The COVID-19 and TB syndemic: the way forward

Together, SARS-CoV-2 and M. tuberculosis have killed approximately 5.7 million people worldwide over the past 2 years. The COVID-19 pandemic, and the non-pharmaceutical interventions to mitigate COVID-19 transmission (including social distancing regulations, partial lockdowns and quarantines), have disrupted healthcare services and led to a reallocation of resources to COVID-19 care. There has also been a tragic loss of healthcare workers who succumbed to the disease. This has had consequences for TB services, and the fear of contracting COVID-19 may also have contributed to reduced access to TB services. Altogether, this is projected to have resulted in a 5-year setback in terms of mortality from TB and a 9-year setback in terms of TB detection. In addition, past and present TB disease has been reported to increase both COVID-19 fatality and incidence. Similarly, COVID-19 may adversely affect TB outcomes. From a more positive perspective, the pandemic has also created opportunities to improve TB care. In this review, we highlight similarities and differences between these two infectious diseases, describe gaps in our knowledge and discuss solutions and priorities for future research.

Halomonas icarae sp. nov., a moderately halophilic bacterium isolated from beach soil in India

A moderately halophilic, Gram-stain-negative, aerobic bacterium, strain D1-1^T, belonging to the genus Halomonas, was isolated from soil sampled at Pentha beach, Odisha, India. Phylogenetic trees reconstructed based on 16S rRNA genes and multilocus sequence analysis of gyrB and rpoD genes revealed that strain D1-1^T belonged to the genus Halomonas and was most closely related to Halomonas alimentaria YKJ-16^T (98.1 %) followed by Halomonas ventosae Al12^T (97.5 %), Halomonas sediminicola CPS11^T (97.5 %), Halomonas fontilapidosi 5CR^T (97.4 %) and Halomonas halodenitrificans DSM 735^T (97.2 %) on the basis of 16S rRNA gene sequence similarity. Sequence identities with other species within the genus were lower than 97.0 %. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of 22.4-30 % and 79.5-85.4 % with close relatives of H. halodenitrificans DSM 735^T, H. alimentaria YKJ-16^T, H. ventosae Al12^T and H. fontilapidosi 5CR^T were lower than the threshold recommended for species delineation (70 % and 95-96 % for dDDH and ANI, respectively). Further, strain D1-1^T formed yellow-coloured colonies; cells were rod-shaped, motile with optimum growth at 30 °C (range, 4-45 °C) and 2-8 % NaCl (w/v; grew up to 24 % NaCl). The major fatty acids were summed feature 8 (C_18 : 1  ω7c/C_18 : 1  ω6c), summed feature 3 (C_16 : 1  ω7c/C_16 : 1  ω6c) and C_16 : 0 and the main respiratory quinone was ubiquinone Q-9 in line with description of the genus. Based on its chemotaxonomic and phylogenetic characteristics and genome uniqueness, strain D1-1^T represents a novel species in the genus Halomonas, for which we propose the name Halomonas icarae sp. nov., within the family Halomonadaceae. The type strain is D1-1^T (=JCM 33602^T=KACC 21317^T=NAIMCC-B-2254^T).

Thermophilic ligno-cellulolytic fungi: The future of efficient and rapid bio-waste management

To accelerate the process of decomposition using consortia of thermophilic ligno-cellulolytic fungi, different crop residues viz. sorghum (SG), soybean (SS), maize (MS), sugarcane (SC), cotton (CS) and pigeon pea (PS) with a varied C:N ratio and sawdust (SD) having high lignin content were collected and used for decomposition process. Compost quality assessed by evaluating different maturity and stability indices at five succeeding stages [first mesophilic (M1), thermophilic (T), second mesophilic (M2), cooling (C) and humification (H)]. A significant reduction was observed in the C:N ratio, biodegradability index, nitrification index, ratio of water-soluble carbon to organic nitrogen (WSC/Org.N) with an increase in concomitant over time while Ash (%), organic matter loss (%), CEC/TOC ratio, cellulose biodegradation ratio (BR) and lignin/cellulose ratio were significantly increased with time. By correlation study, biodegradability index (BI) and fluorescein diacetate (FDA) hydrolysis emerged as the most suitable compost maturity and stability parameters, respectively. Principal component analysis (PCA) results confirmed that BI, BR, WSC/Org. N and FDA can be regarded as key indicators for assessing compost quality. Our findings conclude that fungal consortia of Tricoderma viride, Rhizomucor pusillus, Aspergillus awamori and Aspergillus flavus can accelerate decomposition time from 8 to 12 months (which is normal farming practice) to 120 days.

