Exploring the Prevalence, Predictors, and Impact of Bacterial Infections to Guide Empiric Antimicrobial Decisions in Cirrhosis (EPIC-AD)

Background/Aims

This study delved into cirrhosis-related infections to unveil their epidemiology, risk factors, and implications for antimicrobial decisions.

Methods

We analyzed acutely decompensated cirrhosis patients (n = 971) from North India between 2013-2023 at a tertiary center. Microbiological and clinical features based on infection sites (EASL criteria) and patient outcomes were assessed.

Results

Median age was 45 years; 87% were males with 47% having alcoholic hepatitis. Of these, 675 (69.5%) had infections; 305 (45%) were culture-confirmed. Notably, 71% of confirmed cases were multi-drug resistant organisms (MDRO)-related, chiefly carbapenem-resistant (48%). MDRO prevalence was highest in pulmonary (80.5%) and skin-soft-tissue infections (76.5%). Site-specific distribution and antimicrobials were suggested. Predictive models identified prior hospitalization [OR:2.23 (CI:1.58-3.14)], norfloxacin prophylaxis [OR:2.26 (CI:1.44-3.55)], prior broad-spectrum antibiotic exposure [OR:1.61 (CI:1.12-2.30)], presence of systemic inflammatory response-SIRS [OR:1.75 (CI: 1.23-2.47)], procalcitonin [OR:4.64 (CI:3.36-6.40)], and HE grade [OR:1.41 (CI:1.04-1.90)], with an area under curve; AUC of 0.891 for infection prediction. For MDRO infection prediction, second infection [OR: 7.19 (CI: 4.11-12.56)], norfloxacin prophylaxis [OR: 2.76 (CI: 1.84-4.13)], CLIF-C OF [OR: 1.10 (CI: 1.01-1.20)], prior broad-spectrum antibiotic exposure [OR: 1.66 (CI: 1.07-2.55)], rifaximin [OR: 040 (0.22-0.74)] multisite [OR: 3.67 (CI: 1.07-12.56)], and polymicrobial infection [OR: 4.55 (CI: 1.45-14.17)] yielded an AUC of 0.779 and 93% specificity. Norfloxacin prophylaxis, multisite infection, mechanical ventilation, prior broad-spectrum antibiotic exposure, and infection as acute precipitant predicted carbapenem-resistant infection (AUC: 0.821). Infections (culture-proven or probable), MDROs, carbapenem/pan-drug resistance, and second infections independently linked with mortality (P < 0.001), adjusted for age, leucocytosis, and organ failures. A model incorporating age [HR:1.02 (CI: 1.01-1.03), infection [HR:1.52 (CI: 1.05-2.20)], prior hospitalization [HR:5.33 (CI: 3.75-7.57)], norfloxacin [HR:1.29 (CI: 1.01-1.65)], multisite infection [HR:1.47 (CI:1.06-2.04)], and chronic liver failure consortium-organ failure score; CLIF-C OF [HR:1.17 (CI: 1.11-1.23)] predicted mortality with C-statistics of 0.782 (P < 0.05).

Conclusion

High MDRO burden, especially carbapenem-resistant, necessitates urgent control measures in cirrhosis. Site-specific epidemiology and risk models can guide empirical antimicrobial choices in cirrhosis management.

Novel diagnostic approach for amoebic liver abscess using cell free (cf) DNA: a prospective study

BACKGROUND

Amoebic liver abscess (ALA) is commonly seen in tropical countries and diagnosis of ALA relies mainly on non-specific serological and imaging techniques as well as PCR from pus.

OBJECTIVE

This study evaluated the potential of using cell free DNA (cfDNA) from serum and urine for diagnosing ALA.

METHODS

We prospectively evaluated quantitative PCR (qPCR) for detection of cf DNA in serum and urine sample in all liver abscess patients. The samples were collected from patients reporting to emergency ward of Postgraduate Institute of Medical Education and Research, Chandigarh, India with symptoms suggestive of liver abscess. Real time PCR was done to detect cf DNA in serum and urine by targeting 99-bp unit of small subunit rRNA of Entamoeba histolytica and conventional PCR for pus.

RESULTS

A total 113 samples (serum and urine) and 100 pus samples were analysed. A total of 62 ALA patients were confirmed; with maximum 57 patients detected by qPCR for cfDNA in the serum, 55 patients by PCR on pus aspirate and 50 ALA patients by qPCR for cfDNA in urine sample. Therefore, the sensitivity of qPCR for detection of cf DNA in serum was 91.94% and for urine was 80.65%.

CONCLUSION

A total of 11.2% of ALA patients were diagnosed only through detection of E. histolytica cf DNA in their serum and urine. Detection of cfDNA from serum, urine of ALA has a potential role in future especially for developing countries as it is a rapid, sensitive and patient friendly diagnostic approach.

Changing spectrum of primary pyomyositis in North India

Recent data have demonstrated the changing epidemiology of primary pyomyositis worldwide. Our hospital-based retrospective study investigated the clinical and microbiological spectrum of primary pyomyositis between 2013 and 2021 in PGIMER (Chandigarh), India. Over a quarter had predisposing conditions, mainly diabetes mellitus and immunosuppressive therapy. Fever, muscle pain, local swelling and breathlessness were the usual presentations, with quadriceps, iliopsoas and gluteal muscles commonly affected. Staphylococcus aureus was the predominant cause, with c.50% methicillin-resistant strains. Almost two-thirds presented with metastatic infection (stage 3 pyomyositis), frequently with septic lung emboli. Patients with methicillin-sensitive and resistant Staphylococcus aureus had a similar incidence of metastatic infection. In-hospital mortality was c.10% and was strongly associated with a high international normalised ratio. Primary pyomyositis remains a significant problem, with a dramatic increase in community-associated methicillin-resistant Staphylococcus aureus.

Salmonella enterica serovar Give causing brain abscess and bacteremia: A case report

Non-typhoidal Salmonellosis are an important cause of gastroenteritis and invasive disease in developing countries, with increase resistance and mortality in paediatric age group. We report here, a rare case of bacteremia and brain abscess in a 3year old female child with Salmonella enterica serovar Give as a causative organism.

Cycle threshold values of SARS-CoV-2 RNA in conjunctival swabs and nasopharyngeal secretions: a comparative study from a tertiary care center in India

PURPOSE

To detect the viral RNA load of SARS-CoV-2 in conjunctival swabs of COVID-19 patients, and compare with nasopharyngeal swabs.

METHODS

Conjunctival swabs of COVID-19 patients (with PCR positive nasopharyngeal swabs) were subjected to quantitative reverse transcription-polymerase chain reaction (RT-PCR) for detection of SARS-CoV-2 RNA. The cycle threshold (Ct) values of Open Reading Frame 1 (ORF 1 Ab gene) and nucleoprotein (N gene) PCRs were used to assess the viral RNA load, and compare them with the baseline values of nasopharyngeal swabs.

RESULTS

Of 93 patients, 17 (18.27%) demonstrated SARS-CoV-2 RNA in conjunctival swabs. Baseline nasopharyngeal swabs were collected at a median of 2 days; while, the conjunctival swabs were collected at median 7 days, from onset of illness (p < 0.001). Despite a significant delay in conjunctival swab collection than nasopharyngeal swabs, the Ct values (ORF or N gene PCRs) were comparable between nasopharyngeal swab and conjunctival swab samples. Subsequently, during the recovery period, in four of these 17 patients (with conjunctival swab positivity), when the second nasopharyngeal swab was 'negative', the conjunctival swab was 'positive'.

CONCLUSION

The conjunctival swabs demonstrated SARS-CoV-2 RNA in 17 (18.27%) of 93 COVID-19 patients. Our results may suggest a delayed or a prolonged shedding of the virus/viral RNA on the ocular surface than in nasopharyngeal mucosa.

