Omicron variant infection and the associated immunological scenario

The million-dollar question that has been the talk of the day is how effective the COVID 19 vaccines are against the Omicron variant. Still, there is no clear-cut answer to this question but several studies have concluded that this Variant of Concern (VOC) successfully weakens the neutralizing capability of the antibodies acquired from the COVID 19 vaccines and prior infections, which indicates that Omicron can easily bypass an individual’s humoral immune response. However, the most significant confusion revolves around cell-mediated immunity tackling the Omicron variant. This paper aims to provide a clear idea about the status of the body’s immune surveillance concerning the infection caused by the Omicron variant by producing the effectivity of the humoral and cell-mediated immunity in handling the same. This work also provides complete detail of the various characteristics of the Omicron variant and how it may be a blessing in disguise. The effectiveness of the current vaccines, the transmissibility rate of the variant compared to the other variants, and the importance of administering a booster dose to prevent the spread of this variant are also discussed. Finally, this work aims to bridge the gap between the past and the current status of the Omicron infection and sheds light on the hypothetical idea that herd immunity developed from the SARS-COV2 infection may help tackle other dangerous variants.

Identification of extended spectrum beta lactamases, AmpC and carbapenemase production among isolates of Escherichia coli in North Indian tertiary care centre

Introduction:

Identification of Extended spectrum beta lactamases (ESBL), AmpC production and carbapenemase production among isolates of Escherichia coli, helps clinician to rationalize the choice of antibiotics. However, there is a lack of simple and effective method for simultaneous identification of these beta lactamases.

Aim:

To determine the concurrent production of beta lactamases using twelve disc method on E. coli isolates.

Materials and Methods:

A total of 200 multidrug resistant E. coli were screened using twelve disc method. The isolates of ESBL were confirmed by ceftazidime/clavulanic acid and cefotaxime/clavulanic acid method. Metallo-beta-lactamases (MBL) were confirmed by imipenem EDTA combined disc method.

Results:

Among the 200 isolates, 42.5% were ESBL producers, 9% were MBL and 6.5% were Klebsiella pneumoniae carbapenemase (KPC) and AmpC each respectively. Coproduction was seen in 54 (27%). A significant difference in sensitivity was seen in cefuroxime, aztreonam, cefoxitin and ceftriaxone among inpatient and outpatients.

Conclusion:

The present study highlights burden of ESBL, AmpC, KPC and MBL along with their coproduction in a tertiary care hospital. In-house antibiotic policy, infection control and epidemiological surveys will help us in controlling these resistant bugs. We believe, the twelve disc method is a simple, inexpensive screening method for beta lactamase production.

Occupational CNS aspergillosis in an immunocompetent individual a diagnostic challange

INTRODUCTION

Immunocompetent individuals are rarely affected by Aspergillus species and its prime importance lies in immunocompromised patients where it can cause disease, ranging from primarily pulmonary infections to dissemination anywhere in the body. Invasive aspergillosis (IA) occurs in patients with risk factors including prolonged neutropenia, neutrophil dysfunction, patient on cytotoxic drugs, steroid therapy, hematological malignancy, AIDS or in patients with bone marrow transplantation. A recently documented risk factor for IA is the exposure to environmental aspergillus spores at construction sites which makes it an important public health issue. We report here a case of primary CNS aspergillosis in an immunocompetent person who was initially diagnosed as a case of meningioma, and had a history of working in an area with excessive ongoing construction. He had no other primary focus of infection anywhere in the body. He was timely diagnosed and broad spectrum antifungals were started immediately.

MATERIAL AND METHODS

The brain biopsy and pus sampleas were subjected to direct microscopy using KOH mount and lactophenol cotton blue (LPCB) stain and culture on Sabourad's Dextrose Agar in Microbiology laboratory. Later patient was started on fluconazole and caspofungin.

RESULTS

Thin, hyaline, septate hyphae on direct microscopy and growth of Aspergillus flavus on SDA culture were observed. The patient improved only with antifungals, without surgery.

DISCUSSION

This case study highlights the importance of keeping the differential diagnosis of Aspergillus spp. in mind even in individuals with no immunodeficiency. The immunocompetent individuals have better prognosis and if timely diagnosed, can be treated even without surgery. The prevalence of aspergillus spores at construction and demolition sites makes it an important public health issue, hence precautions must be advocated at these sites.

Prevalence of biofilm producing aerobic bacterial isolates in burn wound infections at a tertiary care hospital in northern India

Burn wounds frequently get infected due to a break in skin integrity and prolonged hospitalization. Microbial flora originating from the patient's own flora colonize and infect the burn wounds. Bacterial biofilms in particular are postulated as the culprit for the development of non-healing burn wounds by inducing chronic inflammation in these patients. In the present study, 190 wound isolates obtained from patients admitted to the burn ward at the Pt. B.D. Sharma PGIMS, Rohtak, were evaluated for biofilm formation along with Antimicrobial Susceptibility Testing (AST). Biofilm detection was done by modified Tissue Culture Plate method and AST was done by Kirby-Bauer disc diffusion method. A total of 190 isolates were studied, which included Staphylococcus aureus, Coagulase negative Staphylococcus, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella spp., Proteus spp., Citrobacter spp., Escherichia coli and Enterobacter spp. Of these, 68.9% isolates showed biofilm formation. Biofilm formation was more common in Pseudomonas aeruginosa followed by Klebsiella spp. and Staphylococcus aureus. Biofilm producing isolates showed greater multidrug resistance than non-biofilm producers. In our study, a high rate of biofilm formation and antimicrobial drug resistance was seen.

