Host-induced silencing of Mi-msp-1 confers resistance to root-knot nematode Meloidogyne incognita in eggplant.

RNA interference (RNAi)-based host-induced gene silencing (HIGS) is emerging as a novel, efficient and target-specific tool to combat phytonematode infection in crop plants. Mi-msp-1, an effector gene expressed in the subventral pharyngeal gland cells of Meloidogyne incognita plays an important role in the parasitic process. Mi-msp-1 effector is conserved in few of the species of root-knot nematodes (RKNs) and does not share considerable homology with the other phytonematodes, thereby making it a suitable target for HIGS with minimal off-target effects. Six putative eggplant transformants harbouring a single copy RNAi transgene of Mi-msp-1 was generated. Stable expression of the transgene was detected in T1, T2 and T3 transgenic lines for which a detrimental effect on RKN penetration, development and reproduction was documented upon challenge infection with nematode juveniles. The post-parasitic nematode stages extracted from the transgenic plants showed long-term RNAi effect in terms of targeted downregulation of Mi-msp-1. These findings suggest that HIGS of Mi-msp-1 enhances nematode resistance in eggplant and protect the plant against RKN parasitism at very early stage.

Dissemination of methicillin-resistant Staphylococcus aureus SCCmec type IV and SCCmec type V epidemic clones in a tertiary hospital: challenge to infection control.

Two-hundred MRSA strains from inpatients with healthcare-associated (HA) and 100 MRSA strains from outpatients with community-associated (CA) skin and soft tissue infections (SSTIs) were tested for antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec) typing, Panton-Valentine leucocidin (PVL) toxin, seh and arcA genes. Based on SCCmec typing, HA-MRSA isolates were further divided into HA-SCCmec I/II/III MRSA and HA-SCCmec IV/V MRSA, and CA-MRSA isolates into CA-SCCmec I/II/III MRSA and CA-SCCmec IV/V MRSA. SCCmec types were further characterized by pulsed-field gel electrophoresis, spa typing and multi-locus sequence typing. Seventy-five (37·5%) HA-MRSA isolates and 83/100 CA-MRSA isolates were SCCmec IV/V genotype. HA-SCCmec IV/V MRSA was associated with malignancy (P = 0·03) and bone fractures (P = 0·02) compared to CA-SCCmec IV/V MRSA. HA-SCCmec IV/V MRSA was associated with PVL gene carriage compared to HA-SCCmec I/II/III MRSA (P < 0·001). ST22-MRSA-IV (EMRSA-15), ST772-MRSA-V, and ST36-MRSA-IV and ST239:EMRSA-I:III were the major clones identified. Our study documents the emergence of SCCmec IV and SCCmec V MRSA clones in an Indian hospital.

Antigen sequence typing of outer membrane protein (fetA) gene of Neisseria meningitidis serogroup A from Delhi & adjoining areas.

BACKGROUND & OBJECTIVES: Meningitis caused by Neisseria meningitidis is a fatal disease. Meningococcal meningitis is an endemic disease in Delhi and irregular pattern of outbreaks has been reported in India. All these outbreaks were associated with serogroup A. Detailed molecular characterization of N. meningitidis is required for the management of this fatal disease. In this study, we characterized antigenic diversity of surface exposed outer membrane protein (OMP) FetA antigen of N. meningitidis serogroup A isolates obtained from cases of invasive meningococcal meningitis in Delhi, India. METHODS: Eight isolates of N. meningitidis were collected from cerebrospinal fluid during October 2008 to May 2011 from occasional cases of meningococcal meningitis. Seven isolates were from outbreaks of meningococcal meningitis in 2005-2006 in Delhi and its adjoining areas. These were subjected to molecular typing of fetA gene, an outer membrane protein gene. RESULTS: All 15 N. meningitides isolates studied were serogroup A. This surface exposed porin is putatively under immune pressure. Hence as a part of molecular characterization, genotyping was carried out to find out the diversity in outer membrane protein (FetA) gene among the circulating isolates of N. meningitidis. All 15 isolates proved to be of the same existing allele type of FetA variable region (VR) when matched with global database. The allele found was F3-1 for all the isolates. INTERPRETATION & CONCLUSIONS: There was no diversity reported in the outer membrane protein FetA in the present study and hence this protein appeared to be a stable molecule. More studies on molecular characterization of FetA antigen are required from different serogroups circulating in different parts of the world.

