Challenges in management of Candida auris meningitis secondary to infected ventriculoperitoneal shunt - A case report

Meningitis in patients with ventriculo-peritoneal shunt (VP shunt) caused by various species of Candida have been widely described in literature. However, reports describing Candida auris as a cause of meningitis is limited. In this case report we describe a case of multidrug resistant Candida auris meningitis secondary to VP shunt infection successfully treated with intrathecal amphotericin B deoxycholate and intravenous liposomal amphotericin B. This is the second case report of successful treatment of Candida auris meningitis from India. More literature regarding the use of intrathecal/intraventricular echinocandins including optimal dosing and duration of therapy is needed.

Atypical case presentations of Streptococcus pneumoniae from level 1 trauma centre in India -A case series

Streptococcus pneumoniae is a rare cause of appendicitis, skin soft tissue, and bloodstream infections. The clinical significance of its isolation from samples of skin or soft tissues and pus from the appendix is poorly understood. Invasive pneumococcal disease (IPD) continues to be a problem in India, associated with a high case fatality rate despite treatment facilities available in the hospital settings. In the present study, we report three adult cases, one presented as acute appendicitis, the other had skin and soft tissue infection, and third presented with bloodstream infection caused by Streptococcus pneumoniae from our level 1 trauma center. The patients with acute appendicitis and soft tissue infection recovered when treated with appropriate antimicrobial therapy, however, the one with pneumococcal sepsis could not be revived.

Comparison of Genotypic and Phenotypic Methods of Metallo-β- lactamase Detection in Acinetobacter spp

INTRODUCTION

MBL containing genes have been reported in all GNBs including Acinetobacter spp since 1990s which are worrisome as they are transmitted by mobile genetic elements. Thus, early detection of MBL encoding organisms is necessary. The current study was designed to identify the most sensitive cost-effective test which could be used as a screening test for detection of cabapenamase producing Acinetobacter isolates.

METHODOLOGY

All consecutive strains of Acinetobacter spp isolated from various clinical samples were included. All isolates found resistant to any of the carbapenems were tested for MBL production using MHT (on MacConkey Agar and Mueller Hinton Agar), Etest (using Imipenem/Meropenem-EDTA) and Combined Disc Test (using EDTA and 2 MPA as inhibitors and Ceftazidime/Imipenem/Meropenem as substrate discs). PCR was performed for representative strains for IMP, VIM, KPC, OXA and NDM-1 gene.

RESULTS

Total of 154 non-duplicate strains of Acinetobacter spp were isolated and identified, of which, 134 (88%) and 126 (82%) were resistant to meropenem and imipenem respectively. All 134 meropenem resistant strains were tested for MBL production and PCR was performed on 100 strains. 3(3%), 5(5%), 7(7%), 26(26%), and 51(51%) strains had IMP gene, VIM gene, KPC gene, OXA gene and NDM-1 gene. MHT on MAC had better performance than on MHA and dilution to 0.05 McFarland was not required.

CONCLUSION

MHT on MAC had best sensitivity when compared with gold standard PCR and was also cost effective. With ROC curve, we found that 2MPA was not a good MBL inhibitor when compared with EDTA..

Prevalence and characterization of beta-lactamase-producing Escherichia coli isolates from a tertiary care hospital in India

BACKGROUND:

The purpose of the study was to determine the prevalence and characterize the resistance profiles of Escherichia coli isolated from various clinical specimens by various phenotypic and genotypic methods.

MATERIALS AND METHODS:

A total of 196 consecutive, nonduplicate strains of clinically significant E. coli isolated from various clinical specimens were included in the study. Identification and antimicrobial susceptibility testing was performed by using Vitek-2 system (Biomerieux, France). Phenotypic detection of extended spectrum beta-lactamase (ESBLs), Amp-C-β lactamase (Amp C), and carbapenemase production was done by various combination of disc diffusion methods, minimum inhibitory concentration determination by E-test, followed by polymerase-chain-reaction for the detection of β-lactamase-encoding genes.