Comparison of four different methods for detection of biofilm formation by uropathogens

CONTEXT

Urinary tract infection (UTI) is one of the most common infectious diseases encountered in clinical practice. Emerging resistance of the uropathogens to the antimicrobial agents due to biofilm formation is a matter of concern while treating symptomatic UTI. However, studies comparing different methods for detection of biofilm by uropathogens are scarce.

AIMS

To compare four different methods for detection of biofilm formation by uropathogens.

SETTINGS AND DESIGN

Prospective observational study conducted in a tertiary care hospital.

MATERIALS AND METHODS

Totally 300 isolates from urinary samples were analyzed for biofilm formation by four methods, that is, tissue culture plate (TCP) method, tube method (TM), Congo Red Agar (CRA) method and modified CRA (MCRA) method.

STATISTICAL ANALYSIS

Chi-square test was applied when two or more set of variables were compared. P < 0.05 considered as statistically significant. Considering TCP to be a gold standard method for our study we calculated other statistical parameters.

RESULTS

The rate of biofilm detection was 45.6%, 39.3% and 11% each by TCP, TM, CRA and MCRA methods, respectively. The difference between TCP and only CRA/MCRA was significant, but not that between TCP and TM. There was no difference in the rate of biofilm detection between CRA and MCRA in other isolates, but MCRA is superior to CRA for detection of the staphylococcal biofilm formation.

CONCLUSIONS

TCP method is the ideal method for detection of bacterial biofilm formation by uropathogens. MCRA method is superior only to CRA for detection of staphylococcal biofilm formation.

Role of Non Albicans Candida Spp. and Biofilm in Neonatal ICU

BACKGROUND

Candida spp. remains the fungal species most commonly associated with biofilm formation. Increase in Candida infections in last decades has almost paralleled the increase and wide spread use of a broad range of medical implant devices mainly in population with impaired host defences. One of the most important characteristics of biofilms is their high level of resistance to antimicrobial drugs.

AIMS AND OBJECTIVES

This study was conducted to know the prevalence of different Candida spp. causing blood stream infections and ability to form biofilm and to evaluate the co relation of biofilm with antifungal drug resistance.

MATERIAL AND METHODS

The present study was conducted on 12464 blood samples for the identification and speciation of various Candida spp. causing blood stream infection over a period of one year. Antifungal susceptibility was performed as per clinical laboratory standard institute guidelines and biofilm formation was detected by method described by Christensen's et al.

RESULTS

Out of total 12464 blood culture received, 1378 (11.05%) were culture positive rest and among culture positive 100 (7.25%) Candida isolates were recovered. C. tropicalis was the commonest (43%) species followed by C. albicans (41%), C. krusei (9%) and C. parapsilosis (7%). A total of 41 Candida isolates were biofilm producers and rest 59 isolates were non-biofilm producers.

CONCLUSION

A changing trend of increased prevalence of non albicans Candida spp. was observed which were resistant to commonly used antifungal fluconazole. Multi drug resistance was more common in biofilm forming Candida isolates.

Acinetobacter lwoffii an emerging pathogen in neonatal ICU

BACKGROUND

Acinetobacter species are ubiquitous in the environment and are important causative agent for nososcomial infection especially in immunocompromised patients. Multi drug resistant Acinetobacter lwoffii are emerging as a pathogen in neoanatal sepsis.

AIMS AND OBJECTIVE

This study was aimed to evaluate the clinical and antibiotic profile of Acinetobacter lwoffii.

MATERIAL AND METHODS

This study was done on blood samples from neonates admitted to neonatal intensive care unit during a period of one year from January to December 2012, who developed Acinetobacter infection. The diagnosis of isolates and antibiotic susceptibility testing was done by both conventional as well as by automated system.

RESULTS

Out of total 13,133 blood samples received for culture, 1418(10.8%) were from NICU. Ninety (6.3%) isolates were found to be positive for the growth of Acinetobacter species. Of these isolates 31.11% were found to be Acinetobacter lwoffii, 68.9% were Acinetobacter baumannii calcaetius complex. Acinetobacter lwoffii isolates were most commonly sensitive to imepenem 16(57%), cotrimoxazole 9(32%), ciprofloxacin 6(21%) followed by amoxyclavulanic acid 2(7%) and cefuroxime 1(3.5%).

CONCLUSION

Multi drug resistant Acinetobacter lwoffii infection is increasing particularly in premature and very low-birth weight neonates. Judicious and timely antibiotic use in NICUs are one of the important key in controlling multi-drug resistant Acinetobacter infection and improving clinical outcome.

Brain-computer interfaces in the completely locked-in state and chronic stroke

Brain-computer interfaces (BCIs) use brain activity to control external devices, facilitating paralyzed patients to interact with the environment. In this chapter, we discuss the historical perspective of development of BCIs and the current advances of noninvasive BCIs for communication in patients with amyotrophic lateral sclerosis and for restoration of motor impairment after severe stroke. Distinct techniques have been explored to control a BCI in patient population especially electroencephalography (EEG) and more recently near-infrared spectroscopy (NIRS) because of their noninvasive nature and low cost. Previous studies demonstrated successful communication of patients with locked-in state (LIS) using EEG- and invasive electrocorticography-BCI and intracortical recordings when patients still showed residual eye control, but not with patients with complete LIS (ie, complete paralysis). Recently, a NIRS-BCI and classical conditioning procedure was introduced, allowing communication in patients in the complete locked-in state (CLIS). In severe chronic stroke without residual hand function first results indicate a possible superior motor rehabilitation to available treatment using BCI training. Here we present an overview of the available studies and recent results, which open new doors for communication, in the completely paralyzed and rehabilitation in severely affected stroke patients. We also reflect on and describe possible neuronal and learning mechanisms responsible for BCI control and perspective for future BMI research for communication in CLIS and stroke motor recovery.