Role of anti-tubercular treatment for positive endometrial aspirate DNA-PCR reproductive outcome in infertile patients in Indian setting - A randomized trial

AIMS

The aim of the study was to determine the effect of anti-tubercular therapy (ATT) versus no ATT on reproductive outcome in patients with positive endometrial aspirate DNA-PCR for tuberculosis.

SETTINGS AND DESIGN

Department of Obstetrics and Gynecology in collaboration with the Department of Microbiology at the All India Institute of Medical Sciences, New Delhi, India.

METHODS AND MATERIALS

This prospective randomized study was conducted on 100 women in the reproductive age group with primary or secondary infertility, attending the Gynecology OPD at AIIMS. Women with positive endometrial DNA-PCR, patent tubes on laparoscopy, and all other tests being negative for genital TB were randomized into two groups. In Group 1, patients received ATT for 6 months while in Group 2, patients were not given ATT. In patients who did not conceive a repeat endometrial sampling for DNA-PCR was performed at 6 months and 12 months post-laparoscopy.

STATISTICAL ANALYSIS

It was carried out using Stata 11.0 (College Station, TX, USA).

RESULTS

In Group 1 (ATT), 25 women achieved pregnancy with a pregnancy rate of 50% while in Group 2 (no ATT), 21 women achieved pregnancy with a pregnancy rate of 42% and the difference (95% CI) was 8.0% (-11.5%, 27.5%) which was not statistically significant (p=0.422). Difference (95% CI) in the rate of repeat EA DNA-PCR being positive between the two groups at 6 months was 3.1% (-2.9%, 9.1%), p=0.299, while at the end of 12 months, repeat DNA-PCR remained positive in 23 patients in Group 1 and in 26 patients in Group 2. Difference (95% CI) in the rate of repeat EA DNA-PCR being positive between the two groups at 12 months was 2.3% (-13.0%, 17.7%), p=0.767.

CONCLUSION

The present study does not validate ATT for positive DNA-PCR; however, it does provide an evidence to stop over-treating patients on the basis of positive EA DNA-PCR even after they have received a 6 months course of ATT. Repeating PCR at 6 months and at 12 months has no role and ATT should not be repeatedly given to the patient on the basis of repeat DNA-PCR alone.

CLINICAL TRIAL REGISTRATION NUMBER

CTRI/2015/10/006235, www.ctri.nic.in.

Effect of antitubercular treatment on ovarian function in female genital tuberculosis with infertility

AIM:

To evaluate the effect of antitubercular therapy (ATT) on an ovarian function such as ovarian reserve, ovarian dimensions, and ovarian stromal blood flow.

SETTINGS AND DESIGN:

Prospective study design.

MATERIALS AND METHODS:

Fifty infertile women with female genital tuberculosis (FGTB) without tubo-ovarian masses diagnosed by positive acid-fast bacilli culture or epithelioid granuloma on endometrial aspirate or positive polymerase chain reaction with positive findings on laparoscopy or hysteroscopy were recruited. The ovarian function tests were performed on day 2/3 as follicle-stimulating hormone (FSH) levels and anti-Mullerian hormone (AMH) levels. Ovarian dimensions (length, width, and depth) were measured using a transvaginal ultrasound. Mean antral follicle count (AFC) and ovarian stromal blood flow (peak systolic velocity [PSV], pulsatility index (PI), and resistive index [RI]) were measured using a transvaginal ultrasound. All women were started on ATT for 6 months by directly observed treatment strategy. After completion of ATT, all the parameters were repeated.

