Bipasa Chakraborty

Prevalence of Pseudomonas aeruginosa and Acinetobacter spp producing metallo-β-lactamase in a tertiary care hospital

Background: Hospital acquired infection (HAI) due to multidrug resistant pathogens are increasing day by day. Among which MBL producing Pseudomonas aeruginosa and Acinetobacter spp contribute a major portion of HAI. Aims: The objective is to determine the antibiotic susceptibility pattern of P. aeruginosa and Acinetobacter spp. showing imipenem resistance and prevalence of MBL producing strains among them in a tertiary care hospital. Materials and Methods: Over a period of 5 months in a tertiary care hospital, 60 Pseudomonas aeruginosa and 50 Acinetobacter spp. were isolated. These were tested phenotypically for detection of metallo-β-lactamase (MBL) production, by imipenem-ethylenediaminetetraacetic acid (EDTA) combined disc method and by four fold or more reduction of minimum inhibitory concentration (MIC) against imipenem with EDTA. Result and Conclusion: The prevalence of MBL producing Pseudomonas aeruginosa was found to be 41% and Acinetobacter spp. 22%. Antibiotic susceptibility tests revealed multidrug resistance for most antibiotics but 100% sensitivity for colistin. A big proportion of these positive strains were isolated from patients with multiple risk factors like prolonged hospital stay, indwelling urinary catheter, continuous mechanical ventilation, prolonged antimicrobial therapy, intravenous lines. The overall mortality rate among them was as high as 21%.

Ventilator associated pneumonia in a tertiary care hospital in India: Incidence, etiology, risk factors, role of multidrug resistant pathogens

Background: Ventilator associated pneumonia (VAP), a hospital acquired infection (HAI) is seen among critically ill patients on mechanical ventilation (MV) due to various causes, in intensive care units (ICUs). VAP increases morbidity, mortality, as well as the cost of healthcare. Materials and Methods: A prospective study was done over a period of 10 months in a tertiary care hospital in India to determine the incidence, etiological agents, their sensitivity profiles, and risk factors associated with VAP. Combination disc method, ethylenediaminetetraacetic acid (EDTA) disc synergy (EDS) tests, and AmpC disc tests were performed for detection of extended-spectrum beta-lactamases (ESBL), metallo-beta-lactamases (MBL), and AmpC beta-lactamases, respectively. Results: One hundred and forty adult patients, on MV for 48 h and more, were included and 28 (20%) developed VAP. The incidence density rate of VAP was 21.875 per 1,000 ventilator days. Most of the patients had late onset VAP (60.7%) with average number of days for onset around 8 days. Pseudomonas spp. and Acinetobacter spp. were significantly associated with late onset VAP, whereas Enterobacteriaceae, Staphylococcus aureus , Haemophilus influenzae , Streptococcus pneumoniae , Burkholderia cepacia, and Candida species were commonly isolated from early onset VAP. Polymicrobial infections occurred in 14 cases, so overall 43 VAP pathogens were isolated. Thirty (69.7%) of them were multidrug resistant (MDR), among which ESBL contributed 23.25%, MBL 30.23%, AmpC beta-lactamases 9.30%, and to methicillin resistant S. aureus (MRSA) contributed 6.97%. Prior antibiotic therapy ( P P P P P = 0.0012), and impaired consciousness ( P = 0.0191) were significant risk factors for VAP. Conclusions: Proper knowledge of risk factors can help identify high risk groups for VAP, among the critically ill patients on MV. MDR pathogens, with production of ESBL, MBL, AmpC beta-lactamases, and MRSA were commonly associated with VAP. So, judicious use of antibiotic is recommended.

