Christie, Atkins, Munch-Peterson (CAMP) Negative Listeria monocytogenes Meningitis in Neonates: Report of Two Cases

Listeria monocytogenes, a gram-positive bacillus and an intracellular pathogen, is an uncommon cause of illness in the general population. During pregnancy, a perinatal infection can lead to serious complications such as abortion, stillbirth, neonatal sepsis, and meningitis. We present two cases of neonatal meningitis caused by Christie, Atkins, Munch-Peterson (CAMP)-negative Listeria monocytogenes. In the first case, a seven-day-old female term neonate delivered vaginally, presented with high-grade fever and refusal to feed. In view of the suspected late-onset sepsis, a septic workup, including cerebrospinal fluid analysis, was conducted. CSF culture reports obtained showed a growth consistent with Listeria monocytogenes, which was CAMP test negative and susceptible to the penicillin group of drugs, cotrimoxazole, erythromycin, and meropenem. The isolate was identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and confirmed by 16S rRNA sequencing. The blood culture was sterile. At 48 hours of admission, the neonate clinically deteriorated with fluctuation in oxygen saturation below 95% at room air. Thus, she was electively intubated and connected to the mechanical ventilator with appropriate settings. The antibiotics were upgraded to meropenem from the empirical antibiotic therapy. The neonate showed clinical improvement within the next 24 hours of initiating antibiotics according to culture susceptibility and was gradually weaned from the mechanical ventilator to continuous positive airway pressure (CPAP). After 24 hours, she was able to maintain normal saturation at room air. In the second case, an 11-day-old low birth weight neonate, small for gestational age, was presented to the NICU with complaints of loose stools, fever, and refusal to feed for the past two days. In view of the suspected sepsis, relevant investigations were carried out while initiating empirical antibiotics IV piperacillin-tazobactam and IV amikacin for the neonate. Meanwhile, there was a dip in oxygen saturation noted on room air for the neonate and he/she was mechanically ventilated. The CSF culture grew Listeria monocytogenes,which was identified using MALDI-TOF MS and confirmed by 16S rRNA sequencing. The isolate tested negative for the CAMP test and was susceptible to ampicillin, penicillin, cotrimoxazole, erythromycin, and meropenem. The blood culture was sterile. The antibiotics were upgraded to meropenem from the empirical antibiotic therapy, the patient's condition improved, and the baby was eventually discharged.

First Case of Nocardia wallacei From India: A Case Report and Literature Review

Nocardia is a type of bacteria that can cause infections in both immunocompromised and immunocompetent hosts. It is an obligate aerobe and is commonly found in the environment. Pulmonary nocardiosis may present as pneumonia, endobronchial inflammatory masses, lung abscess, and cavitary disease with contiguous extension, leading to effusion and empyema. We present a case of pulmonary nocardiosis in a 75-year-old male patient with type 2 diabetes mellitus. The patient presented with bilateral pneumonia and hypoxia with an oxygen saturation of 85%. Sputum samples were sent to the microbiology laboratory for testing. Acid-fast staining with 1% H2SO4 showed acid-fast branching filamentous rods, but Nocardia could not be isolated in culture. The sample was subjected to 16S rRNA gene sequencing, which identified the pathogen as Nocardia wallacei. The culture of the sputum did not grow any pathogenic organisms, and the blood culture was sterile. Unfortunately, the patient left the hospital against medical advice as he was advised for intubation. The patient could not survive and died the next day after leaving the hospital. N. wallacei can be fatal and cause disseminated infection in both immunosuppressed and immunocompetent patients. Only eight case reports of N. wallacei have been reported in the literature from various parts of the world. Our case is the first case report of N. wallacei from India.

