Proteomic Profiling and Pathway Analysis of Acid Stress-Induced Vasorelaxation of Mesenteric Arteries In Vitro

Although metabolic acidosis is associated with numerous pathophysiological conditions and its vasorelaxation effects have been well described in different animal and culture models, the molecular mechanisms of acidosis-induced vasorelaxation are not fully understood. Mesenteric artery models have been used extensively to examine the vascular response to various pathophysiological conditions. Our previous studies and several other reports have suggested the vascular responses of goat mesenteric arteries and human arteries to various stimuli, including acidic stress, are highly similar. In this study, to further identify the signaling molecules responsible for altered vasoreactivity in response to acidic pH, we examined the proteomic profile of acid stress-induced vasorelaxation using a goat mesenteric artery model. The vascular proteomes under acidic pH were compared using 2D-GE with 7 cm IPG strips and mini gels, LC-MS/MS, and MALDI TOF MS. The unique proteins identified by mass spectroscopy were actin, transgelin, WD repeat-containing protein 1, desmin, tropomyosin, ATP synthase β, Hsp27, aldehyde dehydrogenase, pyruvate kinase, and vitamin K epoxide reductase complex subunit 1-like protein. Out of five protein spots identified as actin, three were upregulated > 2-fold. ATP synthase β was also upregulated (2.14-fold) under acid stress. Other actin-associated proteins upregulated were transgelin, desmin, and WD repeat-containing protein 1. Isometric contraction studies revealed that both receptor-mediated (histamine) and non-receptor-mediated (KCl) vasocontraction were attenuated, whereas acetylcholine-induced vasorelaxation was augmented under acidosis. Overall, the altered vasoreactivity under acidosis observed in the functional studies could possibly be attributed to the increase in expression of actin and ATP synthase β.

Proteomic and transcriptomic changes in rat liver following oral feeding of formaldehyde

Formaldehyde (FA), a ubiquitous volatile organic compound present in a wide range of resources, is a hazardous chemical and human carcinogen. Contamination of FA in food, especially perishable commodities like fish and meat, is a major source of exposure, although it is not recommended for use in food and food products owing to its carcinogenicity. Effects of oral feeding of FA have been studied by evaluating general health, haematology and clinical chemistry in rat. Recent studies have shown that FA exposure leads to detrimental cardiovascular effects. It regulates vascular tensions through nitric oxide-cGMP signalling pathway and ion channels in rats. Although FA is an established carcinogen, molecular studies on carcinogenic potential with dose dependency are meagre. In this context, the present study was undertaken to investigate the toxicogenomic and proteomic alterations in liver of rats fed FA through drinking water. By proteomic analysis, 621 proteins/protein-subunits showed differential abundance (proteome data available via ProteomeXchange with identifier PXD010534), whereas 536 differentially-expressed-genes were identified by transcriptome analysis (data available via Sequence Read Archive with identifier SRR7974113). Gene ontology analysis showed that binding, catalysis, signal transduction were affected in formaldehyde-fed rats. Pathway analysis revealed that formaldehyde-exposure activated PI3K-AKT pathway that leads to inhibition of caspase activity thereby assisting cells to survive against apoptosis. Decreased abundance/down-regulation of ANGPT, eNOS, STAT3 proteins/transcripts and increased abundance of EDN1 indicated decrease in angiogenesis and vasodilatation that restricted hepatic cells from becoming tumorigenic; thus, indicating FA could be less toxic and non-tumorigenic at low concentrations.

Applying systems approach for bridging education, research, and patient care in a health sciences university

Systems approach provides a logical and scientific basis for explaining the functioning of a system in a holistic manner. The health sciences university is a system with its three major operations – education, research, and patient care, which can be conceived as inputs, process, and output, respectively. The system is aided by a feedback loop to inform and correct the system. Systems thinking enable us to identify the deficiencies existing in each of the components so that appropriate remedial action can be taken. In this article, we have identified deficiencies in the health sciences system. Further, we have suggested a five-point formula to achieve connection among education, research, and patient care. We need to Form consortia and networks to create a mass movement, Uniform regulations to remove bottlenecks, Reform curricula to make them credit linked and competency based, Inform all through a faculty development initiative, and finally, Transform the system by setting examples and demonstrating success. The initiative taken by the Medical Council of India in introducing a competency-based curriculum for MBBS, and the revised accreditation manual introduced by the National Assessment and Accreditation Council can provide a lot of opportunities to explore the potentiality educational research to answer many questions that can help us in connecting research with education and patient care.

Systems approach in medical education: The thesis, antithesis, and synthesis

Systems approach is a time tested, method of trying to understand the reality holistically, and resolving the issues by problem-solving method. It has resulted in enormous applications in almost every field of knowledge, science, technology, industries, agriculture, and health or education. The main essence of systems thinking lies in minimizing the inputs, optimizing the process to maximize the outputs through continuous feedback, and monitoring. Medical education has been greatly benefitted as the systems approach has influenced all aspects, from delineating the competencies of doctors, designing curriculum that includes comprehensive assessment. However, of late, there has been a debate as to whether the systems approach can really contribute to resolve complex issues such as bringing curricular reforms, or promote policy changes in patient care, education, or research. This involves a paradigm shift from problem-solving approach to “pattern recognition” and adaptive action to correct the system. This review based on critical appreciation, begins with a thesis that systems approach is a great tool. It then exposes its inadequacy to address complex systems. This is antithesis. In the end, a synthesis of both the contradictory views has been proposed as a take home.

