition, the application of appropriate molecular markers for sex and strain identification is also an important strategy required for the improvement of captive breeding. This review discusses several issues such as the importance of arowana as an aquarium fish, its market demand, current problems in the arowana aquaculture industry and the possible technologies to enhance reproductive capacity and increase culture production. ?

Phenotypic and molecular characterization of clinical isolates of Acinetobacter baumannii isolated from Delhi, India

Background

Acinetobacter has gained importance as a multi-drug resistant and hence a difficult to treat pathogen. This study was done to characterize our isolates with respect to drug resistance and presence of beta-lactamases which is a major mechanism of resistance and to type using RAPD and MLST so that comparison of our clones can be made with the existing international clones.

Methods

100 isolates recovered from clinical samples from two hospitals in Delhi were tested for their susceptibility against major groups of antimicrobials. The resistant isolates were screened and confirmed phenotypically for presence of ESBL, MBL and AmpC and MBLs also by PCR. The isolates were typed by RAPD and MLST.

Results

Out of the 100 isolates, 91, 78 and 2 % were MDR, XDR and PDR respectively. 97, 100 and 85 were screen positive for ESBL, AmpC and MBL respectively. Of these, 38.1 % were confirmed phenotypically to produce ESBL, 99 % produced AmpC and 29.4 % produced MBL comprising of GIM, VIM, SIM and IMP. MLST showed known STs 110, 188, 146, 69, 103, 108 and 194. Eight new STs were encountered. The RAPD showed a high degree of genetic variability among the isolates.

Conclusion

Majority of our isolates were MDR, producing one or more types of beta-lactamases. We encountered drug resistant international clones by MLST which are found in other continents there by confirming their spread to Indian sub continent. No data on ST types of other Indian isolates is available in the MLST database and hence comparison is not possible.

Detection and molecular characterization of infectious spleen and kidney necrosis virus from major ornamental fish breeding states in Peninsular Malaysia

'Gold standard' OIE reference PCR assay was utilized to detect the presence of infectious spleen and kidney necrosis virus (ISKNV) in freshwater ornamental fish from Malaysia. From total of 210 ornamental fish samples representing 14 species, ISKNV was detected in 36 samples representing 5 fish species. All positive cases did not show any clinical signs of ISKNV. Three restriction enzymes analyses showed that the fish were infected by identical strains of the same virus species within Megalocytivirus genus. Major capsid protein (MCP) genes of 10 ISKNV strains were sequenced and compared with 9 other reference nucleotide sequences acquired from GenBank. Sequence analysis of MCP gene showed that all strains detected in this study were closely related to the reference ISKNV with nucleotide sequence identity that was ranging from 99.8% to 100%. In addition, phylogenetic analysis of MCP gene revealed that viruses from genus Megalocytivirus can be divided into three genotypes: genotype 1 include reference ISKNV and all other strains that were detected in this study, genotype 2 include viruses closely related to red sea bream iridovirus (RSIV), and genotype 3 include viruses closely related turbot reddish body iridovirus (TRBIV).

Multi-locus sequence types of Acinetobacter baumanii clinical isolates from India

This item has no abstract. Follow the links below to access the full text.

Characterization of Streptococcus pneumoniae isolates from India with special reference to their sequence types

INTRODUCTION

Streptococcus pneumoniae is a major cause of mortality and morbidity in young children and the elderly. In the present study we evaluated antimicrobial susceptibilities, serotypes, and sequence types of pneumococcal isolates recovered in New Delhi, India.

METHODOLOGY

A total of 126 clinical isolates of Streptococcus pneumoniae were investigated. They were subjected to disk diffusion susceptibility testing, broth microdilution testing, serotyping and multilocus sequence typing.

RESULTS

Broth microdilution assay showed that 5%, 20% and 23% of the isolates exhibited resistance to penicillin, erythromycin and ciprofloxacin, respectively. Serotypes19, 1 and 6 were more frequently isolated. Thirty per cent of the strains were comprised of serotypes 1, 3, 5, 19A and 7F, which are not included in the seven-valent vaccine. Fifty-nine isolates were typed using multilocus sequence typing. Thirty new sequence types were encountered in this study. Only one clonal complex with 4 isolates was seen; 11 clonal complexes and 96 sequence types (STs) were observed among 115 Indian isolates. Only 18 of the 96 STs were found globally, of which only 4 STs were found in many countries with larger numbers.