RESULTS:

There was a significant increase in AMH (2.68 ± 0.97 ng/ml to 2.8 ± 1.03 ng/ml) pre- to post-ATT, nonsignificant increase in FSH (7.16 ± 2.34 mIU/ml to 7.26 ± 2.33 mIU/ml) post-ATT, significant increase in mean AFC (7.40 ± 2.12–8.14 ± 2.17), PSV in the right ovary (6.015–6.11 cm/s) and left ovary (6.05–6.08 cm/s), PI in the right ovary (0.935–0.951 cm/s) and left ovary (0.936–0.957 cm/s), and RI in the right ovary (0.62 ± 0.01–0.79 ± 0.02) and left ovary (0.65 ± 0.02–0.84 ± 0.01) with ATT. There was no significant change in mean ovarian dimensions (ovarian length, breadth, and width) and summed ovarian volume with ATT. On laparoscopy, tubercles were seen in 27 (54%) women. Caseous nodules and encysted ascites were seen in 8% cases each.

CONCLUSION:

ATT improves the ovarian function (AMH and AFC) and ovarian blood flow in women with FGTB.

Association of Mycobacterium tuberculosis in the causation of Eales' disease: an institutional experience

BACKGROUND

Eales' disease is an idiopathic retinal vasculitis characterized by retinal inflammation, ischemia, and neo-vascularisation. It frequently causes massive vitreous haemorrhage and retinal detachment leading to blindness. Although the exact etiology is unknown, this condition is considered to be a consequence of hypersensitivity reaction to tubercular protein due to previous Mycobacterium tuberculosis (M. tuberculosis) infection. This study is aimed at the detection of association of M. tuberculosis in patients with Eales' disease.

MATERIALS AND METHODS

A prospective case-control study was undertaken in 65 clinically diagnosed cases of Eales' disease. Patients with proliferative diabetic retinopathy, neo-vascular proliferation, macular oedema, premacular fibrosis and tractional retinal detachment were taken as controls. M. tuberculosis DNA was detected (MPT64 gene by polymerase chain reaction, PCR) in patients with Eales' disease. Clinical symptoms along with tuberculin skin test (TST) and erythrocyte sedimentation rate (ESR) were used as gold standard for comparing results of PCR.

RESULT

PCR positivity was found in 12 (38.7%) patients with Eales' disease. The PCR positivity was significantly associated with the patients with high TST reading and high ESR values.

CONCLUSION

Patients with a high TST reading and ESR value and a positive PCR in vitreous samples have a high likelihood of having M. tuberculosis as an etiology.

Shape elongation of Zn nanoparticles in silica irradiated with swift heavy ions of different species and energies: scaling law and some insights on the elongation mechanism

Zinc nanoparticles (NPs) embedded in silica were irradiated with swift heavy ions (SHIs) of seven different combinations of species and energies. The shape elongation induced by the irradiations was evaluated by optical linear dichroism (OLD) spectroscopy, which is a sensitive tool for determining the change in the mean aspect ratio (AR) of NPs. Although the mean AR change indicated a linear fluence dependence in the low- and medium-fluence regions, it indicated a nonlinear dependence in the high-fluence region. The data reveal that the elongation efficiency of Zn is correlated with the electronic stopping power 'Se in silica' and is not correlated with either the 'Se in Zn' or the nuclear stopping power. The elongation efficiency plotted as a function of the 'Se in silica' revealed a linear relationship, with a threshold value of ∼2 keV nm(-1), which is the same dependence exhibited by the ion-track formation in silica. The log-log plot showed that the elongation efficiency increased linearly with Se above a critical value of ∼3 keV nm(-1) and steeply decreased with Se to the power of 5 below the critical Se. The steep decrease can be ascribed to the discontinuous nature of the ion tracks, which is expected at Se ∼ 2-4 keV nm(-1) in silica. The fluence Φ dependences of AR - 1 under various irradiations are well-normalized with the electronic energy deposition of SHIs, i.e., the product of Se and Φ, with a Se greater than the same critical value of ∼3 keV nm(-1). The normalized data above the critical value fell on a linear relation, AR(Φ) - 1 ∝ SeΦ, for SeΦ < 2 keV nm(-3) and a sublinear relation, AR(Φ) - 1 ∝ (SeΦ)(1/2) for SeΦ > 2 keV nm(-3). On the basis of these experimental results, we discuss some insights into the elongation mechanism.

Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses

We report the synthesis of Pt nanoparticles and their burrowing into silicon upon irradiation of a Pt-Si thin film with medium-energy neon ions at constant fluence (1.0 × 10(17) ions/cm(2)). Several values of medium-energy neon ions were chosen in order to vary the ratio of the electronic energy loss to the nuclear energy loss (S e/S n) from 1 to 10. The irradiated films were characterized using Rutherford backscattering spectroscopy (RBS), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). A TEM image of a cross section of the film irradiated with S e/S n = 1 shows ≈5 nm Pt NPs were buried up to ≈240 nm into the silicon. No silicide phase was detected in the XRD pattern of the film irradiated at the highest value of S e/S n. The synergistic effect of the energy losses of the ion beam (molten zones are produced by S e, and sputtering and local defects are produced by S n) leading to the synthesis and burrowing of Pt NPs is evidenced. The Pt NP synthesis mechanism and their burrowing into the silicon is discussed in detail.

Rapid identification of clinical mycobacterial isolates by protein profiling using matrix assisted laser desorption ionization-time of flight mass spectrometry

PURPOSE

The purpose of this study was to evaluate the identification of Mycobacterium tuberculosis which is often plagued with ambiguity. It is a time consuming process requiring 4-8 weeks after culture positivity, thereby delaying therapeutic intervention. For a successful treatment and disease management, timely diagnosis is imperative. We evaluated a rapid, proteomic based technique for identification of clinical mycobacterial isolates by protein profiling using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

MATERIALS AND METHODS

Freshly grown mycobacterial isolates were used. Acetonitrile/trifluoroacetic acid extraction procedure was carried out, following which cinnamic acid charged plates were subjected to identification by MALDI-TOF MS.

RESULTS

A comparative analysis of 42 clinical mycobacterial isolates using the MALDI-TOF MS and conventional techniques was carried out. Among these, 97.61% were found to corroborate with the standard methods at genus level and 85.36% were accurate till the species level. One out of 42 was not in accord with the conventional assays because MALDI-TOF MS established it as Mycobacterium tuberculosis (log (score)>2.0) and conventional methods established it to be non-tuberculous Mycobacterium.

CONCLUSIONS

MALDI-TOF MS was found to be an accurate, rapid, cost effective and robust system for identification of mycobacterial species. This innovative approach holds promise for early therapeutic intervention leading to better patient care.

Pneumocystis jirovecii dihydropteroate synthase (DHPS) genotypes in non-HIV-immunocompromised patients: a tertiary care reference health centre study

Studies on Pneumocystis jirovecii dihydropteroate synthase (DHPS) genotypes among non-HIV immunocompromised patients from developing countries are rare. In the present prospective investigation, 24 (11.8%) cases were found to be positive for Pneumocystis jirovecii out of 203 non-HIV patients with a clinical suspicion of Pneumocystis pneumonia (PCP). Dihydropteroate synthase (DHPS) genotype 1 (Thr55+Pro57) was noted in 95.8% P. jirovecii isolates in the present study in contrast to only 4.1% of patients with DHPS genotype 4 (Thr55Ala + Pro57Ser).

Study of dihydropteroate synthase (DHPS) gene mutations among isolates of Pneumocystis jiroveci

BACKGROUND & OBJECTIVES

Pneumocystis jiroveci (also known as P. carinii) causes fatal pneumonia in patients with AIDS and other immunocompromised patients. Co-trimoxazole (trimethoprim + sulphamethoxazole, TMP-SMZ) is the drug of choice for treatment and prophylaxis. Widespread use of sulpha medication has raised the possible selection of resistant P. jiroveci strains worldwide. Non-synonymous polymorphisms associated with sulpha resistance have been observed in P. jiroveci dihydropteroate synthase (DHPS) gene at codons 55 and 57. In view of this, we investigated mutation at DHPS locus amongst P. jiroveci isolates obtained at a tertiary care hospital in north India.

METHODS

Microscopic examination of P. jiroveci in 69 clinical samples obtained from patients suspected to have P. carinii pneumonia (PCP), was performed by Grocott's Gomori methenamine silver and direct fluorescent antibody staining. Molecular studies were carried out by polymerase chain reaction (PCR) using major surface glycoprotein (MSG) as the target gene. Investigations for DHPS mutations were carried at specific 55th and 57th codon using PCR-RFLP (restriction fragment length polymorphism) assay.

