Diagnostic Accuracy of Endotoxin and Endotoxin Binding Protein in Late-Onset Neonatal Sepsis

OBJECTIVES

To evaluate the diagnostic utility of endotoxin and endotoxin binding protein (EBP) for the diagnosis of late-onset neonatal sepsis (LOS) and compare it with the diagnostic utility of C-reactive protein (CRP).

METHODS

This diagnostic study of neonates, both term and preterm, with clinical suspicion of LOS was conducted in a tertiary care institute in India between January 2021 and March 2023. Blood samples were collected for evaluating endotoxin and EBP along with culture. Endotoxin and EBP were measured with enzyme linked immunosorbent assay, CRP was measured by nephelometry method, and the results were compared with blood culture done with BACTEC (gold standard).

RESULTS

Out of 160 samples, 73 showed culture positivity. Endotoxin was positive in 81 samples and showed sensitivity of 84%, specificity of 78% and diagnostic accuracy of 81% (AUC 0.837, P value <0.001). EBP was positive in 82 samples and showed sensitivity of 80.8%, specificity of 73% and diagnostic accuracy of 76% (AUC 0.824, P value <0.001). CRP was positive in 105 samples and had sensitivity of 86%, specificity of 51% and diagnostic accuracy of 67% (AUC 0.827, P value <0.001).

CONCLUSIONS

The present study showed endotoxin and EBP have higher specificity for diagnosing neonatal sepsis. As culture takes minimum 48 h, endotoxin and EBP can be utilized as biomarkers for diagnosis of sepsis.

Efficacy of chlorhexidine/herbal formulation for microbial reduction in aerosol generated following ultrasonic scaling - A double-blinded randomized controlled trial

Background

Ultrasonic scaling is a potential source of aerosol contamination in dental clinics. The two primary sources of microbial load in aerosols are from the oral cavity and dental unit water line. Literature evidence suggest that the use of preprocedural mouth rinse reduce the bacterial load in aerosol generated during ultrasonic scaling.

Aim

The aim of the study is to assess the comparative efficacy of reduction in viable bacteria in the aerosol at patient's chest area, doctor's mask area and two feet beside the patient following use of chlorhexidine/herbal formulation diluted in the water source by a randomized controlled clinical trial.

Materials and Methods

Forty-five subjects (with chronic gingivitis) were matched for age, gender, and gingival index score. The subjects were randomized and received ultrasonic scaling with distilled water (control)/chlorhexidine (tTest)/herbal formulation (test). Aerosol produced during scaling was collected at patient's chest area, doctor's mask area, two feet beside the patient on blood agar plates, which were incubated at 37°C for 48 h and total colony forming units (CFUs) were counted.

Results

A significant reduction in the total CFUs' counts was observed at all the three sites sampled in test groups (chlorhexidine group and herbal formulation group) as compared to control (P < 0.01).

Conclusion

The addition of antiseptic agents to the water source contributed to a significant reduction of the cultivable microbial counts in the aerosol and hence can be used to reduce the risk of cross-infection during ultrasonic scaling.

Evaluation of thin-layered agar for Mycobacterium tuberculosis isolation and drug susceptibility testing

Background

Tuberculosis (TB) is India's major public health problem. According to the WHO, India harbors the largest number of cases, and TB control remains a challenge in diagnosis, drug resistance, and treatment. We undertook this study to compare the isolation rates of Mycobacterium tuberculosis (MTB) in agar, egg-based media, incidence of multidrug-resistant (MDR), and extended drug resistance (XDR) in MTB. This study aimed to compare and evaluate thin-layered agar (TLA) for the cultivation and drug susceptibility pattern of MTB with the conventional egg-based Lowenstein-Jensen's (LJ) medium and to differentiate atypical Mycobacterium by incorporating para-nitrobenzoic acid (PNB) in the TLA medium. This cross-sectional study was conducted in Sri Ramachandra Medical College and Research Institute, Porur, Chennai.

Methods

A total of 68 smear-positive samples were inoculated into TLA (Middle Brook 7H 11) and LJ media with and without antibiotics (rifampicin, isoniazid, and ofloxacin) simultaneously after decontamination by the modified Petroff's method. TLA with PNB was also used to differentiate the growth of nontuberculous mycobacterium (NTM). Incubation was done at 37°C, and reading was taken every 3^rd day for 6 weeks in case of TLA and for 8 weeks in case of LJ medium.