RESULTS:

Overall prevalence of ESBLs, Amp C, and carbapenemase production was found to be 88.3%, 42.2%, and 65.1% by the phenotypic detection methods. Our study also revealed high resistance rates against other antibiotics such as cefepime (89%), cefotaxime (95.4%), ceftazidime (85.4%), ceftriaxone (91.8%), cefpodoxime (92.7%), aztreonam (56.3%), piperacillin/tazobactam (89.2%), and ticarcillin/clavulanic acid (76.3%). The most prevalent ESBL gene was bla_TEM (67.30%), and least prevalent ESBL gene was bla_VEB (2.61%). In case of Amp C, bla_FOX gene (21.9%) was predominant. Among the genes encoding for carbapenemases, the most common gene was bla_NDM (61.7%) followed by bla_VIM (30.8%), bla_KPC (10.6%), bla_OXA-48 (5.3%), and bla_IMP (2.1%).

CONCLUSION:

Our findings suggest a high rate of ESBLs, Amp C, and carbapenemase production among the E. coli isolates. A combination of both phenotypic and genotypic methods would be ideal for better characterization of resistance patterns among the E. coli isolates.

Phenotypic & genotypic profile of antimicrobial resistance in Pseudomonas species in hospitalized patients

Background & objectives:

Nosocomial infections caused by multidrug-resistant, Pseudomonas species have become a major clinical and public health concern. The aim of this study was to characterize phenotypic and genotypic profile of antimicrobial resistance (AMR) in Pseudomonas spp. isolated from hospitalized patients.

Methods:

A total of 126 consecutive, non-duplicate isolates of Pseudomonas spp. isolated from various clinical samples were included in the study over a period of two years. Identification and antimicrobial sensitivity was performed using automated culture system according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. Phenotypic detection of extended-spectrum β-lactamases (ESBLs), Amp-C β-lactamase (AmpC) and metallo-β-lactamases (MBLs) were done by various combinations of disc-diffusion and E-test methods, followed by polymerase chain reaction-based detection of β-lactamase-encoding genes.

Results:

Among 126 clinical isolates, 121 (96.1%) isolates were identified as Pseudomonas aeruginosa. Most of the isolates were recovered from pus sample, 35 (27.8%) followed by urine, 25 (19.84%); endotracheal aspirate, 24 (19.04%); blood, 14 (11.11%) and sputum, four (3.17%). The highest rate of resistance was against ticarcillin-clavulanic acid, 113 (89.7%) followed by meropenem, 92 (72.5%) and ceftazidime, 91 (72.3%). Overall, ESBLs, AmpC and carbapenemase production was detected in 109 (96.4%), 64 (50.8%) and 105 (94.6%) isolates by phenotypic methods. The most prevalent ESBL gene was bla_TEM in 72 (57.1%) and the least prevalent was bla_SHV in 19 (15.1%) isolates. AmpC gene was seen less compared to ESBL gene. The most prevalent carbapenemases gene was bla_NDM-1 41 (46.06%) followed by bla_VIM and bla_OXA-1.

Interpretation & conclusions:

Our findings suggested that a high rate of ESBLs and carbapenemases production was observed in Pseudomonas spp. Therefore, phenotypic and genotypic detection of AMR needs to be combined for better characterization of resistance patterns in Pseudomonas spp.

Prevalence and Characterization of Carbapenemase-producing Escherichia coli from a Tertiary Care Hospital in India

The purpose of this study was to estimate the prevalence and to characterize the carbapenemase-producing Escherichia coli by various phenotypic antimicrobial susceptibility testing methods, and its performance was compared to the gold standard genotypic method. The prevalence of carbapenemase-resistant E. coli was found to be 65%. The phenotypic methods evaluated are cost-effective and can be used in resource-limited laboratories to rule out carbapenem resistance.