RESULTS

Microscopic examination detected P. jiroveci in four cases and MSG gene was amplified in five cases. Further, amplification of DHPS gene was successful in four of the five cases positive by MSG gene PCR. No point mutation was observed and all four isolates presented wild-type sequences at DHPS gene by RFLP analysis.

INTERPRETATION & CONCLUSION

Although our findings suggest that in Indian subpopulation, point mutations in DHPS gene of P. jiroveci are not as common as in other parts of the developed world, further studies are needed.

DOTS at a tertiary care center in northern India: successes, challenges and the next steps in tuberculosis control

BACKGROUND AND OBJECTIVES

The past decade has seen a rapid expansion of directly observed treatment, short-course (DOTS) centers throughout India, under the guidance of the Revised National Tuberculosis Control Programme (RNTCP). While expansion has been rapid and extensive, few reports exist detailing individual DOTS centers' experiences, their challenges, and their successes. We present a brief report on the status of a DOTS center being run at a large tertiary care center in northern India for almost four years (2001-2005).

METHODS

The DOTS center followed RNTCP guidelines for the evaluation and treatment of suspected TB cases. A register carrying detailed information of all patients seen at the DOTS center was kept by the senior clinician. Data from this register were extracted and analyzed for descriptive measures.

RESULTS

A total of 1490 patients were evaluated. Of the 768 patients with cough, 27 per cent (211) were found to be sputum positive for acid-fast bacilli (AFB). Among patients who were initiated on anti-tuberculosis medications, cure was achieved in 92 per cent (71 of 77) of new sputum smear positive patients; treatment completion was achieved in 91 per cent (91 of 100) of extrapulmonary TB (EPTB) and 75 per cent (46 of 61) of sputum-negative pulmonary TB patients. Overall treatment success was achieved in 86 per cent (229 of 266).

INTERPRETATION AND CONCLUSION

Treatment results were in keeping with the RNTCP guidelines. Tertiary care centers appear to be excellent place for education of medical students and operational research. The latter is much needed, as HIV-TB co-infection, multi-drug resistant TB, and EPTB continue to be major public health threats even in the era of DOTS.

Phosphorus leaching at cold temperatures as affected by wastewater application and soil phosphorus levels

Land application of wastewater in the northern-tier United States during winter months has been suggested as a means to reduce cost of building storage lagoons. A study was initiated in 1996 to assess land application of potato-processing wastewater on a 120-ha field at Park Rapids, MN. One objective of this study was to evaluate the effects of soil P levels and temperature on P leaching in soil columns. In this paper, we report the P sorption, desorption, and leaching characteristics of a high-P (>200 mg kg(-1)) and a low-P (<25 mg kg(-1)) surface soil from the wastewater irrigation site. The leaching experiment was done with wastewater at 4 +/- 2 or 10 +/- 2 degrees C. The high-P soil resulted in an equilibrium P concentration of 8.0 mg L(-1) compared with 0.14 mg L(-1) for the low-P soil. When low-P wastewater was applied to the high-P soil, the soil acted as a P source, and the total phosphorus (TP) concentration in the leachate was 3.5 times higher than the input TP concentration (C0). When high-P wastewater was applied to the high-P soil, the soil acted as a P sink retarding the TP concentration in the leachate by 80%. Phosphorus desorption was higher at 10 degrees C compared with 4 degrees C. The results showed that depending on P levels of the soil and the wastewater, reduction or increase in leachate P will occur below the surface soil. However, further mobility of this P under field conditions will depend on the volume and rate of percolating water as well as the sorption-desorption characteristics of the subsoil.

DOTS centre at a tertiary care teaching hospital: lessons learned and future directions

BACKGROUND

In 1993, Government of India started the Revised National Tuberculosis Control Programme (RNTCP). A model Directly Observed Therapy, Short-Course (DOTS) centre was established at the All India Institute of Medical Sciences (AIIMS) to (i) identify the challenges and opportunities in establishing DOTS centres at tertiary care facilities, (ii) to teach the strategies of RNTCP to medical and paramedical staff, and (iii) to undertake relevant operational research connected with tuberculosis (TB) treatment and control. In this communication, we describe the experience of establishing a DOTS centre at India's premier medical institute and discuss the lessons learned.