CONCLUSIONS

This study identifies the non-vaccine serotypes of Streptococcus pneumoniae circulating in India. It is important that an appropriate vaccine which covers all serotypes is used in the region.

Large-scale culture of a tropical marine microalga Chaetoceros calcitrans (Paulsen) Takano 1968 at different temperatures using annular photobioreactors

Outdoor mass culture of microalgae in the tropical area is important to minimize its production cost. This study evaluates the growth of Chaetoceros calcitrans in 120 L annular photobioreactors at indoor temperature (Treatment I, 25 +/- 2 degrees C) and outdoor tropical ambient temperature, (Treatment II, 30 +/- 6 degrees C). Each treatment was done in duplicates. For both treatments, C. calcitrans was first grown in starter columns of 10 L capacity for a period of 7 days at 25 +/- 2 degrees C. After 7 days, the 9 L culture was transferred to the annular photobioreactors and subsequently brought to a final volume of 100 L by adding 20 L fresh medium every 5 days. There was no significant difference (p > 0.05) in the dry weight of microalgae grown in natural light and those grown indoor. The results suggest that C. calcitrans can be grown in outdoor conditions, hence, saving time and microalgae production cost for the larviculture industry.

TaqMan real-time PCR assay for relative quantification of white spot syndrome virus infection in Penaeus monodon Fabricius exposed to ammonia

White spot disease is caused by a highly virulent pathogen, the white spot syndrome virus (WSSV). The disease is usually triggered by changes in environmental parameters causing severe losses to the shrimp industry. This study was undertaken to quantify the relative WSSV load in shrimp exposed to ammonia, using a TaqMan-based real-time PCR, and their subsequent susceptibility to WSSV. Shrimp were exposed to different levels of total ammonia nitrogen (TAN) (8.1, 3.8 and 1.1 mg L⁻¹) for 10 days and challenged with WSSV by feeding WSSV-positive shrimp. WSSV was detected simultaneously in haemolymph, gills and pereopods at four hours post-infection. The TaqMan real-time PCR assay showed a highly dynamic detection limit that spanned over 6 log₁₀ concentrations of DNA and high reproducibility (standard deviation 0.33-1.42) and small correlation of variability (CV) (1.89-3.85%). Shrimp exposed to ammonia had significantly higher (P < 0.01) WSSV load compared to the positive control, which was not exposed to ammonia. Shrimp exposed to 8.1 mg L⁻¹ of TAN had the highest (P < 0.01) WSSV load in all three organs in comparison with those exposed to 3.8 and 1.1 mg L⁻¹ of TAN. However, haemolymph had significantly higher (P < 0.01) viral load compared to the gills and pereopods. Results showed that shrimp exposed to ammonia levels as low as 1.1 mg L⁻¹ (TAN) had increased susceptibility to WSSV.

Role of Mycoplasma pneumoniae infection in acute exacerbations of chronic obstructive pulmonary disease

Eighty per cent of the cases of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) have an infective aetiology, atypical bacteria including Mycoplasma pneumoniae accounting for 5–10 % of these. However, the importance of association of M. pneumoniae with episodes of AECOPD still remains doubtful. The present study was therefore undertaken to delineate the extent of involvement of M. pneumoniae in patients with AECOPD at a referral hospital in Delhi, India. Sputum samples and throat swabs from a total of 100 AECOPD patients attending the Clinical Research Center of Vallabhbhai Patel Chest Institute, Delhi, were collected during a 2-year period (January 2004–June 2006). The samples were investigated for the presence of aerobic bacterial pathogens and M. pneumoniae. Diagnosis of infection with M. pneumoniae was based on culture, serology, direct detection of M. pneumoniae specific antigen and PCR. Bacterial aetiology could be established in 16 of the 100 samples studied. Pseudomonas spp. were recovered from eight cases, Streptococcus pneumoniae from four and Klebsiella spp. from two cases. Acinetobacter sp. and Moraxella catarrhalis were isolated from one case each. Serological evidence of M. pneumoniae infection and/or detection of M. pneumoniae specific antigen were seen in 16 % of the cases. One case with definite evidence of M. pneumoniae infection also had coinfection with Pseudomonas spp. However, no direct evidence of M. pneumoniae infection was found in our study population as defined by culture isolation or PCR. In conclusion, although the serological prevalence of M. pneumoniae infection in our study population was significantly higher than in the control group, there was no direct evidence of it playing a role in AECOPD.