Otogenic Cerebellar Abscess with Polymicrobial Anaerobic Infection in a Young Female- A Rare Presentation

Brain abscess is a serious clinical condition caused by a localized collection of pus within the brain tissue. This typically occurs as a result of an infection that originates from a nearby area, such as an ear, sinus, or dental infection, or an infection in the bloodstream. Streptococcus and Staphylococcus species are the most common organisms implicated in brain abscesses. Apart from aerobic growth, cases of mixed infections of both aerobic and anaerobic organisms are also commonly reported in the literature. Herein we report a 23-year-old immunocompetent female with chronic otitis media who presented with cerebellar abscess where the aerobic growth was sterile and anaerobic culture revealed pure growth of dual anaerobes viz… Peptostreptococcus and Bacteroides thetaiotaomicron. This case highlights the importance of prompt diagnosis and management of polymicrobial anaerobic infection in cases of brain abscess.

Diagnostic utility of procalcitonin for bacterial infections in diabetic ketoacidosis

Procalcitonin is a widely used infection biomarker; however, its utility in identifying bacterial infection in diabetic ketoacidosis (DKA) is unclear. We aimed to evaluate its diagnostic performance for detecting DKA cases triggered by bacterial infections. We reviewed 303 case records of patients aged ≥ 13 years with DKA admitted to the emergency department, PGIMER (Chandigarh), between 2017 and 2022. Baseline procalcitonin was measured by electrochemiluminescence immunoassay, and a value > 0.5 ng/mL was considered elevated. Both microbiological reference standard (MRS) and composite reference standard (CRS) were used to evaluate the diagnostic performance of procalcitonin. 151/303 (49.8%) DKA cases had infection precipitations. Bacterial infections were present in 98 patients (53 microbiologically confirmed), of which urinary tract infection (n = 42), pneumonia (n = 19), skin and soft-tissue infection (n = 13), and bacteremia (n = 11) were common. The median value of procalcitonin was higher with bacterial infections than in patients without (3.68 vs. 1.00, P-value < 0.001). An elevated procalcitonin to detect bacterial infections in DKA had sensitivity 84.69%, specificity 34.15%, positive likelihood ratio (LR +) 1.29, and negative likelihood ratio (LR -) 2.44, against CRS. Against MRS, both LR + and LR - further decreased to 1.23 and 1.81, respectively. Using the receiver-operating-characteristic curve, an optimal cut-off of procalcitonin was calculated at 1.775 ng/ml against both CRS (area under curve 0.655, sensitivity 68.37%, specificity 59.02%, LR + 1.67, LR - 1.86, Yoden's index 0.274) and MRS (area under curve 0.616, sensitivity 67.92%, specificity 59.02%, LR + 1.66, LR - 1.84, Yoden's index 0.269). Procalcitonin does not help detect bacterial infections in patients with DKA at admission.

Sepsis screening tools for predicting infection triggers and outcomes in diabetic ketoacidosis

Background: An early prediction of infection is challenging in diabetic ketoacidosis (DKA). Methods: This prospective cohort study aimed to assess effectiveness of various sepsis screening tools in predicting infections and prognosis in DKA. Results: Among 141 cases, infection (44.0%) was the commonest precipitating factor. A Sequential Organ Failure Assessment score ≥4 showed high specificity (82.28%) and high positive likelihood ratio (2.64) but limited sensitivity (46.77%). Conversely, Systemic Inflammatory Response Syndrome ≥2 exhibited good sensitivity (95.16%) but a high false-positive rate (84.28%). National Early Warning Score ≥7 and Quick Sequential Organ Failure Assessment ≥2 had low sensitivity and specificity. These sepsis tools also demonstrated low prognostic accuracy for mortality. Conclusion: Sepsis screening tools have limited predictive accuracy for infections and mortality in DKA.

Antimicrobial Resistance Patterns Among Neonates Referred to Pediatric Emergency in North India: A Prospective Cohort Study

BACKGROUND

Sepsis is a leading cause of neonatal mortality worldwide, with a disproportionately high burden in low-income and middle-income countries. There is limited prospective data on microorganism profiles and antimicrobial resistance (AMR) in outborn newborns referred to pediatric emergency in developing countries. We aimed to assess the pathogen profile and AMR patterns in outborn neonates referred to the pediatric emergency at a tertiary care center.

METHODS

In this prospective cohort study, we enrolled neonates with suspected sepsis and sent blood or cerebrospinal fluid cultures. Neonates were followed up daily until discharge or death. The isolated organisms were identified and tested for antimicrobial susceptibility. Standard definitions were used to define multidrug resistance.

RESULTS

Between January 1, 2020, and December 31, 2020, 1072 outborn neonates with suspected sepsis were enrolled. The rate of proven sepsis was 223.6 (95% CI:198.7-248.4) per 1000 infants. Gram-negative sepsis was the most common (n = 107,10%), followed by gram-positive sepsis (n = 81,7.6%) and fungal sepsis (n = 67,6.3%). Coagulase-negative staphylococci (n = 69), Candida spp. (n = 68), Klebsiella spp. (n = 55), Acinetobacter spp . (n = 31) and Escherichia coli (n = 9) were the most common pathogens. Over two-thirds (68.6%) of pathogens were multidrug resistance, with an alarming prevalence in Klebsiella spp. (33/53, 62%), Acinetobacter spp. (25/30, 83%) and coagulase-negative staphylococci (54/66, 82%). In total, 124 (11.6%) neonates died in the hospital (13.3% of proven cases and 11.1% of culture-negative sepsis cases).

CONCLUSIONS

High sepsis burden and alarming AMR among neonates referred to tertiary care centers warrant urgent attention toward coordinated implementation of rigorous sepsis prevention measures and antimicrobial stewardship across all healthcare levels.

Microbial cell-free DNA detection: Minimally invasive diagnosis of infectious diseases

BACKGROUND

Detection of infectious diseases, especially among immunocompromised and patients on prolonged anti-microbial treatment, remains challenging, limited by conventional techniques with low sensitivity and long-turnaround time. Molecular detection by polymerase chain reaction (PCR) also has limited utility as it requires a targeted approach with prior suspicion of the infecting organism. Advancements in sequencing methodologies, specifically next-generation sequencing (NGS), have presented a promising opportunity to identify pathogens in cases where conventional techniques may be inadequate. However, the direct application of these techniques for diagnosing invasive infections is still limited by the need for invasive sampling, highlighting the pressing need to develop and implement non-invasive or minimally invasive approaches to improve the diagnosis of invasive infections.

OBJECTIVES

The objectives of this article are to explore the notable features, clinical utility, and constraints associated with the detection of microbial circulating cell-free DNA (mcfDNA) as a minimally invasive diagnostic tool for infectious diseases.

CONTENT

The mcfDNA detection provides an opportunity to identify micro-organisms in the blood of a patient. It is especially beneficial in immunocompromised patients where invasive sampling is not possible or where repeated cultures are negative. This review will discuss the applications and constraints of detecting mcfDNA for diagnosing infections and the various platforms available for its detection.

A fatal case of Aeromonas jandaei necrotizing fasciitis

Introduction

Necrotizing soft tissue infections (NSTIs) are associated with a fulminating course because of their rapid destruction of tissue planes underlying the skin. Aeromonas -associated monomicrobial NSTIs are usually associated with exposure to fresh water, particularly among agricultural workers and fish handlers. Albeit uncommon in incidence, urgent medical and surgical intervention are required once a diagnosis has been made.

Case report

A 40-year-old male patient, a known case of alcoholic liver disease, presented to the emergency department with pain and diffuse swelling of bilateral lower limbs, which quickly progressed to form blackish discolouration and blebs. Blood for preliminary haematological and biochemical investigations, as well as fluid draining from blebs, were sent for microbiological investigation. The Gram stain revealed occasional neutrophils and Gram-negative bacilli, and pure growth in aerobic culture was identified as Aeromonas jandaei by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The patient was started on empirical antimicrobials, although lesions continued to progress and he ultimately succumbed within 12 h of hospital admission.