METHODS

Since September 2001 through November 2002 AIIMS employees and their dependants diagnosed with tuberculosis were enrolled for treatment at AIIMS DOTS centre. One hundred sixty-eight patients were diagnosed as suffering from tuberculosis. Of these 49 patients were referred out and remaining 119 patients were treated at AIIMS DOTS centre.

RESULTS

Treatment success was achieved in 80% (20/25) of new smear positive cases and the DOTS centre achieved other targets set up by the RNTCP. As the results of the pilot study at AIIMS DOTS centre were favourable, the facilities of AIIMS DOTS centre were extended to the general public from September 2002 onwards.

CONCLUSION

Despite tremendous patient load at tertiary care facilities, it is possible to achieve targets established by the RNTCP. However, additional research needs to be conducted especially relating to drug resistance and surrogate markers of failure under RNTCP.

Comparative evaluation of various commercial assays for diagnosis of dengue fever

Dengue fever (DF) is endemic in India and dengue hemorrhagic fever (DHF) has been reported with increasing frequency in the last decade. We evaluated three commercial assays for detection of antibodies to dengue virus, to assess their performance in a diagnostic laboratory. Sera from 58 patients collected during a febrile outbreak in New Delhi in 1997 were studied. The methods evaluated were MRL Diagnostic Dengue Fever Virus IgM Capture ELISA, Pan Bio Dengue Duo IgM and IgG Capture ELISA and Pan Bio Rapid Immunochromatographic test. The MRL ELISA correctly identified 97.8% (43 of 44) of samples as dengue positive while the Pan Bio Duo ELISA and Pan Bio RIT identified 95.45% (42 of 44). The sensitivities of both Pan Bio Duo ELISA and Pan Bio RIT for primary dengue and secondary dengue were 100% and 93.54% respectively. The specificity of three assays were MRL IgM ELISA 100%, Pan Bio Duo ELISA 92.8% and Pan Bio RIT 85.7%.

Use of nucleotide sequencing of the genomic cDNA fragments of the capsid/premembrane junction region for molecular epidemiology of dengue type 2 viruses

The recent emergence of dengue hemorrhagic fever/dengue shock syndrome (DHF/ DSS) in India has been a source of concern. In the present study a quantitative comparison of 406 nucleotide long sequence from the capsid-premembrane junction region (C-PrM) of 9 dengue virus type 2 (DEN-2) isolates from Delhi with 10 DEN-2 isolates from diverse geographic areas provided sufficient information for estimating genetic relationships. The data indicated that the 1996 epidemic of DHF in Delhi was caused by genotype IV strains of DEN-2. This genotype, perhaps, displaced genotype V strains of DEN-2, which was circulating genotype in 1967. The period during which this displacement had occurred is not clear from the present study. Nonetheless, similar experience in four countries in Latin America and in Sri Lanka suggest that the introduction of new genotypes of DEN-2 displacing the circulating genotype may be associated with the appearance of DHF/DSS. More work is required to elucidate this hypothesis. Transitions at nucleotide positions 406 and 431 resulted in amino acid substitutions near (aa position 104, methionine --> valine) and at the hinge region (aa position 112, valine --> alanine) of C-PrM, respectively in all/most genotypes of group III and IV DEN-2 viruses analysed. Most of these virus strains have been isolated from DHF/DSS outbreaks. Significance of this observation is discussed. The data presented in this study suggest the utility of C-PrM sequence analysis for molecular epidemiology of dengue viruses.

Partial nucleotide sequencing and molecular evolution of epidemic causing Dengue 2 strains

To study the genetic variability and to detect evolutionary changes and movement of dengue 2 (DEN-2) strains, nucleotide sequencing of the envelope protein gene and the nonstructural protein 1 gene junction was performed for 9 isolates from the 1996 Delhi epidemic and 1 isolate from the 1967 Delhi epidemic. The epidemic strains had a divergence of 10%-11% from the 1967 strains, but were quite similar to DEN-2 isolates from Seychelles, Somalia, and Torres Strait. In addition, the sequence data were compared to the prototype DEN-2 strain, New Guinea C, and other published DEN-2 sequences from different parts of the world. The phylogenetic analysis by the Molecular Evolutionary Genetics Analysis program suggests that the 1996 Delhi isolates of DEN-2 were genotype IV. The 1967 isolate was similar to a 1957 isolate of DEN-2, P9-122, from India, and was classified as genotype V. This study indicates that earlier DEN-2 strains of genotype V have been replaced by genotype IV.