GeneXpert Ultra in Urine Samples for Diagnosis of Extra-Pulmonary Tuberculosis

Extra-pulmonary tuberculosis (EPTB) continues to be difficult to diagnose. Novel biomarkers in biological specimens offer promise. Detection of Mycobacterium tuberculosis (Mtb) DNA in urine could prove useful in diagnosis of EPTB, possibly due to disseminated disease or micro-abscesses reported in kidneys. The current study was designed to detect Mtb DNA in stored urine samples from patients with EPTB. Diagnosis of EPTB was reached using Microbiological Reference Standards (MRS) on samples from the disease site using WHO Recommended Diagnostics (WRD), [smear microscopy, liquid culture (MGIT-960)] and GX (molecular WRD, mWRD) and Comprehensive reference standards [CRS, clinical presentation, microbiological reference standards, radiology, histopathology]. GX-Ultra was performed on urine samples stored in -80oC deep freezer, retrospectively. Of 70 patients, 51 (72.9%) were classified as confirmed TB, 11 (15.7%) unconfirmed TB, and 8 (11.4%) unlikely TB. GX-Ultra in urine samples demonstrated sensitivity of 52.9% and specificity of 57.9% against MRS, and higher sensitivity of 56.5% and specificity of 100% against CRS. The sensitivity and specificity of GX-Ultra in urine was 53.6% and 75% for pus sample subset and 52.2% and 53.3% for fluid sample subset. Urine being non-invasive and easy to collect, detection of Mtb DNA using mWRD in urine samples is promising for diagnosis of EPTB.

Malarial Antibodies and Endemicity: Does It Affect SARS-CoV-2 Severity and Outcomes?

Background India has a disproportionately lower rate of coronavirus disease 2019 (COVID-19) severe disease and lower death rates with respect to other parts of the world. It has been proposed that malaria-endemic countries such as India are relatively protected against severe COVID-19 disease and deaths. Methods This was a cross-sectional, analytical, observational study conducted from August 2020 to July 2021 at a tertiary care COVID-19-designated center in New Delhi, India. It aimed to study the association between antimalarial antibody levels and COVID-19 disease severity and outcomes. Results One hundred forty-six patients were included in the final analysis. The mean (standard deviation {SD}) age of the study population was 44.6 (17.2) years, and there were 85 (58.2%) males. Sixty-five patients had mild disease, 14 patients had moderate disease, and 67 patients had severe disease at the time of enrolment in the study. Forty-six patients expired during the hospital stay. For the antimalarial antibody, there was a statistically significant difference between mild and moderate (p=0.018), mild and severe (p=0.016), and mild and combined moderate and severe diseases (p=0.013). However, there was no difference between the patients who survived and those who did not. Conclusion Antimalarial antibody levels may not be associated with the outcomes of COVID-19 during hospital stay. However, this study has provided some insights into the relationship between the severity and outcomes of COVID-19 and the levels of antimalarial antibodies.

Seroprevalence of Strongyloides infection among steroid recipients in a tertiary care centre in North India

BACKGROUND

Strongyloides stercoralis (S. stercoralis), a unique parasite, can cause mortal disease even years after the exposure. Iatrogenic use of steroids can complicate asymptomatic infections to a life-threatening hyperinfection and/or disseminated infection. Data regarding seroprevalence of strongyloidiasis remains scarce and this knowledge gap needs due attention in many endemic countries including India.

AIM

The present study is aimed at assessing the seroprevalence of Strongyloides infection and the need for routine screening among individuals receiving steroid therapy.

METHODOLOGY

Eighty patients receiving steroid therapy and thirty healthy volunteers who had not received any immunosuppressive drugs and/or anthelminthic therapy in last six months were enrolled as cases and controls respectively and they were screened by Strongyloides IgG ELISA.

RESULTS

Among the 80 patients on steroids, the mean cumulative prednisolone equivalent dose received was 8.2 g (±11.2 g) for a mean duration of 184 days, 16 patients (20%, 95% CI 11.9-30) had a positive Strongyloides IgG serology. Only 4 controls (4/30, 13.3%, CI 3.8-30.7) tested positive (p=0.4).

CONCLUSIONS

Our study demonstrated a Strongyloides seroprevalence of 20% in the study population emphasizing the need for screening for Strongyloides infection prior to immunosuppressive therapy in order to prevent hyperinfection or possible dissemination.

Genomic analysis of Fosfomycin resistance in multi-drug resistant uropathogens and comparison of in-vitro susceptibility methods uropathogens

BACKGROUND AND OBJECTIVES

Urinary tract infection is one of the most common bacterial infections causing high morbidity and mortality. The alarming rise of multidrug-resistant uropathogens worldwide forced the clinician to rethink the old drugs like Fosfomycin for its therapeutic management. Our objective was to compare agar dilution, disc diffusion and E-test method for antimicrobial susceptibility testing of Fosfomycin against different drug-resistant uropathogens.

MATERIALS AND METHODS

Consecutive 181 uropathogens were tested for Fosfomycin susceptibility using agar dilution, disc diffusion and E-test. Results were interpreted using Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. Whole genome sequencing analysis was done on the 4 XDR/PDR Fosfomycin resistant Klebsiella pneumoniae isolates.