Multidrug-Resistant Candida auris Fungemia in Critical Care Units: Experience from a Tertiary Care Hospital in India

Candida auris, a recently identified multiresistant Candida species, was first reported in Japan in 2009. It is different from other pathogenic yeast species because of its propensity to cause outbreaks and transmits between patients within health care settings. The invasive infections caused by C. auris are associated with high mortality rates, approaching 70% particularly in intensive care unit patients. Conventional biochemical methods are inaccurate in identifying this species of Candida. Although C. auris is frequently reported as multi-, extended-, or pan drug resistant to antifungal drugs, there is a wide variability in the susceptibility among reports worldwide. In this study we report a case series of five hospitalized patients with multidrug-resistant candidemia caused by C. auris in a tertiary hospital in India. Our finding suggests that correct identification followed by therapeutic intervention is necessary for favorable outcome in patients with C. auris fungemia.

Prevalence and antibiotic resistance profile of cerebrospinal fluid pathogens from neurosurgical patients from level 1 trauma center in India

Introduction:

The purpose of this study was to investigate the prevalence of Postoperative central nervous system infections (PCNSIs) and antibiotic resistance profiles of causative organisms in trauma patients following neuroinvasive procedures.

Materials and Methods:

This was a retrospective study conducted over a period of 4 years (2013–2017). All in-patients admitted under a neurotrauma unit meeting the inclusion criteria of PCNSIs were included in the study. Surgical site infections (SSIs) were defined according to the Centers for Disease Control and Prevention 2018 (CDC) criteria. We retrospectively examined the demographic characteristics, type of neurosurgery performed, laboratory data, causative organisms, and antimicrobial susceptibility testing results of patients who had positive cerebrospinal fluid cultures following craniotomy between January 2013 and December 2017.

Results:

Of total 2500 patients operated during the study, 961 patients were screened for PCNSIs. The estimated prevalence (95% confidence interval) of PCNSIs which is a type of organ/space SSI was 7.2% (6.3–8.3). Males were predominantly affected (85.0%). The mean age (standard deviation) of patients was 31.9 (16.5) years. Of all the cultures sent for microbiological examination, 18.6% were positive. The proportion of Gram-negative bacteria causing PCNSIs was 91.6%. Multidrug-resistant (MDR) Acinetobacter baumannii (41%) was the most common organism isolated. Among Gram-positive bacteria, the most common organism was Staphylococcus aureus (5.5%). All the Gram-positive isolates were susceptible to vancomycin, teicoplanin, and linezolid.

Conclusion:

There is a high burden of PCNSI caused by MDR Acinetobacter baumannii can pose a major clinical challenge with only few antimicrobials left in the pipeline.

Antibiotic resistance profile and co-production of extended spectrum beta lactamases and AmpC in Acinetobacter spp. in a level 1 trauma center from India

INTRODUCTION:

Acinetobacter baumannii has now emerged as a significant nosocomial pathogen in health-care setting ESP in intensive care units. Rapidly growing resistance among clinical isolates suggests a need to detect resistance mechanisms in this organism. The present study was designed to compare the various phenotypic tests available with the gold standard of genotype.

METHODOLOGY:

The present study was conducted to include all isolates of Acinetobacter spp. isolated over 3 years. Their resistance to various antibiotics was determined and extended spectrum beta-lactamases (ESBL) and AmpC production in the isolates showing resistance to ceftazidime/ceftriaxone/cefotaxime (CAZ/CTR/CTX) was determined. ESBL and AmpC production was confirmed using polymerase chain reaction (PCR).

RESULTS:

A total of 154 strains were isolated, and all the strains were tested for ESBL and AmpC detection. Of the strains tested, 15 (9.7%), 17 (11%), 24 (15.6%), 27 (17.5%), 54 (35%), 67 (43.5%), and 72 (46.7%) strains showed ESBL production using CTX/CTX-clavulanate double-disc synergy test (DDST), CTX/CTX-clavulanate E-test, CAZ/CAZ-clavulanate DDST, CAZ/CAZ-clavulanate E-test, Piperacillin/Piperacillin-tazobactam (TZ) DDST, CTR/CTR-Sulbactum DDST, and Piperacillin/Piperacillin-TZ E-test, respectively. 20 (12.9%) and 19 (12.3%) of strains were positive for AmpC production using AmpC disc test and Boronic acid inhibition test, respectively. Genotype analysis using PCR for TEM, SHV, CTXM, PER, and VEB genes was done and 69 (51.5%) strains were positive for TEM gene.