Comparative evaluation of loop-mediated isothermal amplification and conventional methods to diagnose extrapulmonary tuberculosis

Background: Extra-pulmonary tuberculosis is difficult to diagnose by conventional methods, because they are less sensitive and more time consuming. Loop-mediated Isothermal Amplification (LAMP) is a novel gene amplification method that has been developed to diagnose Mycobacterium tuberculosis complex in pulmonary and paucibacillary extrapulmonary specimens even in resource poor settings. Aims and Objectives: To evaluate the sensitivity and specificity of LAMP to detect Mycobacterium tuberculosis complex in paucibacillary extra-pulmonary specimens and to compare the results with other conventional methods in extrapulmonary specimens. Materials and Methods: 45 specimens from suspected extrapulmonary tuberculosis patients were collected and tested by LAMP method after DNA extraction. Simultaneously, these specimens were tested by smear microscopy, solid and liquid culture methods. Culture positivity, either in solid or liquid culture, was considered as a confirmed case of extrapulmonary tuberculosis. Results: Sensitivity of LAMP was 95.6% whereas for liquid culture, solid culture and smear microscopy were 69.6%, 65.2% and 17.4% respectively. Specificity for LAMP was 95.4% and for other 3 conventional methods were 100%. Positive predictive values, negative predictive values and likelihood ratios were also evaluated. Turn-around time (TAT) for LAMP was 8 hours only whereas for liquid culture was 2-4 weeks, and for solid culture it was 4-8 weeks. Conclusion: LAMP was a simple, rapid and cost-effective procedure with good sensitivity and specificity. It was found to be better than conventional methods to diagnose extrapulmonary tuberculosis.

Does the Benefit of Salvage Amputation Always Outweigh Disability in Drug­ Failure Mycetoma?: A Tale of Two Cases

It is popularly believed that eumycetoma cases should be dealt with using surgical amputation for a better chance of cure especially when chemotherapy has failed. However, amputation leads to disability on one hand and on the other it may also fail to be curative. We present two cases with contrasting treatment options and outcome. In the eumycetoma case reported here, a 40-year-old male presented with right foot swelling for 16 years, from which Scedosporium apiospermum was isolated. He responded poorly to antifungal therapy and refused below-knee amputation 12 years ago. With counseling and wound care his condition improved, and Foot and Ankle Ability Measure (FAAM) score remained almost stable at 90% for 16 years, which is much better than the average functional outcome after amputation. Another 46-year-old female underwent below-knee amputation after receiving incomplete courses of antibiotics and antifungals for mycetoma of unknown etiology. She presented to us after recurrence of mycetoma on an amputated stump and was successfully treated by proper courses of antibiotics after detecting the causal agent, Actinomadura madurae. Her post-amputation disability and depression could have been avoided if the hasty decision of amputation had not been taken. In our opinion, living with drug-non-responsive mycetoma, supported by symptomatic management, may be a better option than amputation and its associated morbidities. So before taking the path of salvage amputation, we must consider many aspects, including patients livelihood, psychological aspects and chances of recurrence even after the procedure.

A case report of nonhealing leg ulcer infected with Stenotrophomonas maltophilia in an immunocompetent patient in a Tertiary Care Hospital of Eastern India

Stenotrophomonas maltophilia is an aerobic, motile Gram-negative, nonfermentative bacillus considered as an opportunistic pathogen causing infection typically in individuals with immunosuppression, organ transplantation and malignancies. Contaminated water or medical devices in the hospital environment are the primary causes of infection. Here, we report a case of nonhealing leg ulcer infected with S. maltophilia in an immunocompetent individual.

An unusual case of chronic nonhealing periorbital ulceration due to a new species of Corynebacterium sp. strain UCL557

Nondiphtherial Corynebacterium (diphtheroids) has been related to blood and wound infections but are an uncommon cause for soft tissue infection. We report a case of periorbital soft tissue infection with ulceration caused by multidrug-resistant Corynebacterium spp. in a 9-year-old girl who is apparently immunocompetant. Computed tomography scan showed soft tissue involvement of right periorbital region with no bony destructions or focal calcifications. Vision remained unaffected. Patient was treated by debridement and skin grafting, but condition did not improve. Pus collected from the periorbital ulcerated area was cultured in blood agar and Corynebacterium spp. was isolated from the pure culture, which was identified as a new species Corynebacterium sp. strain UCL557 using 16S rDNA- based molecular technique based on nucleotide homology and phylogenetic analysis. Antibiogram showed multiresistance pattern with sensitivity to ceftriaxone-sulbactum vancomycin and linezolid. After initiation of treatment with vancomycin infusion and oral linezolid, the patient responded well and lesion started to heal. To the best of our knowledge, this is the first ever case report of periorbital ulceration by new species of Corynebacterium sp. strain UCL557.