Case Report: Escherichia fergusonnii - Pathogen in Urinary Tract Infection

Urinary tract infections are one of the leading cause of morbidity in admitted patients. Most commonly caused by Escherichia coli, but there are some variants which are commonly reported in urinary tract infection. This study was about to speciate such isolate like E.fergusonnii and find out its antibiogram.

Study of virulence factors of uropathogenic Escherichia coli and its antibiotic susceptibility pattern

CONTEXT

Urinary tract infection (UTI) is one of the most common nosocomial infections, caused by Escherichia coli. This study determined the presence of virulence factors in the organism and correlates it with the multi-drug resistance (MDR).

AIMS

The aim of the following study is to assess the virulence factors of uropathogenic E. coli and antibiotic susceptibility pattern.

SETTINGS AND DESIGN

This was a prospective study conducted in the Department of Microbiology in PT. B. D. Sharma, PGIMS, Rohtak.

SUBJECTS AND METHODS

The study was conducted over a period of 1 year. Urine samples received were processed as per standard microbiological procedures. Virulence factors such as hemolysin, hemagglutination, cell surface hydrophobicity, serum resistance, gelatinase and siderophore production were studied. The antimicrobial susceptibility was done as per Clinical and Laboratory Standard Institute Guidelines.

STATISTICAL ANALYSIS USED

The data was analyzed by using SPSS(Statistical Package for the social sciences) IBM Corporation version 17.0. A two sided P ≤ 0.05 was considered to be significant.

RESULTS

Hemolysin production was seen in 47.4%, hemagglutination in 74.8%, cell surface hydrophobicity in 61%, serum resistance in 59%, gelatinase in 67.5% and siderophore production in 88% isolates. Nitrofurantoin was found to be most effective followed by, gatifloxacin and gentamicin. Twenty nine percent (29.62%) isolates were MDR.

CONCLUSIONS

Therefore, the knowledge of virulence factors of E. coli and their antibiotic susceptibility pattern will help in better understanding of the organism and in the treatment of UTI.

Biofilm and multidrug resistance in uropathogenic Escherichia coli

CONTEXT

Escherichia coli is known as causative agent of urinary tract infections (UTIs) tends to form microcolonies in mucosa lining of urinary bladder known as biofilm. These biofilms make the organism to resist the host immune response, more virulent and lead to the evolution of antibacterial drug resistance by enclosing them in an extracellular biochemical matrix.

AIMS

This study was done to know the association of various virulence factors and biofilm production in uropathogenic E. coli (UPEC) and antibiotic susceptibility pattern.

SETTINGS AND DESIGN

This study was conducted in Pt. B.D. Sharma PGIMS, Rohtak, Haryana during a period of 1 year from January 2011 to December 2011.

METHODS AND MATERIAL

Biofilm was detected by microtiter plate (MTP) method, and various virulence factors like hemolysin, hemagglutination, gelatinase, siderophore production, serum resistance, and hydrophobicity were detected. The antibiotic susceptibility testing was done by modified Kirby-Bauer disk diffusion and the disk diffusion method was used to confirm the ESBL, AmpC, MBL production by the UPEC statistical analysis used: The data were analyzed by using SPSS version 17.0. A two-sided P-value of less than or equal to 0·05 was considered to be significant.

RESULTS

Biofilm production was found in 18 (13·5%) isolates, more commonly in females (two times). These isolates were found to be resistant to antibiotics common in use and were 100% MDR.

CONCLUSIONS

Biofilm production makes the organism to be more resistant to antibiotics and virulent as compared to non-biofilm producers.

Brain-machine interface (BMI) in paralysis

INTRODUCTION

Brain-machine interfaces (BMIs) use brain activity to control external devices, facilitating paralyzed patients to interact with the environment. In this review, we focus on the current advances of non-invasive BMIs for communication in patients with amyotrophic lateral sclerosis (ALS) and for restoration of motor impairment after severe stroke.

BMI FOR ALS PATIENTS

BMI represents a promising strategy to establish communication with paralyzed ALS patients as it does not need muscle engagement for its use. Distinct techniques have been explored to assess brain neurophysiology to control BMI for patients' communication, especially electroencephalography (EEG) and more recently near-infrared spectroscopy (NIRS). Previous studies demonstrated successful communication with ALS patients using EEG-BMI when patients still showed residual eye control, but patients with complete paralysis were unable to communicate with this system. We recently introduced functional NIRS (fNIRS)-BMI for communication in ALS patients in the complete locked-in syndrome (i.e., when ALS patients are unable to engage any muscle), opening new doors for communication in ALS patients after complete paralysis.

BMI FOR STROKE MOTOR RECOVERY

In addition to assisted communication, BMI is also being extensively studied for motor recovery after stroke. BMI for stroke motor recovery includes intensive BMI training linking brain activity related to patient's intention to move the paretic limb with the contingent sensory feedback of the paretic limb movement guided by assistive devices. BMI studies in this area are mainly focused on EEG- or magnetoencephalography (MEG)-BMI systems due to their high temporal resolution, which facilitates online contingency between intention to move and sensory feedback of the intended movement. EEG-BMI training was recently demonstrated in a controlled study to significantly improve motor performance in stroke patients with severe paresis. Neural basis for BMI-induced restoration of motor function and perspectives for future BMI research for stroke motor recovery are discussed.

Fosfomycin use in multi drug resistant uropathogenic Escherichia coli

OBJECTIVES AND AIMS

Escherchia coli isolated, from urine samples were studied for their antibiotic susceptibility patterns, with special reference to the new antimicrobial compound fosfomycin and their correlation with various virulence factors.

MATERIAL AND METHODS

The mid stream urine samples received in the department were processed and identification was done by using the standard culture and identification techniques. The antibiotic susceptibility testing was done by modified Kirby-Bauer disk diffusion and the disk diffusion method was used to confirm the ESBL, AmpC, MBL production by the UPEC. Various virulence factors like hemolysin, haemagglutinaton, gelatinase, siderophore production, biofilm formation, serum resistance and hydrophobicity were detected.