DISCUSSION:

ESBL detection in Acinetobacter spp. is difficult as standard guidelines for the same are not available unlike in enterobacteriaceae, and there are no zone diameter breakpoints for aztreonam and cefpodoxime. In comparison, piperacillin/piperacillin-TZ E-test had the best sensitivity and specificity for ESBL detection.

CONCLUSION:

Standard guidelines for ESBL detection in nil fermeners like Acinetobacter spp. must be laid down for ease of detection. Use of piperacillin/piperacillin-tazobactam E-test could be used as one of the standard methods.

Clostridium sordelli as a cause of gas gangrene in a trauma patient

Gas gangrene is a necrotic infection of the skin and soft tissue that is associated with high mortality and often necessitating amputation to control the infection. Clostridial myonecrosis is most often cause of gas gangrene and usually present in settings of trauma, surgery, malignancy, and other underlying immunocompromised conditions. The most common causative organism of clostridial myonecrosis is Clostridium perfringens followed by Clostridium septicum. Here, we are reporting an unusual case report of posttraumatic gas gangrene caused by Clostridium sordelli.

Linezolid-resistant Enterococcus faecalis in leukemia patients: Rare cases with review of literature

Resistance to linezolid is rare in clinical isolates of Enterococcus faecalis. Here, we report cases of linezolid resistant Enterococcus fecalis in leukemia patients with review of literature.

Multidrug resistant Elizabethkingia meningoseptica bacteremia - Experience from a level 1 trauma centre in India

Elizabethkingia meningoseptica (E. meningoseptica) is a non-fermenting gram negative organism that is commonly detected in the soil and water but is rarely reported to cause human infection. However it is emerging as a nosocomial pathogen in patients admitted in intensive care units (ICUs). Infections caused by this organism have a high mortality rate due to lack of effective therapeutic regimens and its intrinsic resistance to multiple antibiotics. We report our experience in managing Elizabethkingia meningoseptica (E. meningoseptica) septicemia in our ICU patients with septic shock during prolonged intensive care management. Over a two year period four cases were admitted into the polytrauma ICU developed sepsis due to E. meningoseptica. All these patients were on mechanical ventilation, had central venous catheter (CVC) and were exposed to various broad spectrum antibiotics. Of the four patients, three died and one recovered. E. meningoseptica infection should be considered as a possible etiological agent of sepsis in patients who do not respond to empirical therapy, as this results in an inappropriate choice of antimicrobial therapy, leading to increased morbidity and mortality of patients. Its unusual resistance pattern along with inherent resistance to colistin makes this organism difficult to treat unless susceptibility patterns are available.

Pyrosequencing: a rapid and effective sequencing method to diagnose drug-resistant tuberculosis

PURPOSE

This study was undertaken to evaluate the efficiency of the pyrosequencing (PSQ) assay for the rapid detection of resistance to rifampicin (RIF), fluoroquinolones (FQs) and second-line injectables (SLIs) such as capreomycin (CAP) and kanamycin (KAN) in Mycobacterium tuberculosis (Mtb) clinical isolates.

METHODOLOGY

Pyrosequencing is a simple and accurate short read DNA sequencing method for genome analysis. DNA extraction from Mtb clinical isolates was performed using Tris-HCl buffer and chloroform. The rpoB (RIF), gyrA (FQs) and rrs (aminoglycosides) genes were amplified, followed by sequencing using the PyroMark Q24 ID system. The PSQ results were compared with the results from the conventional drug susceptibility testing performed in the laboratory.

RESULTS

The sensitivity of the PSQ assay for the detection of resistance to RIF, FQ, CAP and KAN was 100 %, 100 %, 40 % and 50 %, respectively. The specificity of the PSQ assay was 100 %.

CONCLUSION

The PSQ assay is a rapid and effective method for detecting drug resistance mutations from Mtb clinical isolates in a short period of time.