Comparison of four antibiotics with indigenous marine Bacillus spp. in controlling pathogenic bacteria from shrimp and Artemia

Use of antibiotics for the control of bacterial diseases in shrimp culture has caused several adverse impacts to the industry. This has resulted in the search for alternative environment friendly approaches to overcome bacterial infections. This study was conducted to investigate the use of beneficial bacteria as an alternative to antibiotics. Ten pathogenic bacterial species isolated from shrimp, Penaeus monodon, and Artemia cysts were tested for susceptibility to indigenous marine Bacillus subtilis AB65, Bacillus pumilus AB58, Bacillus licheniformis AB69 and compared with oxytetracycline, chloramphenicol, gentamicin and bacitracin, which are common antibiotics used in Asian aquaculture. The Bacillus spp. were isolated from the local marine environment for bioremediation use in shrimp hatcheries and were proven to reduce total ammonium nitrogen. The pathogenic bacterial isolates were 90% susceptible to B. subtilis AB65, 70% susceptible to B. pumilus AB58 and B. licheniformis AB69 and 100% susceptible to oxytetracycline, chloramphenicol and gentamicin but only 40% to bacitracin. Two representative isolates of the vibrio group, Vibrio alginolyticus VaM11 and Vibrio parahaemolyticus VpM1, when tested for competitive exclusion by a common broth method using the marine Bacillus spp., showed decreased viable counts from 10(8) to 10(2) cfu mL(-1). The results suggest that the action of the marine bacteria appears to be significant in protecting the host shrimp against pathogenic bacteria. In addition to the alternative use of antibiotics, the selected marine bacteria had additional bioremediation properties of reducing ammonia.

Chronic community-acquired Acinetobacter pneumonia that responded slowly to rifampicin in the anti-tuberculous regime

Acinetobacter baumannii is a well-known cause of hospital-acquired pneumonia. Occasionally, it can present as an acute community-acquired pneumonia with a fulminant course. However, the occurrence of the chronic form of community-acquired Acinetobacter pneumonia is yet to be highlighted. We describe a 62-year-old, HIV negative, non-diabetic male, who was referred for evaluation of consolidation and cavitation in the apicoposterior segment of the left upper lobe for 4 months. For this, he had received anti-tuberculous therapy, which included rifampicin. On investigation, a diagnosis of chronic community-acquired pneumonia due to Acinetobacter baumannii was made. The steady clinico-radiologic improvement observed was attributed to rifampicin in the anti-tuberculous regime. Subsequently, an aspergilloma formed in the cavity.

A case of excess growth hormone levels

Patients with anorexia nervosa are known to have elevated basal growth hormone levels, which fail to suppress normally during glucose tolerance testing. We describe a case of probable anorexia nervosa initially diagnosed as acromegaly despite a low insulin-like growth factor-1 level and treated with transsphenoidal surgery based on a pituitary microadenoma on magnetic resonance imaging and a lack of suppression of growth hormone levels during glucose tolerance testing. This case highlights, firstly, that pituitary magnetic resonance imaging will suggest a pituitary adenoma in up to 10% of normal individuals. Secondly, that a diagnosis of acromegaly should be made on clinical features as well as growth hormone measurements.