RESULTS

Fosfomycin was found to be most effective agent (100%) against uropathogenic E.coli followed by netilmicin (89.5%). The least effective agents were ampiciilin and cotrimoxazole. Twenty nine percent (29%) isolates were found to be multi drug resistant (MDR).

CONCLUSIONS

The testing of the newer therapeutic agents like fosfomycin will add on to therapeutics for UTI's.

Changing trends of Candidemia and antifungal susceptibility pattern in a tertiary health care centre

BACKGROUND

Bloodstream infections (BSI) caused by various Candida spp. are a significant cause of morbidity and mortality in hospitalized patients. An increasing proportion of device- related infections, particularly those involving the bloodstream and urinary tract, are being caused by Candida spp.

AIMS AND OBJECTIVES

This study was conducted to evaluate the different species of Candida causing blood stream infections and their antifungal susceptibility.

MATERIAL AND METHODS

The present study was conducted on 12464 blood samples received for culture, the samples were incubated at 37ºC for overnight and inoculated on culture plate next day. The growth on culture plates was identified by standard microbiological techniques and their antifungal susceptibility was put up as per Centre for Laboratory Standard Institute guidelines.

RESULTS

Out of 12464 blood samples, isolation rate of Candida spp was 7.25%, which was higher in paediatric age group patients (89%) as compared to adults (11%). BSIs due to Candida spp. was significantly more common among ICUs (72%) than non-ICU settings (28%). C. tropicalis was the commonest (43%) species isolated followed by C. albicans (41%), C. krusei (9%) and C. parapsilosis (7%). All strains were 100% sensitive to Amphotericin B.

CONCLUSION

There is a changing trend of increased isolation of non albicans Candida spp. than Candida albicans. It was common in ICUs settings and in paediatric age group. All isolates were found 100% sensitive to Amphotericin-B, C.krusei was 100% resistant to fluconazole followed by C. tropicalis 32.6% and C. parapsilosis 28.58%.

Comparison of ELISA and Microscopy for detection of Cryptosporidium in stool

BACKGROUND

Cryptosporidiosis, a diarrheal disease caused by the protozoan parasite Cryptosporidium spp. has become recognized as one of the most common causes of water borne diseases in humans.

AIMS AND OBJECTIVES

To compare the sensitivity of ELISA and Microscopy for detection of Cryptosporidium in stool samples Materials and Methods: The study was conducted in the Department of Microbiology of PT. B.D. Sharma PGIMS Rohtak, between January 2011 to june 2011 on 50 stool samples, which were processed for detection of cryptosporidial antigen by ELISA and detection of cysts by microscopy (Modified Ziehl and Nelsen staining).

STUDY AND DESIGN

This was a prospective study conducted in the Department of Microbiology in PT. BD Sharma, PGIMS, Rohtak, India.

RESULT

Out of total, 50 stool samples eighteen (36%) samples were found positive for Cryptosporidium cysts by microscopy in comparison to 3(6%) stool samples which were found positive for cryptosporidial antigen by ELISA. Samples found positive with ELISA were also positive with microscopy. Sensitivity, specificity, positive predictive value and negative predictive value for ELISA was 16.7%, 100%, 100% and 68% respectively.

CONCLUSION

The study concludes that stool microscopic Modified acid fast staining is more sensitive method than ELISA for detection of Cryptosporidium in stool samples but the specificity of ELISA was more than microscopy.

Ventilator-associated pneumonia in a tertiary care intensive care unit: Analysis of incidence, risk factors and mortality

Background:

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection diagnosed in the intensive care unit (ICU) and in spite of advances in diagnostic techniques and management it remains a common cause of hospital morbidity and mortality.

Objective:

The primary objective of the following study is to determine the incidence, various risk factors and attributable mortality associated with VAP and secondary objective is to identify the various bacterial pathogens causing VAP in the ICU.

Materials and Methods:

This prospective observational study was carried out over a period of 1 year. VAP was diagnosed using the clinical pulmonary infection score. Endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) samples of suspected cases of VAP were collected from ICU patients and processed as per standard protocols.

Statistical Analysis:

Fisher's exact test was applied when to compare two or more set of variables were compared.

Results:

The incidence of VAP in our study was 57.14% and the incidence density of VAP was 31.7/1000 ventilator days. Trauma was the commonest underlying condition associated with VAP. The incidence of VAP increased as the duration of mechanical ventilation increased and there was a total agreement in bacteriology between semi-quantitative ETAs and BALs in our study. The overall mortality associated with VAP was observed to be 48.33%.

Conclusions:

The incidence of VAP was 57.14%. Study showed that the incidence of VAP is directly proportional to the duration of mechanical ventilation. The most common pathogens causing VAP were Acinetobacter spp. and Pseudomonas aeruginosa and were associated with a high fatality rate.

Co-production of ESBL and AmpC β-Lactamases in Clinical Isolates of A. baumannii and A. lwoffii in a Tertiary Care Hospital From Northern India

BACKGROUND

Acinetobacter baumannii is an important cause of health care associated infections which are difficult to control and treat, because of widespread antimicrobial resistance which is possessed by this organism.

AIMS

The aim of the present study was to know the prevalence of ESBLs and AmpC β-lactamases in clinical isolates of Acinetobacter spp. which were cultured from various clinical specimens by using different phenotypic methods.

SETTINGS AND DESIGN

Study was conducted over a period of one year at the Microbiology Department of a tertiary care teaching hospital. A total of 100 consecutive, non-duplicate strains of Acinetobacter species which were isolated from various clinical samples were included.