Deciphering Intermediate Nugent scores: Utility of Real-time PCR for Bacterial Vaginosis diagnosis.

PURPOSE: To optimize real-time PCR assays for diagnosis of Bacterial Vaginosis (BV) and determine cut-off loads by ROC analysis for Gardnerella vaginalis, Atopobium vaginae and Lactobacillus spp. as compared to Nugent scoring (Gold standard) in clinical samples. RESULTS: Out of 125 women, 34 were positive, 26 intermediate and 65 negative for BV by Nugent scoring. All three real-time PCR assays were found to be highly sensitive & specific and AUC suggested excellent diagnostic accuracy. An optimal cut-off was >9.45 × 103 copies/ ml, >3.34 × 103 copies/ ml & ≤ 18.63 × 103 copies/ ml for G. vaginalis, A. vaginae and Lactobacillus spp. respectively, in BV positives. Gram staining and qPCR were discordant only in patients with intermediate scores (n = 26) where qPCR identified 15 (57.69%) as positive and 11 (42.3%) as negative. CONCLUSION: PCR-based molecular BV diagnosis is more accurate and can be used for deciphering intermediate Nugent scores.

Effect of Pain Neuroscience Education with Conventional Physiotherapy via Telerehabilitation on Pain Catastrophizing and Function in Patients with Osteoarthritis Knee: A Randomized Controlled Trial.

Aim: By explaining to the patient the biological processes underneath their pain condition, pain neuroscience education (PNE) is a form of educational intervention that aims to relieve pain and impairment. Materials and Methods: Patients with knee osteoarthritis (OA) referred to outpatient physiotherapy clinic in India during August 2021 to June 2022 were asked to participate. Out of the eligible patients, 35 were randomly assigned to PNE group and 35 to the control group. Self-reports of Pain Catastrophizing Scale (PCS), Patient Specific Function Scale (PSFS), and Numerical Pain Rating Scale (NPRS) were recorded at baseline (T1) and at 2 weeks (T2). Results: After 2 weeks of follow-up, all the three outcome measures were found to be significant in the PNE group. The results of the unpaired t-test revealed statistically significant result posttest for PCS (mean difference 11.4) and NPRS (mean difference 1.20). There was no mean difference found in the patient function (PSFS) between groups. Conclusion: The results suggest that adding a program of PNE to conventional physiotherapy exercises led to a greater reduction in pain catastrophization, patient-specific function, and pain intensity rather than conventional physiotherapy alone in patients with knee OA at 2 weeks' follow-up.

Evaluation of an opa gene-based nucleic acid amplification test for detection of Neisseria gonorrhoeae in urogenital samples in North India.

Due to the poor positive predictive value of nucleic acid amplification tests (NAATs) for gonorrhoea when applied to a low-prevalence setting, current guidelines recommend the use of supplementary polymerase chain reaction (PCR) targeting a different gene for confirmation of true positives in urogenital specimens. This study sought to standardize and evaluate performance of an in-house opa gene-based PCR assay for gonorrhoea compared to assays targeting the porA pseudogene and 16S rRNA gene. Four hundred samples (300 endocervical, 100 urethral swabs) from patients attending STD clinics in New Delhi, India were used. The sensitivity, specificity, positive predictive value and negative predictive value of the opa-based PCR were 100%, 97·9%, 89·5% and 100%, respectively. In females, the use of NAATs provided enhanced diagnosis of gonorrhoea.

Emerging multidrug resistance isolates of hospital-acquired bacterial meningitis in a tertiary care centre in North India.