Vasorelaxation Caused by Eugenol, Curcumin and Nanocurcumin is Partially Mediated by Activation of Aminoguanidine-sensitive iNOS in the Middle Uterine Artery of Non-pregnant and Pregnant Capra hircus

Natural products like eugenol and curcumin have been reported to control hypertension. The purpose of our study was to examine the role of iNOS in eugenol/curcumin/nanocurcumin–induced vasorelaxation in the middle uterine artery (MUA) obtained from non-pregnant (NP) and pregnant (P) Capra hircus ( Ch). The MUA rings were mounted in an automatic organ bath attached to a powerlab data acquisition system. Vasorelaxation was induced by eugenol/curcumin/nanocurcumin in either the absence or presence of aminoguanidine in phenylephrine precontracted MUA rings. The vasorelaxation response was recorded isometrically by a highly sensitive isometric force transducer automatic organ bath connected to powerlab and analysed using Labchart 7.1.3 software. The maximal vasorelaxation (Rmax) obtained from eugenol, curcumin and nanocurcumin -induced concentration related contractile response elicited in PE- precontracted ED+ MUA rings was 49.5%, 42.6%, and 40.4% in NP, and 79.5%, 55.5%, and 44.1% in P Ch. Aminoguanidine attenuated the Rmax of eugenol, curcumin and nanocurcumin to 28.2%, 28.5%, and 16.4% in MUA of NP, and 57.2%, 57.4%, and 38.0% in MUA of P Ch, respectively. The results demonstrated that vasorelaxation to (i) Eugenol is partly mediated by partial activation of aminoguanidine-sensitive iNOS in the uterine artery and this pathway is augmented in pregnancy, (ii) Nanocurcumin is mediated by activation of aminoguanidine-sensitive iNOS in the uterine artery of NP, but not in P Ch and (iii) Curcumin is mediated by minimal activation of aminoguanidine sensitive iNOS only in the uterine artery of NP, but not in P Ch. In conclusion, eugenol and nanocurcumin possess a greater potential than curcumin in the control of hypertension due to partial activation of iNOS. These nutraceuticals could be useful to improve blood flow to the uterus to maintain oestrus cycle, maternal and fetal health.

Acidosis potentiates endothelium-dependent vasorelaxation and gap junction communication in the superior mesenteric artery

Extracellular pH is an important physiological determinant of vascular tone that is normally maintained within 7.35-7.45. Any change outside this range leads to severe pathological repercussions. We investigated the unknown effects of extracellular acidosis on relaxation in the superior mesenteric artery (SMA) of goat. SMA rings were employed to maintain isometric contractions at extracellular pH (pH_o) 7.4 and 6.8. We analyzed the effect of acidosis (pH_o 6.8) compared to physiological pH (pH_o 7.4) on three signaling mediators of endothelium-dependent hyperpolarization: nitric oxide (NO), prostaglandin I₂ (PGI₂), and myoendothelial gap junctions (MEGJ). NO and cyclic guanosine monophosphate (cGMP) levels were compared between normal and acidic pH. Quantitative real-time PCR (qPCR) studies determined the change in expression of vascular connexin (Cx), Cx37, Cx40, and Cx43. Under acidosis, acetyl choline-induced relaxation was augmented in an endothelium-dependent manner via eNOS-NO-cGMP signaling. Conversely, at normal pH, acetyl choline-induced vasorelaxation was mediated primarily via COX-PGI₂ pathway. The functional activity of MEGJ was increased under acidosis as evident from increased sensitivity of connexin blockers and upregulated gene and protein expression of connexins. In conclusion, acetyl choline-induced augmented vasorelaxation under acidosis is mediated by NOS-NO-cGMP, with a partial role of MEGJ as EDH mediators in the SMA. Present data suggest a novel role of connexin as therapeutic targets to attenuate the detrimental effect of acidosis on vascular tone.

Acidosis reduces the function and expression of α1D-adrenoceptor in superior mesenteric artery of Capra hircus

Objective:

The objective of this study was to characterize the α₁-adrenoceptor (α₁-AR) subtypes and evaluate the effect of acidosis on α₁-AR function and expression in goat superior mesenteric artery (GSMA).

Materials and Methods:

GSMA rings were mounted in a thermostatically controlled (37.0°C ± 0.5°C) organ bath containing 20 ml of modified Krebs-Henseleit solution, maintained at pH_o of 7.4, 6.8, 6.0, 5.5, 5.0, and 4.5. Noradrenaline (NA)- and phenylephrine (PE)-induced contractile response was elicited in the absence or presence of endothelium and prazosin at pH_o of 7.4, 6.0, and 5.0. The responses were recorded isometrically by an automatic organ bath connected to PowerLab and analyzed using Labchart 7.1.3 software. Expression of α_1D-AR was compared at physiological and acidic pH_o using reverse transcription-polymerase chain reaction (RT-PCR).

Results:

NA- and PE-induced contractile responses were attenuated proportionately with a decrease in extracellular pH (pH_o), i.e. 7.4 → 6.8 → 6.0 → 5.5 → 5.0 → 4.5. Endothelium denudation increased the contractile response at both normal and acidic pH_o. Prazosin (1 nM, 10 nM, and 0.1 μM) inhibited the NA- and PE-induced contractile response at pH_o 7.4 and the blocking effect of prazosin was potentiated at pH_o of 6.0 and 5.0. RT-PCR analysis for α_1D-AR in GSMA showed that the mRNA expression of α_1D-AR was decreased under acidic pH_o as compared to physiological pH_o.