Neonatal Septicaemia: A Hospital Based Study in Eastern Nepal

Septicaemia  is  a  major  cause  of  neonatal  morbidity  and  mortality.  Premature  rupture  of  membrane, premature delivery, low birth weight and hospitalisation of the neonate are some of the predisposing factors, which influence the onset of infection and its outcome.   Depending on the time of onset and the causative factors, a wide variety of organisms are implicated in neonatal septicaemia.   The blood culture takes a minimum of 48 hrs to arrive at a definitive diagnosis. A prompt management of such cases along with empirical antibiotic therapy remains the mainstay of management. Hence, knowledge about the organisms prevalent in a particular hospital and their antibiotic susceptibility pattern is an important prerequisite. The study was carried out at the B.P. Koirala institute of health sciences, a tertiary care hospital, in Eastern Nepal for a period of 3-years from 1998 to 2001. Blood samples from 1567 neonates with suspected septicaemia were cultured using standard microbiological technique. 540 (35%) samples were culture positive. Gram- positive bacteria (74%) were more common than Gram-negative bacteria (27%). Staph aureus   (60%) was the most common bacterial isolate. Resistant to ampicillin was seen but most were susceptible to other antimicrobial  including  gentamicin,  amikacin,  cefotaxime,  and  ciprofloxacin.  Positivity  rate  decreased  in the 3rd  year to 25% as against first two years of 41% and 47% respectively, which was, attributed to training and implementation of various measures of infection control practices. Candida spp was not observed during the period of study. It was concluded that a continuous surveillance of the causative agents and their antimicrobial susceptibility pattern is required to control the infection in the hospital neonatal unit.Key Words: Neonatal septicaemia, Organisms, Antimicrobial susceptibility pattern. 

A study of diarrhoea among children in eastern Nepal with special reference to rotavirus

PURPOSE

To examine the incidence of Rotavirus infection in children below five years of age.

METHODS

Faecal samples from 160 children under five years of age with acute gastroenteritis were collected over a period of one year from July 1999 to June 2000. These were studied for the presence of Rotavirus antigen by enzyme immuno assay (EIA).

RESULTS

Rota antigen could be detected in 62 (38.7%) samples. Co-infection with other parasites or bacterial pathogens in presence of Rota antigen was also demonstrated. Forty one (66.4%) children were admitted for hospital care. Forty two samples positive by EIA were further tested by latex agglutination (LA) to consider introducing this test routinely in clinical laboratory. Although a rapid and convenient test, LA failed to demonstrate antigen in 15 (35.6%) of the samples.

CONCLUSIONS

Rotavirus infection of children in Nepal is reported for the first time. EIA was found to be more sensitive than LA for the detection of Rotavirus antigen in faecal samples.

Descriptive Epidemiology of a Gastroenteritis Out Break in Sunsari District, Nepal

Gastroenteritis (GE) outbreak and cholera epidemics continue to be the major publichealth problems in Nepal. Every year during and immediately after the rainy season,outbreak of GE occurs. In the post monsoon period of 1998 also, outbreak of GEoccurred in a wide area covering several districts in terai region. In this paper, severalepidemiological aspects of the current outbreak are being reported. This study wascarried out in sunsari district. The cases of GE brought to district hospital wereinterviewed by a trained health worker to collect information about the episode andpossible source of infection. Stool samples were collected from the patients and testedfor organisms. On the spot visits were made to collect more information. Water sampleswere also collected and tested in Microbiology laboratory, B. P. Koirala Institute ofHealth Sciences (BPKIHS). There were 947 cases of GE. Among them 55.2% werefemales and 44.8% males patients. The age ranged from 7 months to 86 years withmean age of 22.8 years. There were 8 deaths. Maximum number of cases occurred inthe first fornight of October 1998. Due to prior administration of antibiotics, no growthwas seen in 27 samples. However, 4 samples showed growth of Shigella. Vibrio cholerawas isolated from 2 cases. Eight out of thirteen water samples were found to beunsatisfactory for drinking. The contamination of drinking water source andunhygienic habits were the main causes for such outbreaks. Therefore, it is pertinentthat GE outbreaks may be prevented by simply promoting sanitation and hygienicpractices related to handling of drinking water and defecation.