Purpose. Acute bacterial meningitis continues to be a potentially life threatening condition. Hospital-acquired meningitis is rapidly increasing and adding an immense burden to the health system due to the emergence of multidrug resistance isolates. The purpose of this study is to find the antibiotic susceptibility pattern of the bacteria detected from hospital- and community-acquired meningitis.Methodology. A total of 400 Cerebrospinal fluid (CSF) samples from the suspected meningitis cases were collected and processed for cell count, biochemical examination, Gram staining, latex agglutination and culture. Bacteria grown on blood, chocolate and Mac-conkey agar were identified by matrix-assisted laser desorption/ionization-time of flight. Antibiotic susceptibility tests were performed as per Clinical and Laboratory Standard Institute guidelines.Results. Of the isolates, most prevalent Gram negative organisms in hospital-acquired bacterial meningitis were Escherichia coli 13 (27.08 %), Acinetobacter baumannii 12 (25 %), Klebsiella pneumoniae 5 (10.42 %), Pseudomonas aeruginosa 4 (8.33 %) and Gram positive organisms were Staphylococcus aureus 4 (8.33 %), Enterococcus faecium 3 (6.25 %) and CONS 2 (4.16 %). Streptococcus pneumoniae 3 (6.25 %) was the predominant organism in community-acquired bacterial meningitis. All the Gram negative isolates were multidrug resistance. Only colistin and imipenem were effective antibiotics against them. Likewise Gram positive organisms were susceptible to most of the antibiotics tested. However, E. faecium was only susceptible to Vanco+Teicoplanin.Conclusion. In hospital-acquired bacterial meningitis, multidrug resistance Gram negative bacteria are a huge challenge for the treatment of patients. Hence, antimicrobial stewardship should be followed to counteract with the emerging multidrug resistance isolates.

Clinicoepidemiological profile and predictors of severe illness in young infants (< 60 days) reporting to a hospital in North India.

OBJECTIVES: To describe the clinical and epidemiological profile of young infants reporting to a hospital and assess previously proposed simple clinical signs for their value in enabling health workers to detect young infants with severe illness warranting hospital admission. METHODS: Observational study of infants less than 2 months of age presenting consecutively to a large public hospital in South Delhi who were evaluated by a health worker (nurse), on a standardized list of signs and symptoms, and the ability of these were evaluated against the need for hospital admission which was assessed by an independent pediatrician. RESULTS: Of the 1624 young infants triaged, 878 were enrolled into the study. Of these 100 (11%) were below 7 days of age, for whom the common reasons for seeking care were jaundice (52%), not feeding well (6%) and fever (5%). The remaining 778 (89%) were 7-59 days of age with respiratory symptoms as the main presenting complaints (29.1%). The primary clinical diagnoses in infants with serious illness needing admission to hospital in the age group <7 days (n = 66) were hyperbilirubinemia (56%) and sepsis (21%). In those between 7-27 days of age (n = 60), primary diagnoses were sepsis (27%), pneumonia (13%), diarrhea, dysentery or dehydration (10%), while in the age group 28-59 days of age (n = 47) pneumonia (40%), sepsis (19%) and diarrhea or dehydration (13%) were the common primary diagnoses. Signs that had at least a prevalence of 5% and were strong predictors for all the age categories studied were history of difficult feeding (OR 6.8 for 0-6 days, 15.1 for 2-27 days and 6.2 for 28-59 days age groups), not feeding well on observation (OR 13.7, 27.6 and 20.9 respectively for the 3 age groups), temperature > 37.5C (OR 21.8, 14.6 and 30.0 respectively for the 3 age groups) and respiratory rate > 60 per minute (OR 6.8, 15.1 and 21.0 respectively for the 3 age groups). Additional strong predictors with > 5% prevalence were history of convulsions (OR 7.9, only in 0-6 day age group), lethargy (OR 26.1, only in 7-27 day age group), and history of diarrhea (OR 3.0 for 2-27 days and 2.2 for 28-59 days age groups). CONCLUSIONS: Simple clinical signs are useful in hands of health worker for identifying neonates with serious illness warranting hospital admission. These will be of use in the further development of clinical algorithms for the national integrated management of childhood illnesses.

Roentgenographic and computerized tomography based morphometric analysis of cervical spinal canal diameters to establish normative measurements in an Indian population.

Compressive cervical myelopathy secondary to degenerative changes in the cervical spine is a common cause of neurologic morbidity in the elderly. Identification of canal stenosis and addressing it surgically in addition to the obvious compressive lesions is essential to obtain satisfactory results. We attempt to define the saggital and transverse diameters in a normal adult population presenting at our centre with head injuries. We found that the values were lower than those reported in comparable studies for a western population, and also that the dimensions in women are significantly lower than in men.