Conclusion:

(i) Adrenergic receptor mediates vasoconstriction in GSMA under normal physiological pH_o, and α_1D is the possible subtype involved in this event (ii) acidosis attenuates the vasocontractile response due to reduced function and expression of α_1D-AR and also increased the release of endothelial-relaxing factors.

Molecular characterisation of antimicrobial resistance in Pseudomonas aeruginosa and Acinetobacter baumannii during 2014 and 2015 collected across India

BACKGROUND

Surveillance of antimicrobial resistance (AMR) is of great importance. Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens and emergence of resistance in these have increased the morbidity and mortality rates. This surveillance study was initiated by the Government of India - Indian Council of Medical Research. The aim of this study is to determine the antimicrobial susceptibility profile and to characterise the enzyme mediated antimicrobial resistance such as extended spectrum beta-lactamases (ESBLs) and carbapenemases among multidrug-resistant (MDR) P. aeruginosa and A. baumannii.

MATERIALS AND METHODS

A multi-centric study was conducted from January 2014 to December 2015 with a total number of 240 MDR P. aeruginosa and 312 MDR A. baumannii isolated from blood, cerebrospinal fluid, respiratory, pus, urine and intra-abdominal infections. Kirby-Bauer disc diffusion was done to determine the antimicrobial susceptibility profile. Further, MDR isolates were characterised by multiplex polymerase chain reaction to determine the resistance genes for ESBLs and carbapenemases.

RESULTS

Among the ESBLs, blaVEB (23%), blaTEM (5%) and blaSHV (0.4%) in P. aeruginosa and blaPER (54%), blaTEM (16%) and blaSHV (1%) in A. baumannii were the most prevalent. Likewise, blaVIM (37%), blaNDM (14%), blaGES (8%) and blaIMP (2%) in P. aeruginosa and blaOXA-23like (98%), blaOXA-58like (2%), blaNDM (22%) and blaVIM (3%) in A. baumannii were found to be the most prevalent carbapenemases. blaOXA-51like gene, intrinsic to A. baumannii was present in all the isolates tested.

CONCLUSION

The data shown highlight the wide difference in the molecular mechanisms of AMR profile between P. aeruginosa and A. baumannii. In P. aeruginosa, plasmid-mediated mechanisms are much lesser than the chromosomal mediated mechanisms. In A. baumannii, class D oxacillinases are more common than other mechanisms. Continuous surveillance to monitor the trends in AMR among MDR pathogens is important for implementation of infection control and to guide appropriate empirical antimicrobial therapy.

Co-agglutination test for cysticercus antigen detection in the serum for the diagnosis of cysticercosis

The objective of the study was to develop the co-agglutination (Co-A) test, a rapid slide agglutination test for the diagnosis of cysticercosis. The present study included 21 cases of cysticercosis, which comprised seven cases of clinico-radiologically definite cases of neurocysticercosis (NCC) proven with either computed tomography (CT) scan or magnetic resonance imaging (MRI), eight cases of clinically strong NCC, six cases of extraneural cysticercosis in muscle and eye; 40 non-cysticercal parasitic infection controls; and 20 healthy controls. Hyperimmune cysticercus antiserum was raised in rabbits and was used to coat Staphylococcus aureus (Cowan strain-I) bearing protein A (SAPA) cells, and the Co-A was standardized to detect cysticercal antigen in the serum. Serum samples from 12 out of 21 (57%) cases of cysticercosis were positive for cysticercal antigen by the Co-A test. Of the 12 positive samples, eight were from cases of neurocysticercosis and four from cases of extra-neural cysticercosis. Serum samples from seven out of 40 non-cysticercal parasitic infection controls and serum samples from one out of 20 (5%) healthy controls showed a false-positive reaction for the antigen by the Co-A test. There was a statistically significant difference between the antigen detection rates among cysticercosis patients on one hand, and the patients with other parasitic diseases ( P=0.0014), and healthy controls ( P=0.0003) on the other. The Co-A test appears to be a moderately sensitive and specific test for the diagnosis of cysticercosis.

A case report of an uncommon parasitic infection of human balantidiasis

Balantidium coli, a large, ciliated pathogen, is known to cause balantidiasis in humans. We report a case of B. coli infection in a 37-year-old male with tuberculosis and presenting with fever, anorexia, mild abdominal pain, and episodes of loose stools for 1 week.

Vasorelaxation of goat mesenteric artery is mediated by endothelial Na(+)-K(+)-ATPase

OBJECTIVE

To examine the role of Na(+)-K(+)-ATPase and K(+) channels in mediating vasorelaxation in the superior mesenteric artery of Capra hircus.

MATERIALS AND METHODS

Goat superior mesenteric artery (GSMA) was cut into 1.5-2 mm circular rings and mounted in a thermostatically controlled (37°C ± 0.5°C) organ bath containing 20 ml of modified Krebs-Henseleit saline (MKHS) (pH 7.4), with continuous aeration under 1.5 g tension for 90 min. Endothelium-intact (ED+) or endothelium-denuded (ED-) GSMA ring was contracted with phenylephrine (PE) or 5-hydroxytryptamine (5-HT) (1 μM-0.1 mM) in the absence or presence of ouabain (0.1 μM). KCl (1 μM-10 mM) was added cumulatively to K(+)-free MKHS-pre-contracted (ED+/-) rings in the absence or presence of ouabain (0.1 μM) or barium (1 μM) or 4-aminopyridine (1 μM).