MATERIALS AND METHODS

All the isolates were identified by standard microbiological procedures and antimicrobial susceptibility testing was done by Kirby-Bauer disc diffusion technique. Isolates which showed reduced susceptibilities to third generation cephalosporins were tested for ESBL production by CLSI double disc synergy method and also by using sulbactam as an inhibitory agent. Isolates which showed reduced susceptibilities to cefoxitin were tested for AmpC detection by doing AmpC disc test.

STATISTICAL ANALYSIS

SPSS, version 17 was used to calculate p-value. If the p-value was <0.05, it was considered to be significant.

RESULTS

Out of 100 isolates, 82 were Acinetobacter baumannii and 18 were Acinetobacter lwoffii. ESBL were mentioned in 4% of the Acinetobacter isolates and in 77% of the isolates by using clavulanic acid and sulbactam as inhibitory agents respectively. AmpC β-lactamase production was detected in 60% isolates of Acinetobacter spp. Co-production of both ESBL and AmpC enzymes were seen in 29% of the Acinetobacter strains.

CONCLUSION

Failure in detecting β-lactamases contributes to their uncontrolled spread and therapeutic failures. Hence, these β-lactamases should be detected routinely and they should be reported to clinicians in time, so that inappropriate use of antibiotics can be stopped in time.

Emergence of nonalbicans Candida in neonatal septicemia and antifungal susceptibility: experience from a tertiary care center

Aims:

To know the distribution and antifungal susceptibility pattern of Candida species in neonatal septicemia cases.

Materials and Methods:

In a prospective analysis blood samples from 825 clinically suspected cases of neonatal septicemia, collected aseptically, were cultured to look for the role of Candida spp. in septicemia. Candida isolates were speciated by germ tube test, Hi-CHROME agar, sugar fermentation, and sugar assimilation tests using standard protocol. All the Candida isolates were tested for antifungal susceptibility to fluconazole by the Disk Diffusion (DD) method and broth micro dilution-minimum inhibitory concentration (BMD-MIC) method using NCCLS guidelines.

Results:

Isolation rate of Candida from neonatal septicemia cases was 8.1%. Most common isolate was C. tropicalis (61.19%), followed by C. albicans (19.40%), C. glabrata (11.94%), C. parapsilosis (5.97%) and C. guillermondii (1.49%). Low birth weight and previous antibiotic prophylaxis was found in 100% cases. Crude mortality rate was 50.1%. By DD method, 95.53% of the Candida isolates were sensitive to fluconazole. A discrepancy between DD method and BMD-MIC method was noted in 4.47% strains. One isolates each of C. tropicalis, C. albicans, and C. glabrata showed discrepancy.

Conclusion:

Nonalbicans Candida has emerged as an important cause of neonatal septicemia. Routine susceptibility testing of Candida isolates by DD method should be confirmed by BMD-MIC method. Fluconazole can be used as empirical therapy for neonatal candidemia at our center.

Changing trend of antimicrobial resistance among gram-negative bacilli isolated from lower respiratory tract of ICU patients: A 5-year study

Background:

Lower respiratory tract infections (LRTIs) are the most frequent infections among patients in intensive care units (ICUs).

Aim:

To track the resistance rate among the causative agents causing LRTI in the ICU patients.

Design and Settings:

This is a retrospective study done in a tertiary care hospital.

Materials and Methods:

Transtracheal or bronchial aspirates from 2776 patients admitted to the ICU were cultured and identified, and antibiotic sensitivity was performed by standard methods.

Results:

Of 2776 specimens, 1233 (44.41%) isolates were recovered, of which 1123 (91.07%) were gram-negative bacilli (GNB) and 110 (8.92%) were gram-positive organisms. From 2004 to 2009, Pseudomonas aeruginosa remained the most common pathogen. In phase I, high level of resistance (79–98%) was observed against all GNB. During phase II increasing trend in resistance to cephalosporins and declining trend in resistance to aminoglycosides against most GNB were observed. Multidrug resistance (resistance to three or more than three drugs) was observed in 83% of total isolates.

Conclusions:

Gram-negative organisms are the predominant pathogens causing LRTI in ICU. The increasing trend of resistance to cephalosporins and carbapenems in gram-negative organisms is very disturbing. Judicious use of antimicrobial agents is essential to prevent the emergence of multidrug-resistant bacteria in the ICU.

Metallo-beta-lactamase Producing Pseudomonas aeruginosa in Neonatal Septicemia

Gram-negative bacilli are important agents causing neonatal sepsis. The organisms isolated are often resistant to multiple antimicrobials specially which are metallo-beta-lactamases (MβL) producers. Therefore, the present study was conducted with the objective to examine the incidence of MβL producing strains in multidrug resistant (MDR) Pseudomonas aeruginosa from cases of neonatal sepsis. Between January-December 2006, 1994 cases of neonatal sepsis were investigated. The isolates obtained were identified and tested for susceptibility to various antimicrobial agents. The multidrug resistant P. aeruginosa isolates were screened for the presence of MβL by imipenem-EDTA disc method. Five hundred and ninety three (29.73%) isolates were obtained from culture of neonates. Most frequent offender was P. aeruginosa (48.2%). There was an overall predominance of gram-negative organisms. MβL production was seen in 69.5% of imipenem-resistant P. aeruginosa isolates. MβL producing P. aeruginosa is an emerging threat in neonatal septicemia and a cause of concern for physicians treating such infections.

Detection of Extended Spectrum β-lactamase Production Among Uropathogens

Background:

Detection of extended spectrum β-lactamase (ESBL) production among uropathogens is an important marker of endemicity.

Aim:

Intervention of this endemic transmission is important for the control of initial outbreak of ESBL producing organisms in a hospital or specialized unit of hospital.