Conclusion

As appropriate antimicrobial therapy and early surgical intervention are required for management of the same, occupational exposure and the fulminant course should raise suspicion of Aeromonas -associated infections.

Burden, risk factors, and outcomes of multidrug-resistant bacterial colonisation at multiple sites in patients with cirrhosis

Background & Aims

The reported burden of multidrug-resistant organism (MDRO) infections is highest in patients with cirrhosis from India. We evaluated whether colonisation at multiple barriers predisposes to such infections and poor outcomes in patients with cirrhosis.

Methods

We prospectively performed swab cultures, antimicrobial susceptibility testing (AST), and genotype testing for MDROs from various sites (rectum, nose, composite-skin, and central-line) in patients with cirrhosis (2020-2021) on admission and follow-up at a tertiary institute. We analysed clinical data, risk factors for MDROs, and patient outcomes.

Results

Of 125 patients aged 49 years, 85.6% males, 60.8% with acute-on-chronic liver failure, 99 (79.2%) were identified as 'colonisers'. MDRO-colonisation at rectum, nose, skin, or central line was observed in 72.7% (88/121), 30.0% (36/120), 14.9% (18/121), and 3.3% (4/121) patients, respectively. Patients were colonised with the following types of bacteria: extended-spectrum beta-lactamase (71/125), carbapenem-resistant Enterobacterales (67/125), MDR-Enterococcus (48/125), MDR-Acinetobacter (21/125), or methicillin-resistant Staphylococcus aureus (4/125). Multiple precipitants of acute-decompensation (odds ratio [OR]: 3.4, p = 0.042), norfloxacin prophylaxis (OR: 3.9, p = 0.008), and MDRO infection at admission (OR: 8.9, p = 0.041) were the independent predictors of colonisation. Colonisation increased the risk of infection by MDROs at admission (OR: 8.5, p = 0.017) and follow up (OR: 7.5, p <0.001). Although any-site colonisers were at greater risk of cerebral failure and poorer Child-Pugh scores, the nasal and skin colonisers were at higher risk of cerebral and circulatory failures than non-colonisers (p <0.05).Patients with more than one site colonisation (prevalence: 30%) developed multi-organ failure (p <0.05), MDRO infection (OR: 7.9, p <0.001), and poorer 30-day survival (hazard ratio: 2.0, p = 0.005).

Conclusions

A strikingly high burden of MDRO colonisation among patients with cirrhosis in India necessitates urgent control measures. Multiple-site colonisation increases the risk of MDR-infections, multi-organ failure, and mortality in patients with cirrhosis.

Impact and Implications

Infections by bacteria resistant to multiple antibiotics are an emerging cause of death in cirrhosis. We showed that ∼70-80% of critically ill hospitalised patients with cirrhosis carry such bacteria with the highest rate in the rectum, nose, skin, and central line port. Carbapenem-resistant and vancomycin-resistant bacteria were amongst the most common colonising bacteria. The presence of these bacteria at multiple sites increased the risk of multidrug-resistant infections, multiple organ failures, and death in patients with cirrhosis.

Role of fluoroquinolone prophylaxis in allogeneic hematopoietic cell transplantation in regions with a high prevalence of fluoroquinolone resistance

Introduction

The role of fluoroquinolone (FQ) prophylaxis in preventing gram-negative bacilli (GNB) bacteremia, graft-versus-host disease (GVHD), and overall survival (OS) after allogeneic hematopoietic cell transplantation (allo-HCT) is debatable and may differ in settings with low and high prevalences of FQ resistance. In this study, we aimed to answer this question in regions with high FQ resistance.

Methods

This single-center retrospective study included all consecutive allo-HCT recipients aged ≥12 years from 2012 to 2021. Allo-HCT recipients until 2016 were administered FQ prophylaxis (levofloxacin). After 2016, the institutional protocol was modified to no antibiotic prophylaxis. Data were retrieved from patient records for disease and transplant characteristics, the incidence of GNB bacteremia, duration of parenteral antibiotics, hospitalization duration, acute GVHD, and OS.

Results

A total of 135 allo-HCT recipients (43 in the FQ-prophylaxis cohort and 92 in the no-antibiotic prophylaxis cohort) were analyzed in this study. The two cohorts were matched for age (median, 26 vs. 24.5 years; p = 0.8). The no-antibiotic prophylaxis cohort had a higher proportion of malignant diagnoses (80% vs. 58%, p = 0.01), haploidentical transplants (46% vs. 14%, p = 0.004), and posttransplant cyclophosphamide exposure (46% vs. 14%, p = 0.003) than did the FQ cohort. Despite this, the incidence of GNB bacteremia was not significantly different between the two cohorts (37% vs. 34%, p = 0.6). There were no differences in parenteral antibiotic use or hospitalization duration, as well as the incidence of acute GVHD (53% vs. 53%, p = 0.3). The 1-year OS was similar between the two cohorts (66% vs. 67%, p = 0.6).

Conclusion

This study shows that FQ prophylaxis did not affect the incidence of GNB bacteremia, parenteral antibiotic use, hospitalization duration, acute GVHD, and OS post-allo-HCT.

Anaerobic Gram-Negative Bacteria: Role as a Reservoir of Antibiotic Resistance

BACKGROUND

Anaerobic Gram-negative bacteria (AGNB) play a significant role as both pathogens and essential members of the human microbiota. Despite their clinical importance, there remains limited understanding regarding their antimicrobial resistance (AMR) patterns. This knowledge gap poses challenges in effectively managing AGNB-associated infections, as empirical treatment approaches may not adequately address the evolving resistance landscape. To bridge this research gap, we conducted a comprehensive study aimed at exploring the role of human AGNB as a reservoir of AMR. This can provide valuable insights for the prevention and management of anaerobic infections.

METHODS

We studied the prevalence of AMR and AMR determinants conferring resistance to metronidazole (nimE), imipenem (cfiA), piperacillin-tazobactam (cepA), cefoxitin (cfxA), clindamycin (ermF), chloramphenicol (cat) and mobile genetic elements (MGEs) such as cfiA^IS and IS1186 associated with the cfiA and nim gene expression. These parameters were studied in Bacteroides spp., Fusobacterium spp., Prevotella spp., Veillonella spp., Sutterella spp., and other clinical AGNB.

RESULTS

Resistance to metronidazole, clindamycin, imipenem, piperacillin-tazobactam, cefoxitin and chloramphenicol was 29%, 33.5%, 0.5%, 27.5%, 26.5% and 0%, respectively. The presence of resistance genes, viz., nim, ermF, cfiA, cepA, cfxA, was detected in 24%, 33.5%, 10%, 9.5%, 21.5% isolates, respectively. None of the tested isolates showed the presence of a cat gene and MGEs, viz., cfiA^IS and IS1186. The highest resistance to all antimicrobial agents was exhibited by Bacteroides spp. The association between resistant phenotypes and genotypes was complete in clindamycin, as all clindamycin-resistant isolates showed the presence of ermF gene, and none of the susceptible strains harbored this gene; similarly, all isolates were chloramphenicol-susceptible and also lacked the cat gene, whereas the association was low among imipenem and piperacillin-tazobactam. Metronidazole and imipenem resistance was seen to be dependent on insertion sequences for the expression of AMR genes. A constrained co-existence of cepA and cfiA gene in B. fragilis species was seen. Based on the absence and presence of the cfiA gene, we divided B. fragilis into two categories, Division I (72.6%) and Division II (27.3%), respectively.

CONCLUSION

AGNB acts as a reservoir of specific AMR genes, which may pose a threat to other anaerobes due to functional compatibility and acquisition of these genes. Thus, AST-complying standard guidelines must be performed periodically to monitor the local and institutional susceptibility trends, and rational therapeutic strategies must be adopted to direct empirical management.