Rethink on recommended concentrations of disinfectants in the light of biofilm, based on in vitro study

Background: Some medical devices are reused after treatment with disinfectants at manufacturer′s recommended concentrations (RCs), based on experimental evaluation studies of their bactericidal, sporicidal, and mycobactericidal concentrations. However, this may not be sufficient to eliminate all colonized highly drug-resistant biofilms on medical devices, resulting possibility in iatrogenic infections by recolonization of highly resistant persisters. The objective of this study is to evaluate the antibacterial efficacy of different concentrations of novel and conventional disinfectants on in vitro grown biofilm of multidrug-resistant nosocomial bacterial isolates and a reference strain. Materials and Methods: Multidrug-resistant and strong biofilm producers Pseudomonas aeruginosa (n = 4) and Escherichia coli (n = 5) nosocomial isolates and one reference strain, P. aeruginosa PAO-1, were selected after testing their biofilm status by modified Christensen′s method and Stepanovic′s interpretative criteria. The activity of three different groups of new disinfectants, Novacide, Virkon, Silvicide and two conventional disinfectants, phenol and glutaraldehyde, were assessed on their in vitro grown biofilms as percentage of total surviving bacteria within biofilm matrix after challenge at different concentrations in terms of multiples of RC and different contact time. Results: Modified RCs for Virkon, phenol, and Silvicide, as pointed out by in vitro study, were 4, 8, and 10 times higher than the one suggested by the manufacturer. Novacide was least effective, whereas glutaraldehyde at its available concentration was also not effective in removal of biofilm bioburden. Conclusions: RC was not sufficient to eliminate the in vitro biofilms tested in this study. Further studies using medical devices materials should be performed for clarification. However, this study points out possible relevant limitations of currently used hospital disinfectants and concentrations against biofilms. Additional measures to prevent reinfections related to their use of medical devices are mandatory, and this study suggests that optimization of disinfectants concentrations may be highly relevant.

HIV in Intensive Care Unit: Concerns and Constraints of Intensivists

The increasing prevalence of HIV (human immunodeficiency virus) infection in recent times has led to increasing exposure, and the possibility of nosocomial transmission of HIV. The present day scenario highlights the need for intensivists to enforce strict adherence to infection control protocol at site when working in ICU. Thus strict adherence to Standard precautions when handling body fluids especially hand washing, proper management of accidental needle-stick injury and scientific disposal of biomedical waste along with current PEP guidelines are of paramount importance. In the HAART era, though hospitalisation of HIV infected patients has significantly decreased, but the rate of ICU admissions is still high. HIV patients may be admitted to ICU for many reasons, of which acute respiratory failure as a result of opportunistic infections accounts for approximately 25-50%. Today, HIV patients are being admitted to the ICU for medical and surgical causes unrelated to their HIV infection, such as malignancies, pacemaker implant, liver and renal diseases, minimal invasive surgeries like laparoscopic ones, orthopaedic surgeries for fractures and implants, brain surgery for road traffic accident injury are only a few. The number of persons living with HIV/AIDS (PLWHA) has increased and critical care specialists may be more likely to admit more HIV patients to the ICU and pursue aggressive life-support measures. But for resource constrained countries, where population and ICU bed ratio are abysmally low, decisions for admission in ICU by critical care specialists are often made in the absence of explicit policies and guidelines. Global and national commitments are required, providing proper HIV treatment and prophylaxis without discrimination and maintaining accountability and code of ethics.

A case report of white grain eumycetoma caused by Scedosporium apiospermum in a tertiary care hospital of the Eastern India

Scedosporium apiospermum and its asexual state Pseudallecheria boydiiare increasingly recognized as an opportunistic pathogen. Here, we describe a white grain eumycetoma of left foot of a 48-year-old female caused by S. apiospermum. Treatment with oral voriconazole was successful.