Materials and Methods:

During the study period of one and a half months, 1,551 urine samples were processed for significant bacteriuria. Two hundred gram negative bacterial isolates were tested for ESBL production. Antimicrobial sensitivity pattern was ascertained for ESBL producing isolates.

Results:

ESBL production was seen in 36% of isolates. All the isolates were multidrug resistant with uniform sensitivity to imipenem.

Conclusion:

This study reveals the significant prevalence of ESBL producing organisms in this north Indian tertiary care hospital. Constant revision of antibiotic policies with infection control interventions is suggested.

Risk factors associated with low birth weight

BACKGROUND

Babies with a birth weight of less than 2500 grams, irrespective of the period of their gestation are termed as Low Birth Weight (LBW) babies. Despite consistent efforts to improve the quality of maternal and child health, more than twenty million low birth-weight (LBW) babies are born every year throughout the world. Though, the health situation of Nepal has improved substantially over the years, the low birth-weight (LBW) rate still high. The present study was to explore the effects of various maternal risk factors associated with low birth-weight of institutionally delivered newborns.

METHODS

A cross sectional hospital based study was conducted in Obstetrics and Gynaecology ward of Janakpur Zonal Hospital, Janakpur, Nepal from December 2009 to January 2010. Altogether 306 respondents were taken and respondents were mothers who have delivered newborns in hospital.

RESULTS

A total of 1426 birth occurred during the study period (December 2009 to January 2010), of which 306 met the study criteria. Among which 66 (21.56%) were low birth weight (LBW) and 240 were normal birth weight (NBW). Overall mean birth weight was found to be 2.75 ± 0.639 kg. Out of total 21.56% newborns were weighing less than 2.50 kg and mean birth weight was 1.96 ± 0.409 kg. The study also shows that majority 73 (86%) of the research centers didn't start the research yet.

CONCLUSIONS

This study suggests that there are several factors interplaying which lead to LBW babies. Socio-demographic factors (maternal age, educational level and economic status) and antenatal care are more important.

Quorum sensing and Bacterial Pathogenicity: From Molecules to Disease

Quorum sensing in prokaryotic biology refers to the ability of a bacterium to sense information from other cells in the population when they reach a critical concentration (i.e. a Quorum) and communicate with them. The “language” used for this intercellular communication is based on small, self-generated signal molecules called as autoinducers. Quorum sensing is thought to afford pathogenic bacteriaa mechanism to minimize host immune responses by delaying theproduction of tissue-damaging virulence factors until sufficientbacteria have amassed and are prepared to overwhelm host defensemechanisms and establish infection. Quorum sensing systems are studied in a large number of gram-negative bacterial species belonging to α, β, and γ subclasses of proteobacteria. Among the pathogenic bacteria, Pseudomonas aeruginosa is perhaps the best understood in terms of the virulence factors regulated and the role the Quorum sensing plays in pathogenicity. Presently, Quorum sensing is considered as a potential novel target for antimicrobial therapy to control multi/all drug-resistant infections. This paper reviews Quorum sensing in gram positive and gram negative bacteria and its role in biofilm formation.

Evaluation of microbiocidal activity of superoxidized water on hospital isolates

BACKGROUND

Prevention of nosocomial infections, pre-operative and post-operative complications is directly linked with effective disinfection and decontamination. Microbial decontamination is the most serious challenge to the today's health care practice despite the abundance of disinfectants and chemicals as there are increasing reports of emergence of resistance to the action of commonly used disinfectants. There is a need to evaluate the efficacy of newer methods of asepsis for better patient management.

AIM

This study was designed to evaluate the microbiocidal activity of superoxidized water (SOW) on common clinical isolates, ATCC strains, vegetative cells and spores of Bacillus subtilis.

MATERIALS AND METHODS

Bacterial suspensions were treated with SOW and deionized water (control). All the tubes were incubated at 37°C for 0.5, 2.5 and 5.0 min. The number of viable cells was counted.

RESULTS

All the clinical isolates and ATCC strains were killed within 0.5 min of exposure to the SOW. Vegetative cells and spores of B. subtilis were killed after 5.0 min.

CONCLUSION

We conclude that SOW is an effective microbiocidal agent for routine hospital use.

Ten days vs. 14 days antibiotic therapy in culture-proven neonatal sepsis

BACKGROUND

There are no evidence-based guidelines for the treatment of neonatal sepsis although standard text books recommend 14 days of antibiotics for blood culture-proven neonatal sepsis.

OBJECTIVE

The present study compared the effectiveness of a 10-day course of antibiotic therapy with the conventional 14-day course in blood culture-proven neonatal sepsis.

METHODS

Infants ≥ 32 weeks and ≥ 1.5 kg weight with blood culture-proven sepsis were randomized to either 10-day (study group) or 14-day (control group) therapy on Day 7 of appropriate antibiotic therapy, if they were in clinical remission and were C-Reactive Protein (CRP) negative. The primary outcome was treatment failure within 28 days defined by either positive CRP or positive blood culture or clinical relapse.

RESULTS

The baseline characteristics were comparable between the two groups. There was one treatment failure in each group. The duration of hospital stay was significantly shorter in the 10-day treatment group.

CONCLUSION

Ten-day antibiotic therapy is as effective as 14-day therapy in blood culture-proven neonatal sepsis, if the infant has achieved clinical remission by Day 7 of therapy.

Antibiotic sensitivity pattern of gram negative bacilli isolated from the lower respiratory tract of ventilated patients in the Intensive care unit

Background:

Lower respiratory tract infections (LRTIs) are the most frequent infections among patients in Intensive care units (ICUs).

Aims:

To know the bacterial profile and determine the antibiotic susceptibility pattern of the lower respiratory tract isolates from patients admitted to the ICU.

Settings and Design:

Tertiary care hospital, retrospective study.