RESULTS

Ouabain did not alter the basal tone of the arterial ring. The contractile response induced by PE (Emax: 50.46 ± 2.68, pD2: 5.53 ± 0.04) and 5-HT (Emax: 30.86 ± 1.33, pD2: 6.17 ± 0.03) in ED+ ring was significantly (P < 0.001) augmented in ED- rings (PE: Emax: 93.30 ± 2.11, pD2: 6.41 ± 0.04; 5-HT: Emax: 95.07 ± 0.99, pD2: 6.27 ± 0.03). The contractile response induced by PE and 5-HT in ED+ or ED- rings in the presence of ouabain was almost identical with that of ED- rings. Vasorelaxation of KCl (Emax: 2.90 ± 1.14, pD2: 3.9 ± 0.03) was significantly attenuated in the presence of ouabain (Emax: 73.8 ± 5.16, pD2: 4.3 ± 0.04), Ba(2+) (Emax: 16.34 ± 4.7, pD2: 3.22 ± 0.02), 4-AP (Emax: 18.16 ± 2.4, pD2: 3.68 ± 0.03), ouabain and Ba(2+) (Emax: 70.09 ± 3.66, pD2: 4.41 ± 0.04), and ouabain and 4-AP (Emax: 66.98 ± 4.61, pD2: 4.13 ± 0.06).

CONCLUSION

The vasorelaxation in GSMA is mediated by the endothelium-derived hyperpolarizing factor (EDHFs) such as ouabain-sensitive Na(+)-K(+)-ATPase, KIR and Kv channels.

Unusual manifestation of Salmonella enterica serotype enteritidis infection in a case of Langerhans cell histiocytosis

Nontyphoidal Salmonella (NTS) are established foodborne pathogens, most commonly reported in cases of gastroenteritis. These pathogens are however, increasingly being implicated in cases of bacteraemia and other extraintestinal manifestations. We report a case of a scalp abscess due to Salmonella enterica serotype Enteritidis, which is a serotype of NTS, in a child suffering from a haematologic malignancy. The child was on steroid and anticancer chemotherapy and developed the abscess secondary to bacteraemia with Salmonella Enteritidis. The abscess was drained and resolved following a course of intravenous antibiotic treatment.

Co-infection with Nocardia asteroides complex and Strongyloides stercoralis in a patient with autoimmune hemolytic anemia

We describe an unusual case of pulmonary nocardiosis co-existing with Strongyloides stercoralis hyperinfection syndrome in a patient with autoimmune hemolytic anemia who was being treated with corticosteroids. This case highlights the importance of being aware of the possibility that infections can co-exist in immunosuppressed patients. To the best of our knowledge, this is the first report of co-infection with Nocardia asteroides and S. stercoralis.

Fatal meningitis caused by vancomycin-resistant enterococci: report of two cases from south India

Vancomycin-resistant enterococci rarely cause meningitis and present a therapeutic challenge. Antimicrobial susceptibility testing was done for strains of Enterococcus species isolated from CSF samples of patients with meningitis by phenotypic methods. Multiplex polymerase chain reaction was performed to determine the genetic basis of vancomycin resistance of such isolates. We report here two cases of enterococcal meningitis caused by vancomycin-resistant Enterococcus species. One of the isolates was identified as Enterococcus faecalis and the other as Enterococcus gallinarum. We also report the simultaneous presence of vanC1 and vanA resistance genes in the strain of E. gallinarum. To the best of our knowledge, this is the first report of vanA resistance gene in an isolate of E. gallinarum from the Indian subcontinent. This is also the first Indian report of vancomycin-resistant Enterococcus causing meningitis.

Molecular description of plasmid-mediated AmpC β-lactamases among nosocomial isolates of Escherichia coli & Klebsiella pneumoniae from six different hospitals in India

BACKGROUND & OBJECTIVES

Plasmid mediated AmpC β-lactamase (PMABL) resistance in Escherichia coli and Klebsiella spp. is an emerging problem worldwide. Phenotypic methods are commonly used for detection of PMABL production in Gram-negative isolates, but molecular data about the prevalence of plasmid-mediated AmpC-type resistance at the national level are needed. Hence, a prospective study was undertaken to determine the occurrence of PMABL gene and its types among clinical isolates of E. coli and K. pneumoniae obtained from six different hospitals in India.

METHODS

A total of 241 nosocomial isolates of K. pneumoniae (n=109) and E.coli (n=132) from six geographically distant hospitals in India were included. These were screened for cefoxitin resistance. AmpC disk test and modified three dimensional extraction test were used for phenotypic detection of PMABL production. Molecular types were determined by a multiplex PCR.

RESULTS

Among the 241 isolates, 187 (77.5%) were found to be cefoxitin resistant (K. pneumoniae n=83, E. coli n=104). AmpC activity was detectable in 153 (63.4%) isolates, (K. pneumoniae n=69, E. coli n=84). By PCR, the plasmid encoded AmpC genes were found in 92 (38.1%) isolates and the molecular types of the genes detected predominantly were DHA, CIT followed by MOX and ACC types.

INTERPRETATION & CONCLUSIONS

A high percentage of plasmid-encoded AmpC enzymes was noted in E. coli and K. pneumonia isolates obtained from different parts of the country. Phenotypic methods alone may not reflect the true number of PMABL producers. Genotypic methods need to be employed in national surveillance studies.