Prosthetic joint infection due to Lysobacter thermophilus diagnosed by 16S rRNA gene sequencing.

We report the first case of prosthetic joint infection caused by Lysobacter thermophilus which was identified by 16S rRNA gene sequencing. Removal of prosthesis followed by antibiotic treatment resulted in good clinical outcome. This case illustrates the use of molecular diagnostics to detect uncommon organisms in suspected prosthetic infections.

Coagulase-negative staphylococci causing blood stream infection at an Indian tertiary care hospital: Prevalence, antimicrobial resistance and molecular characterisation.

INTRODUCTION: Recent years have seen a rise of coagulase-negative staphylococci (CoNS) from common contaminants to agents of nosocomial blood stream infections (BSI's). Molecular typing and establishing a correlation with antibiotic resistance is essential particularly in countries like India where genotyping studies for drug-resistant CoNS are sparse. METHODS: A prospective study was done over 18 months, wherein 42,693 blood samples were received, and 59 patients with BSI due to CoNS were evaluated. The isolates recovered were identified by a biochemical test panel and matrix-assisted laser desorption ionization - time of flight mass spectrometry followed by antimicrobial susceptibility testing by Kirby-Baur disc diffusion method and E-test strips. Staphylococcal chromosomal cassette mec (SCCmec) element was characterised by multiplex polymerase chain reaction for all methicillin-resistant (MR) isolates. RESULTS: The majority of CoNS isolated were constituted by Staphylococcus haemolyticus (47.5%) followed by Staphylococcus epidermidis (33.9%), Staphylococcus hominis (11.86%), Staphylococcus cohnii (5.08%) and Staphylococcus warneri (1.69%). Among all isolates 57.6% were MR with statistically significant higher resistance versus methicillin sensitive-CoNS. This difference was significant for erythromycin (76% vs. 44%, P = 0.011), rifampicin (50% vs. 12%,P= 0.002) and amikacin (26.5% vs. 4%, P = 0.023), ciprofloxacin (64.7% vs. 20%, P = 0.001) and cotrimoxazole (55.9% vs. 20%, P = 0.006). SCCmec type I was predominant (61.8%, P = 0.028) and exhibited multidrug resistance (76.2%). Coexistence of SCCmec type I and III was seen in 8.82% MR isolates. CONCLUSION: CoNS exhibit high antimicrobial resistance thereby limiting treatment options. The presence of new variants of SCCmec type in hospital-acquired CoNS may predict the antibiotic resistance pattern. This is the first evaluation of the molecular epidemiology of CoNS causing BSI from India and can serve as a guide in the formulation of hospital infection control and treatment guidelines.

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.

Nosocomial bacteraemia in intensive care unit patients of a tertiary care centre.

Critically ill patients of intensive care units (ICUs) are at particular risk for developing nosocomial bloodstream infections. It is important to know the pathogens causing nosocomial bacteraemia in the ICUs and their antimicrobial sensitivity to formulate appropriate treatment guidelines. We conducted a study from July to December, 2001 in the ICUs of a tertiary care centre in northern India. The records of all the patients who had one or more episodes of nosocomial bacteraemia during the study period were reviewed to identify the pathogens causing bacteraemia and their antimicrobial sensitivities. The source of bacteraemia was ascertained on the basis of a concomitant positive culture from another body site with the same bacteria having a similar antimicrobial sensitivity pattern. A total of 152 episodes of nosocomial bacteraemia occurred in 140 patients. Of these, 148 (97%) episodes were monomicrobial, with Pseudomonas aeruginosa (21%) being the commonest isolate. Overall, Gram negative bacteria accounted for the majority (71%) of isolates. A source of bacteraemia was identified in 49 (32%) episodes, with lower respiratory tract being the commonest (49%) source. A high rate of antimicrobial resistance was observed amongst the isolates, all enterococci having high level aminoglycoside resistance and 89 per cent Gram negative bacteria producing extended spectrum beta-lactamases. A high prevalence of antimicrobial resistance in isolates causing bacteraemia in these critical care wards warrants implementation of strict antibiotic prescribing policies and hospital infection control guidelines.