Meningitis Among Neonates with Suspected Sepsis Presenting to Pediatric Emergency

We aimed to assess the risk factors, clinical features and microbial profiles of meningitis in neonates with suspected sepsis referred to a pediatric emergency. Over 13 months, 191 neonates were enrolled, of whom 64 (33.5%) had meningitis. There were no significant differences in risk factors or clinical features between infants with and without meningitis. Ninety-three neonates (49%) had culture-positive sepsis (109 isolates). Candida spp. (n = 29), coagulase-negative staphylococci (n = 28) and Klebsiella pneumoniae (n = 23) were the most common pathogens. Forty-one (53%) bacteria were multidrug resistant.

Stenotrophomonas maltophilia: An Emerging Pathogen in Chronic Granulomatous Disease

Reports of infections with Stenotrophomonas maltophilia in primary immunodeficiency diseases are scarce. We report 3 children with chronic granulomatous disease (CGD) who developed infections due to S. maltophilia (1- septicemia and 2- pneumonia). We propose that CGD is a risk factor for the development of S. maltophilia infections and children with unexplained S. maltophilia infections need to be worked up for CGD.

Can beta-lactamase resistance genes in anaerobic Gram-negative gut bacteria transfer to gut aerobes?

The study was conceived with the hypothesis that human aerobic gut flora could act as a reservoir of ß-lactamases and contribute to the emergence of ß-lactam resistance by transferring ß-lactamase genes to resident anaerobes. Thus, we studied the repertoire of ß-lactam resistance determinants (ß-lactamases associated with aerobes and anaerobes) in Gram-negative anaerobes. The phenotypic resistance against ß-lactams and the presence of aerobic and anaerobic ß-lactamases were tested in Gram-negative anaerobic isolates (n = 200) by agar dilution method and targeted PCR, respectively. In addition, whole-genome sequencing (WGS) was used to study the ß-lactam resistance determinants in 4/200 multi-drug resistant (MDR) strains. The resistance to ß-lactams was as follows: imipenem (0.5%), cefoxitin (26.5%), and piperacillin-tazobactam (27.5%). None of the isolates showed the presence of ß-lactamases found in aerobic microorganisms. The presence of anaerobic ß-lactamase genes viz. cfiA, cepA, cfxA, cfiA^IS [the intact segment containing cfiA gene (350 bp) and upstream IS elements (1.6-1.7 kb)] was detected in 10%, 9.5%, 21.5%, and 0% isolates, respectively. The WGS data showed the presence of cfiA, cfiA4, cfxA, cfxA2, cfxA3, cfxA4, cfxA5 in MDR strains. The study showed a distinct dichotomy in repertoires of ß-lactamases between aerobes and anaerobes.

Mycotic aneurysm by Bacteroides fragilis presenting as fever of unknown origin

A mycotic aneurysm is an infection of the vessel wall which can be bacterial, fungal, or viral in origin. It is invariably a fatal infectious disease if appropriate treatment is not done. We describe the case of a forty-six years male who presented with complaints of high-grade fever and lower back pain with worsening symptoms with the passage of the illness. An infrarenal lobulated abdominal aortic aneurysm was confirmed by CT angiography. He underwent aneurysmorrhaphy and metronidazole was started following the culture report (Bacteroides fragilis). He was discharged successfully from the hospital.

In-vitro susceptibility testing methods for ceftazidime-avibactam against carbapenem-resistant Enterobacterales: Comparison with reference broth microdilution method

Introduction:

β-lactam antibiotics, mainly cephalosporins, and carbapenems, have been the mainstay of treatment for infections caused by Enterobacterales. However, their role in treating clinical infections has become limited because of the increase in resistance. There is a need to have cost-effective and rapid methods for antimicrobial susceptibility testing methods for newer antibiotics like ceftazidime-avibactam against carbapenem-resistant Enterobacterales (CRE), which can be applied in routine clinical microbiology laboratories. With this aim, the present study was conducted to compare the disk diffusion and gradient diffusion, i.e., the E-test method with the reference broth microdilution (BMD) method for in-vitro testing of ceftazidime-avibactam against CRE.

Material and Methods:

A total of 111 CRE isolates from various clinical samples were included. Conventional PCR (Polymerase Chain Reaction) was done for the detection of genes encoding carbapenemases and to see their expression, modified carbapenem inactivation method (mCIM) along with EDTA (Ethylenediaminetetraacetic acid) carbapenem inactivation method (eCIM) was done.

Results:

42.3% (47/111) isolates were resistant to ceftazidime-avibactam by the standard broth microdilution method; however, 45.9% (51/111) were resistant by both disk diffusion and E-test. In 5.4% of isolates (similar in both methods), microbroth dilution method results did not match with E-strip and disk diffusion. Very major errors (VME) by both disk diffusion and E-test were found in 2.1% (1/47), and major errors (ME) were found in 7.8% (5/64) isolates (similar isolates in both methods). The overall categorical agreement (CA) rate was 94.6% for both E-test and disk diffusion, and the essential agreement (EA) rate was 90.1% (100/111) for E-test. 98% (109/111) of CRE harbored carbapenemase genes either singly (30.3%) or in combination with others (69.7%).

Conclusion:

In conclusion, for CRE, E-test and the disk diffusion method for ceftazidime-avibactam depicted an acceptable performance as an alternative to the reference broth microdilution method.

Evaluation of ERIC-PCR and MALDI-TOF as typing tools for multidrug resistant Klebsiella pneumoniae clinical isolates from a tertiary care center in India

Background and aim

Multidrug resistant Klebsiella pneumoniae is associated with nosocomial infections in both outbreak and non-outbreak situations. The study intends to evaluate the potential of enterobacterial repetitive intergenic consensus- polymerase chain reaction (ERIC-PCR), a genomic based typing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) proteomic-based typing techniques for clonal relatedness among multidrug resistant Klebsiella pneumoniae isolates.

Methodology

Multidrug resistant clinical isolates of Klebsiella pneumoniae (n = 137) were collected from March 2019 to February 2020. Identification and protein-based phylogenetic analysis were performed by MALDI-TOF MS. Genomic typing was done by ERIC-PCR and analyzed by an online data analysis service (PyElph). Dice method with unweighted pair group method with arithmetic mean (UPGMA) program was used to compare the ERIC profiles. The samples were also evaluated by PCR for the presence of genes encoding carbapenemases, extended spectrum beta lactamases (ESBLs) and mobile colistin resistance-1 (mcr1).

Result and conclusion

The study presents ERIC-PCR as more robust and better discriminatory typing tool in comparison to MALDI-TOF for clonal relatedness in multidrug resistant K. pneumoniae clinical isolates. Isolates were typed into 40 ERIC types, and six groups by MALDI-TOF-MS. PCR-based analysis revealed that all the strains harbored two or more ESBL and carbapenemase genes. None of the isolates revealed the presence of the plasmid mediated mcr-1 gene for colistin resistance.

Systematic review of ultrasound gel associated Burkholderia cepacia complex outbreaks: Clinical presentation, sources and control of outbreak

BACKGROUND

Burkholderia cepacia complex (Bcc) is an emerging opportunistic pathogen among immunocompromised patients. It frequently contaminates saline, fluids and ultrasound (US) gel used in hospitals. This systematic review was conducted to analyze Bcc outbreaks due to ultrasound (US) gel for better management of these outbreaks.

METHODS

As per PRISMA guidelines, electronic databases "Embase" and "Pubmed" and "Web of sciences" were searched from 1991 to April, 2021 to identify studies causing Burkholderia spp outbreak due to contamination of US gels.

RESULTS

The search identified 14 outbreak reports that met our inclusion criteria. Bacteremia was the most common clinical presentation in ten studies followed by urinary tract infections in 4 studies. In most of the studies B. cepacia was the most common isolated organism. Other members like B. ambifaria, B. contaminans, and B. stabilis caused outbreaks in two studies. Pulsed field gel electrophoresis and multilocus sequence typing were commonly employed methods to study the clonal association. In 8 outbreaks, intrinsic contamination of the gel, that is, contamination from manufacturing site, was present and 4 studies, extrinsic contamination, that is, contamination from environment was responsible for outbreak.