Drug resistance in malaria

Antimalarial chemotherapy is an important component of all malaria control programmes throughout the world. This is especially so in light of the fact that there are no antimalarial vaccines which are available for clinical use at present. Emergence and spread of malaria parasites which are resistant to many of the available antimalarials today is, therefore, a major cause for concern. Till date, resistance to all groups of antimalarials excluding artemisinin has been reported. In recent years, in vitro resistance to even artemisinin has been described. While resistance to antibacterial agents has come to prominence as a clinical problem in recent years, antiparasitic resistance in general and antimalarial resistance in particular has not received much attention, especially in the Indian scenario. The present review deals with commonly used antimalarial drugs and the mechanisms of resistance to them. Various methods of detecting antimalarial resistance and avoiding the same have also been dealt with. Newer parasite targets which can be used in developing newer antimalarial agents and antimalarials obtained from plants have also been mentioned.

Seroprevalence of lymphatic filariasis at Puducherry

Lymphatic filariasis is a major vector borne disease prevalent in the tropics. This study was carried out to estimate the seroprevalence of lymphatic filariasis in and around Puducherry using indirect haemaggulutination test. Of the 5056 clinically suspected cases, 2214 (43.78%) were found to be positive, of whom majority were males (57.8%) belonging to the age group of 21-40 years, indicating that lymphatic filariasis mainly affects the adolescents and adults mainly. This high seroprevalence is a matter of immediate concern and necessary control programme is urgently required to check the transmission of filariasis.

Study of CTX-M Type of Extended Spectrum β-Lactamase among Nosocomial Isolates of Escherichia coli and Klebsiella pneumoniae in South India

Data on CTX-M type extended-spectrum β-lactamase (ESBL) produced by Gram-negative bacteria by molecular methods are limited from India. This study was conducted to investigate the prevalence of CTX-M type ESBL producing Escherichia coli and Klebsiella pneumoniae from nosocomial isolates in a tertiary care hospital in southern India. A total of 179 clinical isolates of K. pneumoniae (n = 72) and E. coli (n = 107) were obtained in a period of 3 months and assessed for ESBL production phenotypically. Associated resistance to a panel of antibiotics and Minimum Inhibitory Concentration for 3rd generation cephalosporins was determined. Phenotypically ESBL positive isolates were subjected to PCR for blaCTX-M gene using two sets of primers for the simultaneous detection of all the five major groups of CTX-M types. All the positive isolates were then subjected to a group specific PCR to detect the prevalent group. Out of 179 isolates, 156 (87.1%) were positive for ESBL phenotypically, which includes 39.2% of K. pneumoniae and 60.8% of E. coli. All of them were examined by PCR using two primers for the presence of blaCTX-M genes. Among the 156 phenotypic positive isolates, 124 (79.4%) were positive for blaCTX-M genes, of which 45 (36.2%) were K. pneumoniae, 79 (63.7%) were E. coli. When the 124 positive clinical isolates were further tested with CTX-M group-specific primers, all were positive for the CTX-M-1 group. Our findings document evidence of the high prevalence of multidrug resistant CTX-M group 1 type ESBL among nosocomial isolates in this region. High co-resistance to other non-β-lactam antibiotics is a major challenge for management of ESBL infections. This is alarming and calls for the judicious use of carbapenems, especially in developing countries. This has significant implications for patient management, and indicates the need for increased surveillance and for further molecular characterization of these isolates.

Ampc Beta lactamases among gram negative clinical isolates from a tertiary hospital, South India

AmpC β-lactamases are cephalosporinases that hydrolyze cephamycins as well as other extended-spectrum cephalosporins and are poorly inhibited by clavulanic acid. Although reported with increasing frequency, the true rate of occurrence of AmpC β-lactamases in different organisms, including members of Enterobacteriaceae, remains unknown. The present study was designed to determine the occurrence of AmpC enzyme-harbouring Gram-negative clinical isolates in a tertiary care hospital in Pondicherry state, South India. A total of 235 Gram negative clinical isolates were tested for resistance to cefoxitin, third generation cephalosporin (3GC) antibiotics, ampicillin, amikacin, co-trimoxazole, gentamicin, meropenem and tetracycline by disc diffusion method. Isolates found resistant to 3GC and cefoxitin were tested for the production of AmpC β -lactamases by three dimensional extraction method and AmpC disc method. Isolates found to sensitive to 3GC were subjected to disc antagonism test for inducible AmpC production. One hundred and thirty four (57%) strains were resistant to 3GC, among which 63(47%) were positive for plasmid-mediated AmpC beta lactamases production. Among the 101 strains sensitive to 3GC, 23 (22.7%) revealed the presence of inducible AmpC beta lactamases by disc approximation test. A total of 80.9% (51/63) of screen positive isolates were detected by Amp C disc test and 93.6% (59/63) by three dimensional extraction method. Out of the 86 AmpC producers, 67 (77.9%) were cefoxitin resistant .Inducible AmpC was not found in Esch.coli and Klebsiella spp. The AmpC producers also concurrently showed multidrug resistance pattern. AmpC producers were found to be prevalent in our hospital and though three dimensional extraction test detects AmpC better, the disk test is easier to perform routinely and is user- friendly.

Persistent diarrhea: risk factors and outcome

OBJECTIVE

To identify risk factors associated with Persistent diarrhea (PD) and deaths due to PD.

METHODS

This prospective case control study included 60 children with PD (cases) and 60 children (controls) with acute diarrhoea (AD). Detailed history, examination and appropriate investigations were done for all children. Crude Odds ratio was calculated for each risk factor by univariate analysis and adjusted odds ratio was calculated by multivariate logistic regression.