Aetiological agents for pulmonary exacerbations in children with cystic fibrosis: An observational study from a tertiary care centre in northern India

Background & objectives: Pulmonary disease is the main cause of morbidity and mortality in cystic fibrosis (CF). The infection occurs with a unique spectrum of bacterial pathogens that are usually acquired in an age-dependent fashion. The objective of this study was to find out the aetiological agents in respiratory specimens from children with CF during pulmonary exacerbation and relate with demographic variables. Methods: In this observational study, airway secretions from children (n=104) with CF presenting with pulmonary exacerbations were collected and tested for bacteria, fungi, mycobacteria and viral pathogens using appropriate laboratory techniques. The frequencies of isolation of various organisms were calculated and associated with various demographic profiles. Results: Bacteria were isolated in 37 (35.5%) and viral RNA in 27 (29.3%) children. Pseudomonas was the most common bacteria grown in 31 (29.8%) followed by Burkholderia cepacia complex (Bcc) in three (2.8%) patients. Among viruses, Rhinovirus was the most common, identified in 16 (17.4%) samples followed by coronavirus in four (4.3%). Fungi and mycobacteria were isolated from 23 (22.1%) and four (3.8%) children, respectively. Aspergillus flavus was the most common fungus isolated in 13 (12.5%) children. Interpretation & conclusions: Pseudomonas was the most common organism isolated during exacerbation. Non-tuberculous mycobacteria were not isolated, whereas infection with Bcc and Mycobacterium tuberculosis was observed, which could probably have a role in CF morbidity. Polymicrobial infections were associated with severe exacerbations.

Declining trends of Syphilis seroprevalance among antenatal clinic cases and STD clinic cases in a tertiary care centre: from January 2002 to December 2012.

Syphilis affects nearly 1.36 million pregnant women, majority of these cases being concentrated in the developing countries. We aimed at analysing the 11 years' trends in syphilis seroprevalence in antenatal clinics (ANC) and STD clinic cases. Laboratory data of syphilis cases from 2002-2012 were retrospectively analysed. Out of the total 73,642 cases, 393 (0.53%) tested positive for Syphilis. A statistically significant decline in syphilis prevalence was found in both ANC and STD clinic cases. The efforts of various interventional programs should continue to make the screening and treatment facilities readily accessible to continue the decline in syphilis seropositivity.

Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal.

BACKGROUND: Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10(-18) M,which is far less than what is needed for the survival of the invading bacterial pathogen. To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. RESULTS/ DISCUSSION: Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses four new outer membrane proteins,with molecular weight ranging from 77 kDa to 88 kDa, that are called Iron Regulated Outer Membrane Proteins (IROMPs). We studied the functional and immunological properties of IROMPs expressed by A.baumanii ATCC 19606. The bands corresponding to IROMPs were eluted from SDS-PAGE and were used to immunize BALB/c mice for the production of monoclonal antibodies. Hybridomas secreting specific antibodies against these IROMPs were selected after screening by ELISA and their reactivity was confirmed by Western Blot. The antibodies then generated belonged to IgM isotype and showed bactericidical and opsonising activities against A.baumanii in vitro. These antibodies also blocked siderophore mediated iron uptake via IROMPs in bacteria. CONCLUSION: This proves that iron uptake via IROMPs,which is mediated through siderophores,may have an important role in the survival of A.baumanii inside the host,and helps establishing the infection.

Antihepatotoxic effects of major diterpenoid constituents of Andrographis paniculata.

The diterpenes andrographolide (I), andrographiside (II) and neoandrographolide (III) isolated from Andrographis paniculata were investigated for their protective effects on hepatotoxicity induced in mice by carbon tetrachloride or tert-butylhydroperoxide (tBHP) intoxication. Pretreatment of mice with the diterpenes (I, II & III; 100 mg/kg, i.p.) for 3 consecutive days produced significant reduction in malondialdehyde formation, reduced glutathione (GSH) depletion and enzymatic leakage of glutamic-pyruvate transaminase (GPT) and alkaline phosphatase (AP) in either group of the toxin-treated animals. A comparison with the known hepatoprotective agent silymarin revealed that I exhibited a lower protective potential than II and III, which were as effective as silymarin with respect to their effects on the formation of the degradation products of lipid peroxidation and release of GPT and AP in the serum. GSH status was returned to normal only by III. The greater protective activity of II and III could be due to their glucoside groups which may act as strong antioxidants.