RESULTS

Escherichia coli was found as the most common (62.4%) uropathogen followed by Klebsiella pneumoniae (21%). Considering agar dilution as the gold standard, 6.1% of isolates were resistant to Fosfomycin. Following CLSI breakpoints, the susceptibility of Escherichia coli, Klebsiella pneumoniae, other Enterobacterales and Pseudomonas aeruginosa were 92.9%, 92.1%, 100%, 100%; whereas using EUCAST breakpoints the susceptibility rates were 85.7%, 86.9%, 92.9%, and 100%, respectively. The essential agreement, categorical agreement, major error, and very major error for E-test/disc diffusion for all the organisms were 91.2%/Not Applicable, 95%/93.9%, 1.8%/4.7%, 9.1%/9.1%, respectively. Whole-genome sequencing showed mutation UhpT gene as well as the presence of plasmid-mediated fosA5 or fosA6 genes conferring Fosfomycin resistance.

CONCLUSION

This result supports very low resistance of Enterobacterales against Fosfomycin; hence should be considered a valuable option to treat multidrug-resistant uropathogens. Disc diffusion was observed to be a convenient method for Fosfomycin susceptibility testing compared to agar dilution.

Analysis of colistin resistance in carbapenem-resistant Enterobacterales and XDR Klebsiella pneumoniae

Introduction:

Increasing occurrence of infections caused by multidrug-resistant Gram-negative bacteria resulted in colistin being the last agent for treatment. Apart from plasmid-mediated mcr genes, mutations involving several genes like mgrB, phoP/phoQ, pmrA, pmrB, pmrC, and crrABC genes, are leading causes of colistin resistance. Four colistin susceptibility testing methods were compared against broth microdilution (BMD) and determined the presence of the mcr1-5 gene.

Methodology:

A total of 100 carbapenem-resistant Enterobacterales isolates were tested for colistin susceptibility by commercial broth microdilution (cBMD), E-test, VITEK-2, and rapid polymyxin NP assay (RPNP) and compared with BMD. The presence of the mcr1-5 gene was determined by modified RPNP and PCR. Two non-mcr colistin-resistant XDR isolates were subjected to whole-genome sequencing using Illumina MiSeq sequencing platform.

Results:

Among 100 carbapenem-resistant Enterobacterales isolates, 15% were resistant to colistin. Essential agreement, categorical agreement, major error, and very major error for cBMD/E-test/VITEK-2/RPNP were 96%/73%/82%/NA; 99%/86%/88%/91%, 1.2%/9.4%/11.8%/8.2% and 0%/40%/13.3%/13.3%, respectively. Only one Klebsiella pneumoniae isolate harbored the mcr-1 gene, observed by both methods. Whole-genome sequencing of two non-mcr XDR Klebsiella pneumoniae showed multiple mutations in 10 genes responsible for lipopolysaccharide biosynthesis.

Conclusions:

The performance of cBMD was excellent, whereas the E-test was unacceptable. VITEK-2 and RPNP performed better but remained unreliable due to high error rates. Multiple mutations in the target proteins involving lipopolysaccharide formation, modification, and regulation were seen, resulting in colistin resistance.

Intestinal Colonization Due to Carbapenem-Resistant Enterobacteriaceae Among Hematological Malignancy Patients in India: Prevalence and Molecular Charecterisation

Faecal carriage of Carbapenem-resistant Enterobacteriaceae (CRE) is being observed as an important risk factor for bacteremia among patients with hematological malignancies. A prospective surveillance study was conducted among these patients to determine the gut colonization of CRE. Rectal/perianal swabs were collected to isolate CRE. Carbapenem resistance was detected by disk diffusion, modified-Hodge, Carba-NP test, and PCR for ^bla NDM-1, ^bla KPC, ^bla OXA-48, ^bla VIM, ^bla IMP genes. A total of 209 CRE isolates were identified from 151 patients. E. coli was the most common (83.2%) CRE identified, followed by Klebsiella spp. (9.6%). The majority of CRE were observed resistant to ertapenem (86%). ^bla NDM-1 was the most common gene (57.3%), followed by ^bla OXA-48 (37.8%). 26.8% isolates found to carry both ^bla NDM-1 and ^bla OXA-48 genes. CRE is increasingly observed to cause bacteremia among hematological malignancy patients due to increased colonization. Screening for gut CRE colonization is necessary to guide empirical therapy and apply infection control measures among these patients.