Materials and Methods:

Transtracheal or bronchial aspirates from 207 patients admitted to the ICU were cultured, identified, and antibiotic sensitivity was performed by standard methods.

Statistical Analysis Used:

SPSS software was used for calculation of % R of 95% confidence interval (CI).

Results:

Of 207 specimens, 144 (69.5%) were culture positive and 63 (30.4%) showed no growth. From 144 culture positives, 161 isolates were recovered, of which 154 (95.6%) were Gram negative bacilli (GNB). In 17 (11.0%) patients, two isolates per specimen were recovered. The most common GNB in order of frequency were Pseudomonas aeruginosa (35%), Acinetobacter baumannii (23.6%), and Klebsiella pneumoniae (13.6%). A very high rate of resistance (80-100%) was observed among predominant GNB to ciprofloxacin, ceftazidime, co-trimoxazole, and amoxycillin/clavulanic acid combination. Least resistance was noted to meropenem and doxycycline.

Conclusion:

Nonfermenters are the most common etiological agents of LRTIs in ICU. There is an alarmingly high rate of resistance to cephalosporin and β-lactam-β-lactamase inhibitor group of drugs. Meropenem was found to be the most sensitive drug against all GNB. Acinetobacter and Klebsiella spp. showed good sensitivity to doxycycline.

QUALITY OF LIFE IN MEN WITH LOCALIZED PROSTATE CANCER TREATED BY RADICAL PROSTATECTOMY OR RADIOTHERAPY

Radical prostatectomy and radiotherapy are the most commonly utilized modalities for managing patients with localized prostate cancer. Each has effects on quality of life that are important in decision making. Long term side effects of these treatment modalities include urinary, bowel and sexual dysfunction, and have been documented. Comparison of the side effects of these different modalities continues to be explored, emphasizing their effects on quality of life (QOL) from the patient's viewpoint. Questionnaires were mailed to 224 eligible patients and a response was elicited in 161 men (72%). The final number of patients who completed all the questionnaires was 151. Of these, 73 (48%) had radical prostatectomy and 78 (52%) had radiotherapy. General well being measures demonstrated a definite advantage favoring men treated with radical prostatectomy. Prostate cancer specific QOL measures were similar among men treated with surgery or radiotherapy. Radiotherapy treated men were slightly more likely to report bowel-related problems than surgically treated men. Urinary QOL measures were no different between treated groups. Surgically treated men reported lower level of sexual function than radiotherapy treated men.

Lymphadenopathy--An Important Guiding Tool for Detecting Hidden HIV-Positive Cases: A 6-Year Study

Lymphadenopathy is one of the leading and persistent signs during the progression of human immunodeficiency virus (HIV) infection. Lymphadenopathy, as a clinical sign, can become one of the important guiding tools for detecting hidden HIV-positive cases. The present study was conducted to assess the incidence of HIV positivity in previously undiagnosed patients of HIV presenting with lymphadenopathy, comparing it with the current trends of HIV infection in the community, and to ascertain the etiology of lymphadenopathy in HIV-positive and HIV-negative cases. Over a period of 6 years, a total of 1082 cases of extra-inguinal lymphadenopathy were screened for HIV infection. Simultaneously, fine needle aspiration cytology of the enlarged lymph nodes was performed to know the etiology. The incidence of HIV positivity was found to be 2.3% among the patients presenting with lymphadenopathy. Among the HIV-positive cases, tuberculous lymphadenopathy was found in 60% of cases as compared to 28% of cases in HIV-negative cases. Alarmingly high incidence of HIV infection among the lymphadenopathy cases has been observed. This necessitates the importance of exercising vigilance, caution, and a high degree of suspicion while dealing with patients of lymphadenopathy, to protect ourselves as well as a much larger population at risk from this scourge.

Superior vena cava syndrome caused by pulmonary amoebic abscess

Isolated pulmonary amoebiasis without involvement of liver and other systems is extremely rare. Its presentation with superior vena cava (SVC) syndrome is not well documented. The case of 38-year-old male who developed SVC syndrome due to a large pulmonary amoebic abscess, which initially mimicked a pulmonary neoplasm with distal lung abscess is presented here. Subsequent bacteriological examination of the aspirated pus and the sputum along with suggestive serology confirmed the diagnosis of pulmonary amoebic abscess.

Extended spectrum -lactamases (ESBL) - an emerging threat to clinical therapeutics

Extended spectrum -lactamases (ESBLs) are plasmid mediated, TEM and SHV derived enzymes, first isolated in Western Europe in mid 1980s, most commonly in Klebsiella spp., followed by Escherichia coli. These enzymes are capable of hydrolyzing broad spectrum cephalosporins and monobactams but inactive against cephamycins and imipenem. In addition, ESBL producing organisms exhibit coresistance to many other classes of antibiotics resulting in limitation of therapeutic option. Several risk factors have been suggested. A variety of classification schemes have been developed. Recently, Bush-Jacoby-Medeiros scheme integrated functional and molecular characteristics. ESBLs have serine at their active site and attack the amide bond in the lactam ring of antibiotics causing their hydrolysis. Because of inocolum effect and substrate specificity their detection is a major challenge. Two indicators of ESBLs are eight fold reduction in MIC and potentiation of the inhibitor zone of third generation cephalosporin in the presence of clavulanic acid. Incidence of these organisms is being continuously increasing through out the world with limited treatment alternatives. It becomes necessary to know the prevalence of these organisms and to formulate treatment policy. Moreover, restricted use of the third generation cephalosporins lead to withdrawal of selective pressure and use of lactam and -lactamase inhibitor combinations may exert reverse mutation on these enzymes.