CONCLUSION

This review highlights the importance of US gel as a source of outbreak in health-care facilities. Ensuring sterility of US gel, sound epidemiological investigation of outbreak and prompt response by infection control team can prevent these outbreaks.

The potential of 4D's approach in curbing antimicrobial resistance among bacterial pathogens

INTRODUCTION

Antibiotics are life-saving drugs but irrational/inappropriate use leads to the emergence of antibiotic-resistant bacterial superbugs, making their treatment extremely challenging. Increasing antimicrobial resistance (AMR) among bacterial pathogens is becoming a serious public health concern globally. If ignorance persists, there would not be any antibiotics available to treat even a common bacterial infection in future.

AREA COVERED

This article intends to collate and discuss the potential of 4D's (right Drug, Dose, Duration, and De-escalation of therapy) approach to tackle the emerging problem of AMR. For this, we searched PubMed, Google Scholar, Medline, and clinicaltrials.gov databases primarily using keywords 'optimal antibiotic therapy,' 'antimicrobial resistance,' 'higher versus lower dose antibiotic treatment,' 'shorter versus longer duration antibiotic treatment,' 'de-escalation study', and 'antimicrobial stewardship measures' and based on the findings, form and expressed our opinion.

EXPERT OPINION

More efforts are needed for developing diagnostics for rapid, accurate, point-of-care, and cost-effective pathogen identification and antimicrobial susceptibility testing (AST) to facilitate rational use of antibiotics. Current dosing and duration of therapies also need to be redefined to maximize their impact. Furthermore, de-escalation approaches should be developed and encouraged in the clinic. This altogether will minimize selection pressure on the pathogens and reduce emergence of AMR.

Emerging Bacterial Pathogens in the COVID-19 Era: Chryseobacterium gleum—A Case in Point

Introduction In the ongoing severe acute respiratory syndrome coronavirus 2 pandemic, a long hospital stay and empirical broad-spectrum antibiotics make the patients prone to acquire nosocomial infections especially with unconventional organisms, and Chryseobacterium gleum is one such rare nosocomial pathogen.

Methods The given study is a case-series-based study conducted from September 2020 to April 2021 in which clinically suspected pneumonia patients who recovered from coronavirus disease 2019 (COVID-19) were included.

Results Seventeen C. gleum isolates were obtained in pure culture from the tracheal aspirates of nine COVID-19 patients (including repeat samples to rule out colonization) within a period of eight months (September 2020–April 2021). Our records showed that there has been an increase in the number of isolates of C. gleum obtained in respiratory samples in 2020. We also did a review of literature of all the cases of C. gleum pneumonia reported till now.

Conclusion To the best of our knowledge, this is the first study reporting the isolation of this rare pathogen from COVID-19 patients with clinical significance in a large cohort of patients. Therefore, it becomes important to consider this pathogen as a significant cause of respiratory infections, especially in patients recovered post COVID-19.

Polymicrobial infection presenting as non-clostridial gas gangrene in a non-diabetic trauma patient. A case report and review of literature

BACKGROUND

Clostridium species are known to be the primary causative organism of gas gangrene. Non-clostridial gas gangrene (NCGG) is another rare necrotizing entity often associated with an underlying disease, particularly diabetes mellitus, and has a high mortality rate.

CASE REPORT

A 16-year-old, immunocompetent male was referred to us after four days, following a roadside accident, with a degloving injury over the thigh and knee along with fractures around the knee. Although clinico-radiologically suspicious of gas gangrene, the initial smear report was negative for any Gram-positive bacilli. On the same day, he underwent aggressive debridement with an external fixator spanning the knee to salvage the limb. On post-operative day one, due to deteriorating general clinical condition and a strong clinical suspicion of gas gangrene, he underwent above-knee amputation (open stump) after discussion with microbiologists and physicians.

RESULTS

Polymicrobial non-clostridial infection was seen in culture reports taken serially at different stages of management. The latest follow-up showed a healed amputation stump following split skin grafting.

CONCLUSION

Although rare, polymicrobial infections can present as non-clostridial gas gangrene even in an immunocompetent patient. A high index of clinical suspicion with a multi-disciplinary approach helps in early decision-making to avoid a devastating outcome.

Comparative evaluation of phenotypic and genotypic methods for the rapid and cost-effective detection of carbapenemases in extensively drug resistant Klebsiella pneumoniae

PURPOSE

Carbapenemases are the enzymes that can hydrolyze carbapenems and other β-lactam antibiotics. These enzymes confer resistance to multiple antibiotics and act as a stumbling block in the treatment of infections caused by gram-negative bacteria. Therefore, rapid and specific detection of these enzymes is crucial for deciding the course of treatment and better clinical outcomes.

MATERIAL AND METHODS

This study was conducted to compare various phenotypic and PCR based methods for the detection of carbapenemases in carbapenem- and colistin-resistant Klebsiella pneumoniae. One hundred clinical isolates of extensively resistant Klebsiella pneumoniae were included in the study. Phenotypic detection for carbapenemases was performed by Rapidec® Carba NP (Biomerieux), modified carbapenem inactivation method (mCIM), imipenem-ethylenediaminetetraacetic acid disk synergy (EDS), double disk synergy test using mercaptopropionic acid (DDST-MPA), and combined disk method (CD) and for colistin by microbroth dilution method. Genotypic detection for carbapenemases and colistin resistance was performed by targeted PCR.

RESULTS

The sensitivity of Carba NP test and mCIM were positive in 95% and 96% respectively and specificity was 100% for both methods. The sensitivity of EDS, DDST-MPA, and CD were 55.6%, 88.9% and 54.5% respectively. Among the carbapenem resistance genes, blaOXA-48 (82%) genes were the most prevalent. Among metallo-beta lactamases, blaVIM (56%) was most common followed by blaNDM (54%) and blaIMP (20%). The mcr-1 gene for colistin resistance was not detected in any isolate.

CONCLUSION

Among the five phenotypic assays analyzed, the mCIM is the most simple, inexpensive, accurate and reproducible method for carbapenemase detection in Klebsiella pneumoniae. The DDST-MPA test provides the best sensitivity for the detection of carbapenemases, although specificity is low. These tests, when applied in a clinical laboratory and assessed by the microbiologist, can help in guiding the course of treatment.

P105 In vitro interaction of Malassezia and commensal Staphylococcus species

 

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM

Objective

Malassezia is the most abundant fungal skin commensal organism, representing 50%–80% of total fungi present on the skin. It has been associated with many skin disorders such as pityriasis versicolor (PV) and seborrheic dermatitis/dandruff (SD/D). The role of Malassezia in disease manifestation is not discerned. It is important to understand its interaction with bacterial flora such as Staphylococcus epidermidis and S. capitis in vitro. We have studied the interaction of Malassezia and Staphylococcus species isolated from skin flora.

Methods

Malassezia restricta, M. globosa (n = 5) isolated from patients with SD and M. furfur (n = 5) isolated from PV were sub-cultured on Modified Dixon's agar (MDA). Staphylococcus epidermidis and S. capitis were isolated from patients with SD and sub-cultured on brain heart infusion (BHI) agar. Malassezia species requires media supplemented with lipids (MDA) for its growth. Bacteria and Malassezia were quantified on MDA and BHI agar by Miles and Mishra method to perform interaction between them. For direct interaction, suspensions (100 μl) of M. restricta, M. globose, and M. furfur were prepared in normal saline and added to wells on the plates of lawn cultures containing S. epidermidis and S. capitis (107 CFU/ml). Plates were incubated for 12 h at 35°C and observed for zone of inhibition. To investigate the release of antibacterial compounds into the extracellular environment, M. furfur was inoculated in modified Dixon's broth (MDB) and incubated at 35°C for 5 days. Supernatant was collected at 12 h, 24 h, 48 h, 72 h, 96 h, and 120 h of incubation and evaluated for antibacterial activity by agar-well diffusion assay. Effect of cell-free supernatant of Malassezia on growth of bacteria was also monitored by growth kinetics of S. epidermidis for 24 h in the absence and presence of M. furfur supernatant using Epoch-2 microplate spectrophotometer.