Possibility of using 131I-albumin as a marker for the estimations of microbial protein synthesis rates in the rumen

Total microbial protein synthesis rates in the rumen of buffaloes were estimated by isotope dilution technique, using 131I-albumin treated with tannic acid as a marker. The animals were fed groundnut cake treated with formaldehyde to meet 50% of their digestible crude protein (DCP) requirement and 2.5% urea molasses mixture was given to meet the remaining requirement of DCP. Wheat straw was fed as the basal roughage. The total average microbial protein synthesis was 58.14 g/day.

The relationship between rumen bacterial growth, intake of dry matter, digestible organic matter and volatile fatty acid production in buffalo (Bos bubalis) calves

1. The production rates of bacteria in the rumen of buffalo (Bos bubalis) calves were estimated using an isotope-dilution technique. A series of fifteen experiments was done with animals given green maize and nine experiments with animals given cowpea (Vigna unguiculata). 2. The turnover time ranged from 205 to 567 min in the group given green maize and from 330 to 648 min in animals offered cowpea. The production rates of bacteria were (mean +/- SE; g/d) 145.77 +/- 7.240 and 237.09 +/- 11.847 in animals given green maize and cowpea respectively. 3. There was a significant correlation between bacterial production rates and dry matter intake, digestible organic matter and total volatile fatty acids formed in the rumen. 4. Regression equations obtained for the two foodstuffs were different suggesting that the bacterial growth rate may vary depending upon the quantity and quality of foodstuff digested and possibly the ratio nitrogen:energy of the foodstuff.

Comparison of the production rates of bacteria in the rumen estimated by using labelled live and formaldehyde treated mixed bacterial cells

The bacteria production rates in the rumen have been estimated by injecting 14C- and 35S-labelled mixed rumen bacteria, either live or killed by treatment with formaldehyde, into the rumen and applying isotope dilution technique. The rate of bacteria production when estimated by using either live- or dead-(protected-)labelled bacterial cells were comparable.

Structural changes in the granulosa lutein cells of pregnant cows between 60 and 245 days

The structural changes in the granulosa lutein cells in the pregnant cows between 60 and 245 days, were observed. The polyhedral or pump cells has an acidophilic cytoplasm around the spherical nucleus. The glycogen granules increased in number up to 230 days of pregnancy. The lipid globules increased in size and amount during advanced pregnancy. The mitochondria showed a wide range of variations in shape and size. The matrix of many mitochondria contained dense inclusions which replaced the entire matrix in late pregnancy. The endoplasmic reticulum was chiefly of smooth type but a few stacks of the rough variety could be seen in the early days of pregnancy. Sometimes, whorls of smooth-surfaced endoplasmic reticulum enclosing mitochondria were seen. The Golgi complex was fully developed in the granulosa cells of all cases studied. The dense granules and lipid globules increased in size and number in the older corpora lutea. The cell surface showed numerous infolding of the plasma membrane.

Measurements in vivo of the rate of production of protozoa in the rumen

The rates of production of protozoa in the rumen of buffalo calves have been estimated using a single-injection isotope dilution technique. The calves were fed at 2 levels of crude protein, namely, 13% lower and 19% higher than that recommended by the National Research Council. The animals were given their rations at 2-h intervals for 3 weeks. Thereafter 14C-labelled rumen protozoa were injected into the rumen of each calf in a single injection. Samples of the rumen liquor were drawn at various time-intervals for 10 h and were analysed for the concentration of protozoa and radioactivity. The decline in the specific radioactivity of protozoa cells in the rumen as a function of time was used for calculating half life (t½). A mathematical equation was used to calculate the rate of production of protozoa. The average t½ was 1077 min for both groups and the rates of production of protozoa were 73·9 and 92·1mg/min in groups fed on low and high planes of crude protein respectively, showing that the production of protozoa is significantly (P < 0·01) higher in animals consuming a ration high in crude protein.