Sensitivity pattern of Salmonella serotypes in Northern India

BACKGROUND

Enteric fever continues to be a major public health problem, especially in the developing countries of the tropics. We determined the incidence of Salmonella bloodstream infections and their antimicrobial resistance patterns from May to August in the years 1997-2001 in Haryana, a large state of India. The minimum inhibitory concentration (MIC) was also determined for 60 isolates of S. typhi to various commonly used antimicrobial agents.

MATERIAL AND METHODS

Blood cultures of 6,956 patients (PUO/septicemia) were processed by standard procedures and the Salmonella spp. isolates were identified with specific antisera and with standard biochemical tests. Antimicrobial susceptibilities were determined by Stokes disc diffusion method. The MIC of 60 randomly isolated strains of S. typhi was determined by agar dilution method using Mueller Hinton Agar medium.

RESULTS

Isolation rates of Salmonella spp. increased in 2000 and 2001. Multidrug resistance (MDR) in S. typhi had increased while in S. paratyphi it had decreased markedly. Ninety per cent chloramphenicol sensitivity was seen in S. typhi by MIC method. There was a decrease in the susceptibility to ciprofloxacin of S. typhi with MIC showing an upward trend. All S. typhi tested were sensitive to third generation cephalosporins and aminoglycosides with MIC well below the breakpoint.

DISCUSSION

Our study indicates that MDR in S. typhi is on the rise in our area. There is also re-emergence of chloramphenicol sensitivity. Rising MIC values of ciprofloxacin may lead to prolonged treatment, delayed recovery or pose treatment failure. Thus, sensitivity pattern of causative organism must be sought before instituting appropriate therapy to prevent further emergence of drug resistance.

Bacteraemia in children

OBJECTIVES

(i)To know the etiology of bacteraemia in children, (ii) To learn the antibiotic sensitivity pattern of the isolates.

METHOD

Over the period of thirteen months 4,368 blood samples (for blood culture) were collected from children in the age group of 0 day-14 years, suspected of having fever and sepsis. Blood samples were collected for blood culture from each case. Organisms were isolated and identified by conventional methods. Antibiotic susceptibility for each isolate was determined by using modified Stokes method.

RESULT

1,001 cases (22.9%) were culture positive. Incidence of bacteraemia in neonates was 521(33.94%). Gram negative organisms were the most predominant isolates (88.8%). Commonest was Klebsiella 471 (47.1%) followed by Salmonella sp. 162 (16.2%) and Pseudomonas 80 (8%) whereas in gram positive, Staphylococcus aureus 76 (7.6%) was the most common. Maximum sensitivity was seen by sulbactum/cefaperazone combination-969 (98.2%) by all isolates. Linezolid 97 (99.0%) was the most sensitive drug for gram positive isolates.

CONCLUSION

Gram negative multidrug resistant organisms were the main cause of septicemia in all the age groups. Therefore great caution is required in selection of antibiotic therapy.

Purification, cloning, and DNA sequence analysis of a chitinase from an overproducing mutant of Streptomyces peucetius defective in daunorubicin biosynthesis

Extracellular chitinases of Streptomyces peucetius and a chitinase overproducing mutant, SPVI, were purified to homogeneity by ion exchange and gel filtration chromatography. The purified enzyme has a molecular mass of 42 kDa on SDS-PAGE, and the N-terminal amino acid sequence of the protein from the wild type showed homology to catalytic domains (Domain IV) of several other Streptomyces chitinases such as S. lividans 66, S. coelicolor A3(2), S. plicatus, and S. thermoviolaceus OPC-520. Purified SPVI chitinase cross-reacted to anti-chitinase antibodies of wild-type S. peucetius chitinase. A genomic library of SPVI constructed in E. coli using lambda DASH II was probed with chiC of S. lividans 66 to screen for the chitinase gene. A 2.7 kb fragment containing the chitinase gene was subcloned from a lambda DASH II clone, and sequenced. The deduced protein had a molecular mass of 68 kDa, and showed domain organization similar to that of S. lividans 66 chiC. The N-terminal amino acid sequence of the purified S. peucetius chitinase matched with the N-terminus of the catalytic domain, indicating the proteolytic processing of 68 kDa chitinase precursor protein to 42 kDa mature chitinase containing the catalytic domain only. A putative chiR sequence of a two-component regulatory system was found upstream of the chiC sequence.

Purification, cloning, and DNA sequence analysis of a chitinase from an overproducing mutant of Streptomyces peucetius defective in daunorubicin biosynthesis

Extracellular chitinases of Streptomyces peucetius and a chitinase overproducing mutant, SPVI, were purified to homogeneity by ion exchange and gel filtration chromatography. The purified enzyme has a molecular mass of 42 kDa on SDS-PAGE, and the N-terminal amino acid sequence of the protein from the wild type showed homology to catalytic domains (Domain IV) of several other Streptomyces chitinases such as S. lividans 66, S. coelicolor A3(2), S. plicatus, and S. thermoviolaceus OPC-520. Purified SPVI chitinase cross-reacted to anti-chitinase antibodies of wild-type S. peucetius chitinase. A genomic library of SPVI constructed in E. coli using λ DASH II was probed with chiC of S. lividans 66 to screen for the chitinase gene. A 2.7 kb fragment containing the chitinase gene was subcloned from a λ DASH II clone, and sequenced. The deduced protein had a molecular mass of 68 kDa, and showed domain organization similar to that of S. lividans 66 chiC. The N-terminal amino acid sequence of the purified S. peucetius chitinase matched with the N-terminus of the catalytic domain, indicating the proteolytic processing of 68 kDa chitinase precursor protein to 42 kDa mature chitinase containing the catalytic domain only. A putative chiR sequence of a two-component regulatory system was found upstream of the chiC sequence.Key words: chitinase, chitinase purification, Streptomyces peucetius, daunorubicin, chiC.