RESULTS

Prior antibiotic use, steroid use, anemia, vitamin A deficiency, malnutrition, LRI, UTI, oral candidiasis, and hyponatremia, were statistically significant risk factors by univariate analysis. Prior antibiotic use, vitamin A deficiency, malnutrition and LRI were independently associated with PD by multivariate logistic regression analysis. The risk factors for mortality were stool frequency more than 10 times per day, severe malnutrition, oral candidiasis, hypoalbuminemia and HIV positivity.

CONCLUSIONS

The presence of these risk factors should alert the clinician to take appropriate measures, to decrease the mortality.

Role of Na-K ATPase enzyme in vascular response of goat ruminal artery

Objective:

To study the role of Na⁺, K⁺- ATPase enzyme in the vascular response of goat ruminal artery.

Materials and Methods:

Ruminal artery was obtained in chilled aerated modified Krebs-Henseleit solution (KHS) from a local slaughterhouse and transported in ice for further processing. The endothelium intact arterial ring was mounted in a thermostatically controlled (37 ± 0.5°C) organ bath containing 20 ml of modified KHS (pH 7.4) bubbled with oxygen (95%) and CO₂ (5%) under 2g tension. An equilibration of 90 min was allowed before addition of drugs into the bath. The responses were recorded isometrically in an automatic organ bath connected to PowerLab data acquisition system. In order to examine intact functional endothelium, ACh (10 μM) was added on the 5-HT (1.0 μM) - induced sustained contractile response. Similarly, functional characterization of Na⁺, K⁺-ATPase activity was done by K⁺-induced relaxation (10 μM-10 mM) in the absence and presence of ouabain (0.1 μM/ 0.1 mM), digoxin (0.1 μM) and barium (30 μM).

Results:

ACh (10⁻⁵ M) did not produce any relaxing effect on 5-HT-induced sustained contractile response suggesting that vascular endothelium has no significant influence on the activation of sodium pump by extracellular K⁺ in ruminal artery. Low concentration of Ba²⁺ (30 μM) (IC₅₀: 0.479 mM) inhibited K⁺-induced relaxation suggesting K_ir (inward rectifier) channel in part had role in K⁺-induced vasodilatation in ruminal artery. Vasorelaxant effect of KCl (10 μM-10 mM) in K⁺-free medium is also blocked by ouabain (0.1 μM and 0.1 mM) (IC₅₀:0.398 mM and IC₃₅: 1.36 mM), but not by digoxin (0.1 μM) (IC₅₀ 0.234 mM) suggesting that ouabain sensitive Na⁺, K⁺-ATPase isoform is present in the ruminal artery.

Conclusion:

In the goat ruminal artery functional regulation of sodium pump is partly mediated by K⁺ channel and ouabain sensitive Na⁺, K⁺ ATPase.

Neonatal melioidosis: a case report from India

Melioidosis, caused by Burkholderia pseudomallei , is an infectious disease of major public health importance in Southeast Asia and Australia. We report, for the first time from the Indian subcontinent, a case of melioidosis in a neonate, its clinical presentation, microbiological diagnosis, possible mode of transmission and outcome. A pre-term female baby developed respiratory distress soon after birth. The child was febrile, had tachypnea, grunting, normal heart rate with a low pulse volume and poor peripheral perfusion. Chest X-ray revealed right-sided bronchopneumonia. B. pseudomallei was isolated from the blood culture of the neonate collected aseptically. The neonate was successfully treated with meropenem.

Simple screening tests for detection of carbapenemases in clinical isolates of nonfermentative Gram-negative bacteria

BACKGROUND & OBJECTIVE

The production of carbapenemases is an important mechanism responsible for the carbapenem resistance. A simple and inexpensive testing method for screening of carbapenemase producers is essential. A prospective study was undertaken to detect metallo-beta-lactamases (MBLs) and AmpC beta-lactamases in nonfermentative Gram negative bacteria and to evaluate the various methods for detection of carbapenemases and MBLs.

METHODS

A total of 100 Acinetobacter spp. (78 A. baumannii and 22 A. lwoffii) and 140 Pseudomonas spp. (103 P. aeruginosa and 37 other Pseudomonas spp.) were screened for meropenem resistance by Kirby-Bauer disc diffusion method. Modified Hodge test, EDTA disk synergy (EDS) test and AmpC disk test were used for the detection of carbapenemases, MBLs and AmpC beta-lactamases, respectively.

RESULTS

Forty six (59.0%) A. baumannii, 7 (31.8%) A. lwoffii, 32 (31.1%) P. aeruginosa and 7 (18.9%) Pseudomonas spp. were resistant to meropenem. Among the 32 meropenem resistant P. aeruginosa, 15 (46.9%) were AmpC beta-lactamase producers, 16 (50.0%) MBL producers by EDS test, but only 9 (28.1%) found positive for carbapenemases by modified Hodge test. Among the 46 meropenem resistant A. baumannii, 31 (67.4%) were AmpC beta-lactamase producers, 3 (6.5%) MBL producers, but only 1 (14.3%) was positive for carbapenemases by modified Hodge test. One P. aeruginosa was positive for carbapenemase by modified Hodge test, but was negative for MBL and AmpC beta-lactamase.