Reduced susceptibility to ciprofloxacin and gyra gene mutation in North Indian strains of Salmonella enterica serotype Typhi and serotype Paratyphi A.

The emergence of reduced susceptibility to ciprofloxacin among Salmonella enterica serotype Typhi and serotype Paratyphi A leading to clinical failure of treatment poses a great therapeutic challenge. The mechanism of fluoroquinolone resistance in clinical isolates of S. Typhi and S. Paratyphi A is not very well documented. The present study was carried out with the objective of molecular characterization of reduced quinolone susceptibility amongst the strains of S. Typhi and S. Paratyphi A isolated from the patients with enteric fever during January, 2000, to April, 2003, in a North Indian hospital. A total of 422 culture-positive cases of enteric fever were reported to the hospital during the period of study, of which S. Typhi was isolated from 350 cases and S. Paratyphi A from 72 cases. The antimicrobial susceptibility of these strains was determined by disk diffusion and agar dilution method according to NCCLS guidelines, and E-test method. A total of 140 randomly selected strains, isolated during the years 1993-1999, that were available from the laboratory stocks were also studied to compare with the present strains. To study the quinolone susceptibility, the strains were divided into nalidixic acid sensitive (NAS), nalidixic acid intermediate resistant, (NAI) and nalidixic acid resistant (NAR) on the basis of susceptibility to nalidixic acid. Clinical history was available from 174 patients, of which 93 needed hospitalization due to severe disease. Of these, 82 patients were infected with NAR strains and 22 patients had a documented evidence of clinical failure to ciprofloxacin therapy. The patients infected with NAR strains were younger and had a significantly longer duration of fever (p value < 0.05) than those infected with NAS strains. It was observed that the proportion of NAR strains increased gradually over the years. These strains had a significantly higher range of MIC of ciprofloxacin (0.023-1.0 microg/ml) as compared to the NAS strains (0.002-0.125 microg/ml) (p value < 0.05). The sequencing of quinolone resistance determining region (QRDR) of the gyrA gene showed the presence of mutation at either Ser 83 or at Asp 87 in all the NAR and NAI strains. None of the NAS strains had a mutation, suggesting that the gyrA gene mutation is sufficient to confer resistance to nalidixic acid and reduced susceptibility to ciprofloxacin. This mutation, although phenotypically expressed as decreased susceptibility to ciprofloxacin, goes undetected by the disk diffusion method using the present NCCLS guidelines. Hence, it can increase morbidity and mortality due to delay in appropriate antibiotic treatment.

Rapid regulation of neurite outgrowth and retraction by phospholipase A2-derived arachidonic acid and its metabolites.

Arachidonic acid and lipoxygenase metabolites have been proposed to act as retrograde synaptic messengers and as early mediators of neuronal injury, but few studies have analyzed their roles in controlling neurite behavior within a time window of minutes to hours. Phospholipase A2 inhibitors (BPB, ONO-RS-082, quinacrine and AACOCF3) and the lipoxygenase inhibitor AA861 delayed the initial outgrowth of NG108-15 cell neurites on laminin. Inhibitors of diacylglycerol lipase (RHC 80267), cyclooxygenase (indomethacin) and free radicals (N-acetyl cysteine and vitamin E) did not produce similar effects. Phospholipase A2 and lipoxygenase inhibitors also prevented acute neurite retraction in response to lysophosphatidic acid and eight other agents tested, and decreased F-actin staining at cell margins. Conversely, exogenous arachidonic acid (1 microM) enhanced the responses of neurites in outgrowth and retraction assays. Phospholipase A2 and lipoxygenase pathways appear to have a general role in maintaining the ability of neurites to respond rapidly to external stimuli, possibly via regulating the ability of the cytoskeleton to remodel.