Results

MDA supported the growth of bacteria at different cell densities (107-103 CFU/ml count) and incubation time of S. epidermidis and S. capitis was similar on MDA and BHI. Zone of inhibition (ZOI) was witnessed with M. restricta (20.6 ± 3 mm, 21 ± 3 mm), M. globosa (21 ±1 mm, 22.6 ±2 mm) and M. furfur isolates (16.5 ± 1 mm, 18 ± 2 mm) against S. capitis and S. epidermidis respectively by direct interaction. Inhibition of bacteria by M. furfur was noted from 48-120 h as ZOI (21.7 ±5.1 mm) was observed on bacterial lawn cultured plate. When growth kinetics of S. epidermidis was monitored in presence of M. furfur supernatant, maximum value reached upto 0.26 ± 0.019 only from 0.01 ± 0.001 at OD600 in 9 h including lag phase of 4 h (Fig. 1). However, OD600 value reached upto 0.97 ± 0.005 in 8 h including lag phase of 1.5 h in absence of supernatant. Doubling time calculated from logistic growth equation was 76.6 ± 4.4 and 65.2 ± 2.9 minutes in the presence and absence of supernatant respectively.

Conclusion

Inhibition of bacteria by Malassezia species noted in our study has not been reported earlier. The possible production of antibacterial compounds by Malassezia might be responsible for dysbiosis leading to disease.

Extensive Multifocal Emphysematous Osteomyelitis of Spine: A Rare Case and a Review of Literature

BACKGROUND

Emphysematous osteomyelitis (EO) is an extremely rare form of osteomyelitis which is complicated mainly by infection with gas-forming organisms. The common causative agents of this disease are mainly members of Enterobacteriaceae family, the most common are Escherichia coli and Klebsiella pneumoniae along with anaerobes. A total of 48 cases of EO have been reported in the literature till now globally and none have documented the isolation of Corynebacterium amycolatum.

CASE PRESENTATION

We report a rare case of emphysematous osteomyelitis of the spine and pelvis due to Escherichia coli along with the isolation of Corynebacterium amycolatum from the same pus samples on two consecutive occasions in a 50-year-old female with uncontrolled diabetes mellitus, who was successively treated with antibiotics and drainage of pus. We also did a brief review of the literature of all cases reported till now.

CONCLUSION

The role of Corynebacterium amycolatum in the etiology of emphysematous osteomyelitis needs to be evaluated further in future studies as we cannot completely ignore its isolation in two consecutive samples as a mere contaminant.

Cluster outbreak of Pseudomonas stutzeri acute endophthalmitis following phacoemulsification: A report of 14 cases from North India

Purpose:

To report clinical features, antibiotic susceptibility profile, management, and outcomes of a cluster outbreak of post-cataract surgery Pseudomonas stutzeri endophthalmitis.

Methods:

This was a hospital-based case series in which 14 patients with acute postoperative endophthalmitis who underwent cataract surgery on the same day were included. Based on severity of presentation, they either underwent pars plana vitrectomy (PPV) with intraocular antibiotics (IOAB) or vitreous tap with IOAB. Vitreous aspirates and environmental surveillance samples were inoculated on culture media and further processed by MALDI-TOF MS for identification and Vitek3 for susceptibility profile.

Results:

There were 8 females and 6 males with a mean age of 62.14 ± 8.08 years. Presenting signs included corneal folds (100%), hypopyon (57.1%) and fibrin (50%). Ten patients with mild presentation underwent vitreous tap with IOAB. Four patients with severe presentation underwent PPV with IOAB. Pseudomonas stutzeri was isolated from the vitreous samples and was pan-sensitive. Six eyes required multiple interventions. Favorable outcome was obtained in 12 eyes, one eye developed phthisis, and one patient was lost to follow-up.

Conclusion:

We report the first ever cluster outbreak of Pseudomonas stutzeri endophthalmitis following phacoemulsification with IOL implantation in a single surgeon setting. Majority of the patients had a mild presentation and responded well to targeted anti-microbial treatment.

Colonization of the central venous catheter by Stenotrophomonas maltophilia in an ICU setting: An impending outbreak managed in time

BACKGROUND

Stenotrophomonas maltophiliacauses opportunistic infections in immunocompromised and patients in intensive care units (ICUs). An outbreak of S. maltophilia in ICU is described which highlights the importance of the risk of infection from contaminated medical devices and suction fluids in ventilated patients.

METHODS

The investigation of the outbreak was carried out. Environmental sampling was done. This was followed by MALDI-TOF MS typing and recA gene-based-phylogeny.

RESULTS

In February, S. maltophilia was reported from the central line blood of six patients from ICU within a span of two weeks. The peripheral line blood cultures were sterile in all patients. Relevant environmental sampling of the high-touch surface and fluids revealed S. maltophilia strains in normal saline used for suction and in the inspiratory circuit of two patients. The isolated strains from patients and environment (inspiratory fluid) showed a minimum of 95.41% recA gene sequence identity between each other. Strict cleaning and disinfection procedures were followed. Continuous surveillance was done and no further case of S. maltophilia was detected. Timely diagnosis and removal of central line prevented development of central-line associated blood stream infection.

CONCLUSION

This outbreak report illustrates that environmental sources like suction fluid and normal saline could be the source of S. maltophilia in ICU patients.

Effect of Reuse of Insulin Needle on Glycaemic Control and Related Complications in Children with Type 1 Diabetes Mellitus: A Prospective Observational Study

BACKGROUND

Children with type 1 diabetes (T1D) take multiple subcutaneous injections of insulin daily to survive. It is controversial whether the insulin needles can be reused safely or not. This study assesses the effect of the reuse versus single-use of insulin needle on glycaemic control and injection-related complications.

METHODS

Nearly 121 children (<15 years) with T1D were prospectively observed for existing practice of needle reuse for first 3 months and then were asked to practice single-use for the next 3 months.

RESULTS

It was found that 78% participants were reusing needles more than three times. After 3 months of needle reuse, 91.3% patients had lipodystrophy. Frequency of reuse positively correlated with local redness, bleeding and leakage of insulin. The patients achieving HbA1c ≤7.5% was significantly low among those reusing needles more than four times. After 3 months of single-use, no significant difference was found in mean HbA1c. However, hyperglycaemic episodes, lipodystrophy and local complications reduced significantly. There was a significant reduction in mean HbA1c among those using needles more than six times earlier.

CONCLUSION

Reuse of insulin needles up to six times does not affect the glycaemic control significantly. To achieve target HbA1c (<7.5%) the needle reuse should be restricted to three times only, which can also reduce injection-related local complications.

Association of Intra-Operative Bile Culture with Post-Operative Complications after Pancreaticoduodenectomy

Background: Infectious complications after pancreaticoduodenectomy (PD) are a major cause of morbidity. The association of bactibilia with the occurrence of surgical site infection (SSI) is debatable. Patients and Methods: Consecutive patients who underwent PD between July 2019 and December 2020 were included. All patients underwent standard pre-operative preparation and imaging. Pre-operative biliary drainage (PBD) was done as clinically indicated. A bile sample was collected just before the transection of common bile duct (CBD). Post-operative outcomes including SSI were analyzed. Results: Fifty-four patients were assessed for enrollment; 50 were found to be resectable during surgery and were included. The incidence of bactibilia was 46%. Nineteen (38%) patients developed SSIs and the occurrence was higher in patients who had positive bile culture (14 [60.8%] vs. 5 [18.5%]; p = 0.002). A similar organism between bile culture and SSI was seen in nine (64.2%) of 14 patients. Patients who had positive bile culture had more frequent change of antibiotic (16 [69%] vs. 8 [29.6%]; p = 0.005) and required prolonged duration of postoperative antibiotic agents (12 days [IQR, 8-14] vs. 8 days [IQR, 6-10]; p = 0.003). There was no association between bile culture growth and development of post-operative pancreatic fistula, delayed gastric emptying, and post-operative pancreatic hemorrhage. Patients with bactibilia had prolonged post-operative stay (17 days [IQR, 11-20] vs. 11 days [IQR, 8-14]; p = 0.010) and severe post-operative complications (8 [34.7%] vs. 2 [7.4%]; p = 0.008). Conclusions: Bactibilia is associated with the development of SSI and may provide a guide in selection of antibiotics.