Use of Ertapenem as a Marker for Detection of Carbapenem Resistance for Enterobacteriaceae

Introduction: Detection of carbapenem resistance in the clinical microbiology laboratory is challenging. Production of carbapenemase enzymes remains the most important mechanism among Carbapenem Resistant Enterobacteriaceae (CRE). Ertapenem has been found as a sensitive marker for detecting CRE, especially the non-carbapenemase producing CRE. However, limited literature is available discussing its specificity and sensitivity in comparison to gold standard tests. Aim: To compare the ability of the ertapenem disc diffusion test with other confirmatory tests i.e., Epsilometer test (E test), Carbapenemase Nordmann-Poirel (CNP) test, and Polymerase Chain Reaction (PCR) for CRE identification. Materials and Methods: Seventy six phenotypically confirmed Enterobacteriaceae isolates were tested for carbapenem resistance. Ertapenem susceptibility was compared with imipenem, meropenem, and doripenem disc individually and in combination to determine its sensitivity. Further, it was compared with the E test, CNP test, and PCR to find the concordance of the result. Data were analysed by statistical software using Chi-square test with p-value <0.05 as significant. Results: Ertapenem disc independently was able to detect maximum resistant isolates (64/76) in comparison to other individual carbapenem discs or their combinations. Among the four carbapenem discs, the result of the ertapenem disc showed maximum concordance with its corresponding E test. The sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) of the Ertapenem disc compared to the gold standard tests (CNP and PCR) were 89.7%, 62.5%, 95.3%, and 41.7%, respectively. Conclusion: Disc diffusion test using ertapenem disc was observed as a sensitive marker for detecting CRE. The result of the ertapenem disc diffusion test was observed less discordant with E test, CNP test, and PCR in comparison to other carbapenem discs.

Emergence of Burkholderia cepacia in ICU Setting

BACKGROUND

B. cepacia is metabolically versatile organism which is not only resistant to many antibiotics but also disinfectants. This makes their survival easy even in restricted areas like intensive care unit (ICU) and management difficult.

AIMS AND OBJECTIVES

To describe sudden emergence of Burkholderia at a tertiary care centre ICU setting in milieu of colistin usage.

MATERIALS AND METHODS

Cases were patients with culture proven B.cepacia. They were picked up as non-lactose fermenting, oxidase positive, motile, gram-negative bacilli which was resistant to colistin and aminoglycosides and sensitive to cotrimoxazole. These isolates were further confirmed by both VITEK-2 compact system (Biomerieux, France) and standard bacterial techniques.Colistin consumption data were retrospectively collected from medical store records of hospitals and individual ICU pharmacy records from January 2016 to June 2016, and were expressed as total dialy doses in a month per 1000 patient days (DDD/1000PD).

RESULTS

An increase was observed in B. cepacia infection linked to increased consumption of colistin in ICU.

CONCLUSION

Based on these results an increase was observed in B.cepacia infection which correlated with increased consumption of colistin in ICU. We speculate that extensive use of colistin may lead to selection of intrinsically resistant B. cepacia and may facilitate their spread as nosocomial pathogens.

HOW TO CITE THIS ARTICLE

Meena S, Bir R, Sood S, Das BK, Kapil A. Emergence of Burkholderia cepacia in ICU Setting. Indian J Crit Care Med 2019;23(9):423-426.

Comparative evaluation of in-house Carba NP test with other phenotypic tests for rapid detection of carbapenem-resistant Enterobacteriaceae

BACKGROUND

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is alarming worldwide causing serious infections. Rapid and accurate identification of CRE is crucial to reduce the mortality and morbidity. In this study, we tried to develop an in-house Carba NP test for detection of CRE and evaluate its performance with others.

METHODS

A prospective study was conducted with 40 nonrepeating Enterobacteriaceae isolates over a period of 3 months. All the isolates were screened for carbapenem resistance as per CLSI 2016 guidelines followed by PCR for blaNDM-1, blaOXA-48, blaKPC, blaVIM, and blaIMP genes. All the isolates were subjected to five phenotypic tests, that is, in-house Carba NP (iCarba NP), commercial Carba NP (cCarba NP), Blue-Carba, modified Hodge test (MHT), and CHROMagar.

RESULTS

Among the 40 isolates, 87.5% were identified as Escherichia coli, 7.5% were Klebsiella pneumoniae, 2.5% were Enterobacter cloacae, and 2.5% were Citrobacter freundii. Thirty-three of 40 (82.5%) isolates were found to harbor one or more resistant genes. Considering PCR to be the gold standard test, sensitivity of the phenotypic methods for CRE detection ranged from 63.6% (MHT) to 96.9% (CHROMagar). Both cCarba NP and iCarba NP observed to have highest specificity. The performance of iCarba NP was found comparable with cCarba NP by kappa score 1 and found approximately 10 times less expensive than cCarba NP.