INTERPRETATION & CONCLUSION

MBL production is an important mechanism of carbapenem resistance among Pseudomonas species but not among Acinetobacter species. EDS is more sensitive for detection of MBLs than modifi ed Hodge test. Both EDTA-meropenem and EDTA-ceftazidime combination must be used to detect all the MBL producers. Carbapenemases other than MBL may also be responsible for carbapenem resistance. AmpC beta-lactamase is also a contributory factor for carbapenem resistance among the isolates in the hospital.

A comparative study of blood smear, QBC and antigen detection for diagnosis of malaria

Rapid diagnosis is prerequisite for effective treatment and reducing mortality and morbidity of malaria. This study was taken up to compare the efficacy of various methods available, i.e., thick and thin smear, quantitative buffy coat (QBC), plasmodium lactate dehydrogenase and aldolase in blood of patient. A total of 411 samples were collected from patients presenting with classic symptoms of malaria. For traditional microscopy; thick and thin smears were prepared and stained with Leishman's stain, taking thick smear as gold standard, thin smear had a sensitivity and specificity of 54.8% and 100%, respectively. QBC and antigen detection was done using commercially available kits; out of 411 samples, QBC and Malariagen were positive in 66 and 62 cases, with a sensitivity of 78% and 75%, respectively. Leishman's thick smear, although cost effective, is difficult to interpret for inexperienced microscopists; so if facilities are available, QBC should be used for routine diagnosis. In places where facilities are not available, rapid, simple and easy to interpret antigen detection test can be used despite low sensitivity.

Nosocomial cutaneous zygomycosis in a patient with diabetic ketoacidosis

Zygomycosis is an opportunistic fungal infection with a fulminant course. Varying clinical forms have been described, including cutaneous zygomycosis, which is mainly observed in diabetic and burns patients. We report herein a case of cutaneous zygomycosis of the nose in a 26-year-old female patient with diabetic ketoacidosis, developing secondary to the application of non-elasticized adhesive tape probably contaminated with fungal spores.

Screening for methicillin-resistant Staphylococcus aureus carriers among patients and health care workers of a tertiary care hospital in south India

A total of 200 subjects were screened for carriage of methicillin-resistant Staphylococcus aureus (MRSA) at different sites using oxacillin blood agar and mannitol salt agar with oxacillin. Overall carriage rate was 8.5%, with the highest rate in inpatients (15.6%) while the lowest was seen in health care workers (1.8%). The commonest site of colonization was the anterior nares. Oxacillin blood agar was found to be superior to mannitol salt agar with oxacillin for the isolation of MRSA. Male sex and prolonged hospital stay were found to be the major risk factors for MRSA colonization.

Effect of KATP channel openers on myogenic and neurogenic responses in goat urinary bladder

Isolated goat detrusor muscle exhibited spontaneous contractility with an irregular amplitude and frequency. The spontaneity of detrusor muscle exhibited a mean amplitude as 11.99 +/- 0.83 mm and frequency as 1.37 +/- 0.16/min. KATP-channel openers namely, cromakalim or pinacidil (10(-7) - 10(-4) M) added cumulatively, elicited a concentration-related inhibition of both amplitude and rate of spontaneous contractions. The mean IC50 values for both amplitude and frequency for cromakalim were 3.3 x 10(-6) M and 2.9 x 10(-6) M, respectively; and for pinacidil were 2.0 x 10(-5) M and 1.5 x 10(-5) M, respectively. Glibenclamide, a KATP-channel blocker inhibited the cromakalim-induced concentration-related relaxation of spontaneous contractions with a significant increase in its mean IC50. ACh-induced concentration-related contractile response was inhibited in the presence of either cromakalim (10(-4) M) or pinacidil (10(-4) M). The mean EC50 value of ACh, in the presence of cromakalim (2.5 x 10(-3) M) was significantly increased as compared to the control (1.2 x 10(-6) M). In the presence of glibenclamide (10(-5) M) the inhibitory effect of cromakalim was significantly reduced with consequent decrease in the EC50 value (1.9 x 10(-5) M). Application of EFS (30 V and 5 ms) on goat urinary bladder strips at 1, 2, 5, 10, 20 and 30 Hz elicited frequency-related contractile responses. Both cromakalim and pinacidil caused a rightward shift in the frequency-related contractile response curve with significant increase in the mean EF25 and EF50 values, respectively. In the presence of glibenclamide (10(-4) M), the frequency-related inhibitory response curve was shifted to left with significant (P < 0.001) increase in the mean EF25, EF50 and EF75. The present results suggest that in the goat detrusor muscle, agonist and EFS-induced contractile responses were more potently inhibited by cromakalim than pinacidil with activation of glibenclamide sensitive KATP channels.

Cryptococcal meningoencephalitis diagnosed by blood culture

Increase in cryptococcal infection has been noticed after acquired immunodeficiency syndrome pandemic. Cryptococcus neoformans can be isolated from blood in the process of dissemination to brain. We report a case of cryptococcal fungaemia in a patient whose cerebrospinal fluid was negative for Cryptococcus neoformans. Retrospective analysis revealed human immunodeficiency virus seropositivity of the patient. He was treated with amphotericin B and fluconazole. Antiretroviral therapy was started, however, the patient succumbed to the infection.

Reverse passive haemagglutination (RPHA) test for detection of mycobacterial antigen in the cerebrospinal fluid for diagnosis of tubercular meningitis

BACKGROUND

Various serological techniques have been developed to detect antibodies and antigens in the cerebrospinal fluid (CSF) for diagnosis of tubercular meningitis. Most of the serological assays are ELISA based. Attempts have been made to use much simpler antigen detection techniques like the reverse passive haemagglutination (RPHA)which is simple and cost-effective.