Globicatella sanguinis corneal abscess with endophthalmitis

Globicatella sanguinis is a rare microorganism known to affect the bloodstream, urinary tract, and central nervous system. We report a case of Globicatella sanguinis ocular infection in a 9-year-old boy, who presented with a corneal abscess with endophthalmitis, following trauma. Isolation of the infection using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and determination of its antibiotic sensitivity via Vitek 2 highlight the important role of microbiology laboratories for the diagnosis and management of infections caused by atypical microorganisms.

Secondary anaerobic infection in a case of multidrug resistant tubercular paraspinal abscess: A rare presentation

Introduction

Paraspinal abscesses are most commonly caused by Staphylococcus aureus and some Gram-negative bacteria. In developing countries, Mycobacterium tuberculosis (MTB) contributes to almost 50 % of cases. Even in proven cases of tubercular paraspinal abscesses, secondary infection of aerobic or anaerobic bacteria is possible and should be carefully evaluated for proper management.

Case report

A type I diabetes mellitus patient presented with chronic backache and lower limb weakness and radiological investigations showed paraspinal collections suggestive of tuberculosis. The patient was then started on anti-tubercular drugs, she initially responded and then showed gradual deterioration in the form of increased pain, fever and pus discharge. Aerobic cultures of pus were sterile and anaerobic culture grew Peptoniphilus asaccharolyticus sensitive to metronidazole. Appropriate treatment had resulted in clinical improvement.

Conclusion

Suspicion about co-infection with aerobic or anaerobic bacteria should be high even in proven cases of tubercular paraspinal abscess not improving despite proper anti-tubercular therapy.

Changing spectrum of infective endocarditis in India: An 11-year experience from an academic hospital in North India

Objective

Several studies have demonstrated a shift in the spectrum of infective endocarditis (IE) in the developed world. We aimed to investigate whether demographic and microbiologic characteristics of IE have changed in India.

Design

A retrospective analysis of patients with in north India between 2010 and 2020.

Methods

The clinical and laboratory profiles of 199 IE admitted to an academic hospital patients who met the modified Duke criteria for definite IE were analysed.

Results

The mean age was 34 years, and 84% were males. The main predisposing conditions were injection drug use (IDU) (n = 71, 35.7%), congenital heart disease (n = 46, 21.6%), rheumatic heart disease (n = 25, 12.5%), and prosthetic device (n = 19, 9.5%). 17.1% of patients developed IE without identified predispositions. Among 64.3% culture-positive cases, the most prevalent causative pathogens were Staphylococcus aureus (46.1%), viridans streptococci (7.0%), enterococci (6.0%), coagulase-negative staphylococci (5.5%), gram negative bacilli (5.5%), polymicrobial (5.5%), and Candida (1.0%). The tricuspid (30.3%), mitral (25.6%), and aortic (21.6%) valves were the most common sites of infection, and 60.3% had large vegetations (>10 mm). Systemic embolization occurred in 55.3% of patients at presentation. Cardiac surgery was required for 13.1%. In-hospital mortality was 17.1% and was associated with prosthetic devices (p-value, 0.001), baseline leucocytosis (p-value, 0.036) or acute kidney injury (p-value, 0.001), and a microbial etiology of gram negative bacilli or enterococci (p-value, 0.005).

Conclusion

IDU is now the most important predisposition for IE in India, and S. aureus has become the leading cause of native valve endocarditis with or without IDU.

Clinical anaerobic infections in an Indian tertiary care hospital: A two-year retrospective study

OBJECTIVE

To study the spectrum of anaerobic infections and the frequency of clinically relevant anaerobes in various infections in a tertiary care hospital in North India.

METHOD

In this two-year (2018-2019) retrospective study, a total of 22,177 samples were processed both anaerobically and aerobically. The samples included blood, pus, body fluids, necrotic tissues, abscess, peritoneal fluids, and other specimens of conditions predisposing to anaerobic infections. The recovered bacterial isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

RESULT

Of the 22,177 samples processed anaerobically, 1094 showed significant anaerobic growth yielding 1464 anaerobes. Bacteroides fragilis (12.7%) and Peptoniphilus harei (12.2%) were the most predominant anaerobes, whereas Escherichia coli (32.6%) and Staphylococcus aureus (13.2%) were the most frequently recovered facultative anaerobes in polymicrobial growth. Both aerobic and anaerobic data were available for 673/1094 samples, of which 68% represented a polymicrobial etiology and 32% as monomicrobial. Of the cases where complete clinical information was available (504/1094), the majority of the anaerobes were recovered from the skin and soft tissue infections (36.3%) and intra-abdominal infections (17.1%). The clinical specimen most frequently growing anaerobes was abscess (29.1%), followed by diabetic foot ulcers (14.1%).

CONCLUSION

The study documents the frequency of clinically significant anaerobic bacteria in various infections, and their associations with aerobes in polymicrobial growth. The present study may aid us in devising better therapeutic strategies against both aerobes and anaerobes in anaerobic infections, which is often empirical. Besides, the data can update clinicians with the changing patterns of anaerobic infections, which remains a neglected concern.

Factors affecting decontamination of N95 masks for reuse: Feasibility & practicality of various methods

The SARS-CoV-2 pandemic has led to an enormous increase in cases worldwide in a short time. The potential shortage might call for the reuse of personal protective equipment especially N95 masks. In this review, the methods available for decontamination of N95 masks have been compared to highlight the advantages and efficacies of different methods. Studies conducted to evaluate the biocidal efficacy, effect on filtration efficacy of the decontamination method, and maintenance of structural integrity of masks, were reviewed. Ultraviolet germicidal irradiation (UVGI) and hydrogen peroxide (H2O2) vapour were the most commonly evaluated interventions and showed good germicidal activity without significant deleterious effects on mask performance. Vapourous H2O2 was the best method as it maintained NIOSH (The National Institute for Occupational Safety and Health) recommendations of the mask on re-use and additionally, one mask could be decontaminated and reused 30 times. Ethylene oxide (EtO) preserved the maximum filtration efficacy and flow resistance. Chemical and heat-based methods had the advantages of being cost-effective and feasible but affected the structural integrity and fit of the masks. For the decontamination of N95 masks, among the heat-based methods steam was found to be the best for low middle-income countries setting. H2O2-based methods, UVGI, and EtO all exhibited both adequate biocidal efficacies and functionality (fit testing and structural integrity). Further studies on logistics, healthcare worker acceptability of reuse, and actual efficacy of protection against SARS-CoV-2 infection should be carried out to validate the use of decontamination in the real-life settings.

Bacterial coinfections and secondary infections in COVID-19 patients from a tertiary care hospital of northern India: Time to adhere to culture-based practices

OBJECTIVE

Bacterial co-pathogens are common in various viral respiratory tract infections, leading to increased disease severity and mortality. Still, they are understudied during large outbreaks and pandemics. This study was conducted to highlight the overall burden of these infections in COVID-19 patients admitted to our tertiary care hospital, along with their antibiotic susceptibility patterns.

MATERIAL AND METHODS

During the six-month study period, clinical samples (blood samples, respiratory samples, and sterile body fluids, including cerebrospinal fluid [CSF]) of COVID-19 patients with suspected bacterial coinfections (at presentation) or secondary infections (after 48 hours of hospitalization) were received and processed for the same.