CONCLUSION

CHROMagar was observed most sensitive assay for detection of CRE followed by both Carba NP tests. iCarba NP was proved cheaper and equally good as cCarba NP for detection of CRE.

Detection of multidrug-resistant tuberculosis using MGIT™(TM) and MAS-PCR in Tripura, India

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) poses a global threat that is further compounded by the human immunodeficiency virus (HIV) epidemic.

OBJECTIVE

To detect MDR-TB among pulmonary TB (PTB) patients with or without HIV coinfection by isolating and identifying Mycobacterium tuberculosis from clinical samples and performing drug susceptibility testing (DST).

METHODS

Sputum was collected from presumed PTB cases. Microscopic examination was performed following Ziehl-Neelsen (ZN) staining and cultured in Löwenstein-Jensen (LJ) medium. First-line anti-tuberculosis DST of the isolates was performed using MGIT™ (Mycobacterial Growth Indicator Tube) and multiplex allele-specific polymerase chain reaction (MAS-PCR).

RESULTS

Of 172 study subjects, 59.3% (102/172) were smear-positive and 40.7% (70/172) were smear-negative. In the smear-positive and -negative groups, respectively 62.7% (64/102) and 8.6% (6/70) were culture-positive. DST on MGIT showed a cumulative resistance of 7.1% (5/70) to isoniazid (INH) and rifampicin. More ethambutol (EMB) and combined INH+EMB resistance was detected using MAS-PCR.

CONCLUSION

MDR-TB is a problem in Tripura, and culture and phenotypic DST are required for diagnosis. MAS-PCR may provide an alternative rapid screening tool.

Evaluation of Multidrug Resistant Staphylococcus aureus and their Association with Biofilm Production in a Tertiary Care Hospital, Tripura, Northeast India

BACKGROUND

High morbidity and mortality rates are associated with Methicillin-resistant Staphylococcus aureus (MRSA) because of development of multidrug resistance. Staphylococcus aureus (S. aureus) has the ability to colonize and form biofilms on biomaterials which is causing resistance towards antimicrobials and thus making them difficult to eradicate from the infected hosts.

MATERIALS AND METHODS

Culture isolation, identification was done following standard protocol and antibiogram of the isolates were done. The detection of MRSA, Macrolide-Lincosamide-Streptogramin B resistance (MLSB), vancomycin resistance phenotypes were done by using cefoxitin disc diffusion test, D zone test and vancomycin E test. Biofilm was detected by Congo red agar method.

RESULTS

A total of 100 (31.7%) S. aureus strains were isolated from 315 clinical specimens. The prevalence of MRSA was 47% (47/100) with 85.1% were homogeneous MRSA and 14.9% were heterogeneous. Out of 47 MRSA strains, 63.8% were Hospital acquired-MRSA (HA-MRSA) infections whereas rests 36.2% were caused by Community acquired-MRSA (CA-MRSA) strains. Maximum number of MRSA isolates belonged to group A biotype (34%). A 14.9% isolates were of nontypeable group. Out of 100 S. aureus isolates, the prevalence of Vancomycin resistant S. aureus (VRSA) was found to be 3%. The MLSB phenotypes showed that the rates of inducible MLSB (iMLSB), constitutive MLSB (cMLSB) and Macrolide-Streptogramin B (MSB) in case of MRSA to be 19.1%, 31.9% and 12.8%. Prevalence of low-level (MUP(L)) and high-level mupirocin resistance (MUP(H)) among MRSA was 19.1% and 6.4%. Biofilm production was found in 55% strains of S. aureus. Out of 47 MRSA strains 76.6%were producing biofilm in comparison to 38.8% in methicillin-sensitive S. aureus (MSSA). Higher degree of antibiotic resistance in biofilm producers was seen especially in case of ciprofloxacin, co-trimoxazole, rifampicin, kanamycin, erythromycin and clindamycin whereas gentamycin, tetracycline and penicillin resistance was more in non-biofilm producers.

CONCLUSION

This study shows high rate of circulating MRSA with a majority of these isolates are multi-drug resistant of which mostly are biofilm producers in our hospital setup. Development of antimicrobial stewardship program based on the local epidemiological data and national guidelines is the need of the hour.