AIMS

To evaluate the reverse passive haemagglutination (RPHA) test for detection of mycobacterial antigens in the CSF for diagnosis of tubercular meningitis.

METHODS

In the present study, we have made the use of polyclonal antiserum against heat killed whole Mycobacterium tuberculosis bacilli to sensitize the RBCs in RPHA to detect antigens in clinically suspected cases. A total of 46 cases (clinically suspected TBM 24, culture proven TBM 2, non- TBM cases 20) were included in the present study for detecting M. tuberculosis antigen in the CSF specimens.

RESULTS

Of the 26 test CSF specimens, 13 CSF specimens were positive by RPHA while 4 of the 20 control CSF specimens were also reactive. Two culture positive specimens included in the study were positive by RPHA. Of the 4 control CSF specimens positive by RPHA, 3 were culture proven cases of pneumococcal meningitis and 1 was a case of cryptococcal meningitis. The RPHA is found to be 50% sensitive and 80% specific; and showed a 76.4 % positive predictive value and a 55.2 % negative predictive value.

CONCLUSION

The RPHA is a simple test that could be used as an adjunct in diagnosing TBM. It does not require any special equipment or technically trained or skilled manpower. It is economical and can be afforded for use in community where TBM is more prevalent. Even though the present study showed a poor sensitivity and specificity, further identification, characterization and evaluation of better immuno-dominant and specific antigens or epitopes, and the usage of antibodies developed against such mycobacterial antigens might improve the sensitivity and specificity of this test.

Antifungal susceptibility of Cryptococcus neoformans to amphotericin B and fluconazole

Cryptococcus neoformans has emerged as an important opportunistic fungal pathogen in immunocompromised individuals. The therapeutic options of C. neoformans an opportunistic fungal pathogen include flucytosine, amphotericin B, and azole agents. However in the present scenario, emergence of resistance has been reported, hence this study was undertaken to evaluate antifungal susceptibility pattern of C. neoformans isolates from this southern part of India. Ten isolates of C. neoformans were tested against Amp B and fluconazole, of which 7 were susceptible to both and a single isolate of C. neoformans var gatti was resistant to both with MIC of 32mg/ml and 64mg/ml respectively.

Hypothyroid state reduces calcium channel function in 18-day pregnant rat uterus

Hypothyroidism significantly reduced the mean amplitude and increased the mean frequency of spontaneous rhythmic contractions in 18 day pregnant rat uterus. Nifedipine (10(-12)-10(-9) M) and diltiazem (10(-10)-10(-6) M) caused concentration related inhibition of the myogenic responses of the uterine strips obtained from both pregnant and hypothyroid state. However, nifedipine was less potent (IC50:2.11 x 10(-11) M) in pregnant hypothyroid state as compared to pregnant control (IC50: 3.1 x 10(-12) M). Similarly, diltiazem was less potent (IC50: 3.72 x 10(-9) M) in inhibiting the uterine spontaneous contractions in hypothyroid than in pregnant rat uterus (IC50:5.37 x 10(-10) M). A similar decrease in the sensitivity to nifedipine and diltiazem for reversal of K+ (100 mM)-induced tonic contraction and K(+)-stimulated 45Ca2+ influx was observed with these calcium channel antagonists in uterus obtained from hypothyroid pregnant rats compared to the controls. Nifedipine-sensitive influx of 45Ca(2+)-stimulated either by K+ (100 mM) or by Bay K8644 (1,4-dihydro-2,6-methyl-5-nitro-4-[2'-(trifluromethyl)phenyl]-3-pyridine carboxylic acid methyl ester) (10(-9) M) was significantly less in uterine strips from hypothyroid rats compared to controls. The results suggest that the inhibition of uterine rhythmic contractions may be attributable to a reduction in rat myometrial Ca2+ channel function in the hypothyroid state.

Guinea worm infection of urinary bladder manifesting as obstructive uropathy in rural Maharashtra

Guinea worm or Dracunculus medinensis is a well-documented helminthic infestation in many areas of Asia. In this report, we describe a rare case of guinea worm infestation in a 25-year-old woman who had developed symptoms of obstructive uropathy, in whom fragments of guinea worm were removed after urethral catheterization. To the best of our knowledge, adult guinea worm occurring in the urinary bladder has not been previously described.

Cysticercosis of the eye in South India--a case series

PURPOSE

To study the clinical presentation and treatment outcome of patients with ocular cysticercosis in southern India.

METHODS

This study included 10 patients who were diagnosed to have ocular or adnexal cysticercosis over a period of one year in Pondicherry, India. The clinical presentation, results of investigation and treatment outcome of the cases were analysed retrospectively.

RESULTS

Age of these patients ranged from 12 to 55 years. Four presented with loss of vision, two with a swelling in the eyelid, one with proptosis, one with diplopia and two with conjunctival involvement. ELISA for cysticercus antibodies in serum was positive in all cases. Albendazole and prednisolone were given for the treatment of these cases. Two patients responded well to treatment and were completely cured of the disease. There was partial improvement in 6 cases. Surgery in the form of excision was performed in two cases following a course of medical therapy. There was no significant change in visual acuity in eyes with intraocular cysticercosis following treatment.

CONCLUSION

Ultrasonography B scan and ELISA for anticysticercal antibodies help to establish the diagnosis of ocular cysticercosis. A combination of oral albendazole and corticosteroids is found to be effective in confirmed cases. Intraocular cysticercosis is associated with a poor prognosis for vision.