RESULTS

Clinical samples of 814 COVID-19 patients were received for bacterial culture and susceptibility. Out of the total patient sample, 75% had already received empirical antibiotics before the samples were sent for analysis. Overall, 17.9% of cultures were positive for bacterial infections. Out of the total patients with bacterial infection, 74% (108/146) of patients had secondary bacterial infections (after 48 hours of hospitalization) and 26% (38/146) had bacterial coinfections (at the time of admission). Out of the 143 total isolates obtained, the majority (86%) were gram-negative organisms, of which Acinetobacter species was the commonest organism (35.6%), followed by Klebsiella pneumoniae (18.1%). The majority (50.7%) of the pathogenic organisms reported were multidrug resistant.

CONCLUSION

The overall rate of secondary bacterial infections (SBIs) in our study was lower (7.9%) than reported by other studies. A rational approach would be to adhere to the practice of initiating culture-based guidance for antibiotics and to restrict unnecessary empirical antimicrobial therapy.

Skull base osteomyelitis by Pandoraea apista: An unusual pathogen at unusual location - A case report

Background:

Pandoraea apista is predominantly recovered from the respiratory tract of patients with cystic fibrosis (CF). Authors report first case of central nervous system infection by P. apista in the form of skull base osteomyelitis.

Case Description:

A 67-year-old male presented with complaints of earache and hearing deficit for few months. The radiology was suggestive of skull base osteomyelitis and polypoidal soft tissue extending from the middle cranial fossa to the infratemporal fossa. The sample from the targeted area revealed P. apista on matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. With adequate antibiotic therapy, there was clinicoradiologic improvement. P. apista is an infection exclusively seen in pulmonary infection in patients with CF. We identified its intracranial involvement in a patient for the 1^st time in the literature. The serendipitous diagnosis needs evaluation on specific PCR and matrix-assisted laser desorption spectrometry. The treatment with antibiotics provides a definite cure.

Conclusion:

We report a rare opportunistic infection with central nervous system involvement which can be cured by accurate diagnosis and appropriate antibiotic treatment.

Anaerobic infections in patients admitted in various surgical units of a tertiary care hospital of north India: neglected but important

Background and Objectives:

Anaerobic infections are usually caused by the host’s endogenous flora due to a breach in the anatomical barriers and Bacteroides spp. are the most notorious organisms associated with anaerobic infections. The identification of anaerobes has been a challenge since times. MALDI-TOF-MS is a boon for aiding the rapid detection of anaerobic organisms and has helped us to enlist the distribution of various anaerobic pathogens.

Materials and Methods:

This retrospective analysis (January 2018 to December 2019) was carried out in a tertiary care hospital in North India, in which the anaerobic microbiological profile of all patients admitted to surgical wards, ICU, and OPD of various departments (Orthopedics, Surgery, Gynecology, and Obstetrics) was reviewed. Samples received were immediately processed aerobically (5% sheep blood agar and Mac Conkeyagar) as well as anaerobically (RCM and freshly prepared sheep blood agar) as per the laboratory protocols.

Results:

Bacteroides fragilis (19.12%) was the most common anaerobe whereas among aerobes Escherichia coli (30.2%) followed by Klebsiella pneumoniae (10.34%) were most commonly isolated. The majority of patients were males (56%) and the most common presentation was with abscesses (21.4%). Polymicrobial infections (69.51%) outnumbered monomicrobial ones (30.48%).

Conclusion:

There is a paucity of literature on anaerobe isolation from surgical infections from our country which motivated us to study anaerobic infections and the high sample size in our institute enabled us to study surgical infections from an anaerobic perspective. This will add to the knowledge of microbiologists and clinicians. MALDI-TOF MS helped in rapid and accurate identification and hence we could report a wider spectrum of organisms in our study.

Comparative evaluation of agar dilution and broth microdilution by commercial and in-house plates for Bacteroides fragilis group: An economical and expeditious approach for resource-limited settings

OBJECTIVE

To compare the performance of agar dilution and broth microdilution by commercial and in-house prepared plates for the Bacteroides fragilis group. The cost analysis was performed to demonstrate that in-house prepared BMD plates were a suitable alternative to agar dilution given the high cost and low feasibility of incorporating commercial BMD plates in routine, particularly in the tertiary care institutes of many low- and middle-income countries.

METHODS

Thirty B. fragilis group isolates were tested against six antibiotics, frequently used as empirical therapy for anaerobic infections including metronidazole, clindamycin, imipenem, piperacillin-tazobactam, cefoxitin, and chloramphenicol. The running consumable expenditure for all methodologies was calculated.

RESULTS

The results demonstrated essential and categorical agreement of >90% for all antibiotics except cefoxitin, which showed <90% categorical agreement. No major or very major errors were observed. We observed a high agreement and strong concordance for MIC values between both methods and inter-rate reliability of >0.9 by Cohen's kappa analysis, indicating almost perfect agreement between both methods using either of the plates. In contrast to agar dilution, a 20.5 fold cost reduction was seen in BMD using in-house plates and a 5.8 fold reduction using commercial plates to test a single isolate. However, when testing 30 isolates concurrently the cost significantly increased for commercial BMD plates by 8.4 folds, and only 1.03 fold cost reduction was seen with in-house BMD plates.

CONCLUSION

BMD gives comparable results to agar dilution and can be considered a method of choice to test a small number of samples. The technique is an economical option when plates are standardized in-house and could be employed for susceptibility testing of the B. fragilis group.

Phenotypic and genotypic antimicrobial resistance in clinical anaerobic isolates from India

BACKGROUND

Antimicrobial resistance (AMR) in anaerobes remains a neglected field. The laborious procedures, non-compliance with the standard methodology and differences in interpretive breakpoints add variation in resistance data.

OBJECTIVES

To assess the phenotypic and genotypic resistance among clinically important anaerobes to six antibiotics frequently used as empirical therapy for anaerobic infections.

METHODS

A total of 150 anaerobic isolates were recovered from clinical specimens. The antimicrobial susceptibility was determined by the breakpoint agar dilution method as per CLSI guidelines. The presence of genes encoding resistance to metronidazole (nim gene), imipenem (cfiA gene) and mobilizable insertion sequence (IS) elements was detected to comprehend their association with phenotypic resistance.

RESULTS

This is a first study of its kind from the Indian subcontinent looking at the AMR and associated genes in anaerobes. Resistance to metronidazole, clindamycin, imipenem, piperacillin/tazobactam and cefoxitin was 32.6%, 42.6%, 0.6%, 38% and 35.3%, respectively. No resistance was observed to chloramphenicol. The nim gene was detected in 24.6% of isolates, of which 70.2% were resistant by phenotype. On sequencing, the PCR products of six random nim genes showed a close similarity to nimE of Bacteroides fragilis with 99% nucleotide and 100% amino acid sequence similarity. The cfiA gene, associated with imipenem resistance, was detected in 16% of isolates.

CONCLUSIONS

The possibility of isolates carrying AMR genes to become resistant to antibiotics by acquisition of IS elements mandates attention to periodically monitor the resistance patterns and geographic distribution of these genes and IS elements to understand the trends of AMR in anaerobes.

Detection of co-infection of Gardnerella vaginalis and Atopobium vaginae using qualitative PCR: A better predictor of bacterial vaginosis

The present study aimed to determine the utility of detection of co-infection of Gardnerella vaginalis and Atopobium vaginae using qualitative PCR for diagnosing bacterial vaginosis (BV). Vaginal samples (n = 385) categorized as positive (n = 108) or negative (n = 208) for bacterial vaginosis based on the Nugent scoring system, were analyzed for the presence of G. vaginalis and A. vaginae by conventional PCR. We compared the sensitivity, specificity, positive predictive value, negative predictive value and odds ratio for the detection of each bacterium alone with the combination of the two bacteria for diagnosing BV. The detection of co-infection of the two bacteria demonstrated a sensitivity of 96%, a specificity of 82.9%, a positive predictive value of 68.5%, a negative predictive value of 98.2% with an odds ratio of 116 (CI -32 - 409). In our study, we found a high sensitivity, specificity, negative predictive value and odds ratio for the detection of co-infection of A. vaginae and G. vaginalis for the diagnosis of BV.