Results

Out of the 68 samples, 64 (94.1%) grew in LJ, and the growth observed at the end of the 1^st, 2^nd, 3^rd, 4^th, 5^th, and 6-10^th weeks was 0, 12 (18.8%), 10 (15.6%), 14 (21.9%), 15 (23.4%), and 13 (20.3%), respectively. Similarly, in TLA, 65 (95.5%) samples were grown, among which 22 (33.8%) grew in the 1^st week and the rest (43 [66.2%]) in the 2^nd week. MDR and XDR were observed in 4 (5.8%) and 3 (4.4%) samples, respectively. Seven of them were NTM.

Conclusions

TLA is a better medium, with time to positivity ranging from 1 to 2 weeks with drug susceptibility and the pattern is also comparable with LJ medium. Incorporation of PNB in TLA helps in differentiating NTM.

Salmonella typhi Splenic Abscess Following Blunt Abdominal Injury: A Case Report

Splenic abscess as a complication of enteric fever due to Salmonella typhi is a rare entity. Here, we are presenting a case of splenic abscess caused by Salmonella typhi with a blunt injury to the abdomen as the predisposing factor. The patient underwent total splenectomy due to failure of conservative management. Splenic abscess is a potential life threatening disease if left untreated. In spite of its rarity, Salmonella typhi has to be considered as a possible pathogen causing the disease.

Carriage of Multidrug Resistant Bacteria on Frequently Contacted Surfaces and Hands of Health Care Workers

INTRODUCTION

Maximal contact between the patients and Health Care Workers (HCWs) happens in the Intensive Care Units (ICU). Control of nosocomial infections requires compliance with hand hygiene and contamination free surfaces.

AIM

To determine the colonization of potential pathogens in the hands of HCWs and frequent contacted environmental surfaces.

MATERIALS AND METHODS

A cross sectional study was conducted between September 2012 and May 2013 at Sri Ramachandra Medical College and Hospital. A total of 327 samples were collected using Glove juice technique from hands and swabs from frequently contacted surfaces. A sum of 157 samples were collected by glove juice technique from the hands of HCWs which included Consultants (20), Internees (3), Residents (10), Staff nurse (102) and support staff (22). A total of 170 samples were collected through swabbing which included frequently touched surfaces of apron and dress (140 which included 10 consultants, 3 internees, 9 Residents, 101 Staff nurse and 17 support staff), 9 door handle, 4 key board, 12 tap handles and 5 monitors. The samples were inoculated into Blood agar, Chocolate agar and Mac-Conkey agar plates and incubated at 37(0)C aerobically. The plates showing growth were further processed to identify the organisms by Gram staining and biochemical reactions. Antibiotic susceptibility testing was done for the isolates by Kirby-baur disc diffusion method as per CLSI guidelines.

RESULTS

Out of the 157 hand sampling done by glove juice method 67(42.7%) of them showed growth and 90(57.3%) showed no growth. The potential pathogens grown were 13 (8.3%), consisting of Methicillin Sensitive Staphylococcus aureus (MSSA) 6(3.8%), Methicillin Resistant Staphylococcus aureus (MRSA) 2(1.3%), Pseudomonas spp 4(2.6%) and Acenitobacter spp 1 (0.6%). The MRSA was seen in Consultant 1(5%; n=20) and Staff nurse 1(0.9%; n= 102). Among the 140 sampling from the dress of HCWs growth was observed in 69(49.3%) and growth was absent in 71(50.7%). The potential pathogens observed were 14(10%) and they are MSSA 5(3.6%), MRSA 1 (0.7%), Pseudomonas spp 2(1.4%), Acenitobacter spp 3(2.1%) Enterobacter spp 1(0.7%), Klebseilla pneumoniae 1(0.7%) and Candida spp 1(0.7%). One MRSA was isolated from staff nurse (0.9%; n=101). Similarly multi-drug resistant Klebsiella pneumoniae 1(0.9%; n=102). Out of the 30 environmental samples 16(53.3%) showed growth and in 14(56.7%) growth was absent. The potential pathogens isolated were 3(10%) which included MSSA 2(6.6%) and MRSA 1(3.4%) and were isolated from the monitor.

CONCLUSION

Adherence to infection control practices among all categories of HCWs is must for control of HAI. Glove juice method is a simple, easy and practical technique for determination of colonization of hands of HCWs and can be adapted as a methodology for screening the hands of HCWs.

Screening for Mupirocin Resistance in Staphylococcus

INTRODUCTION

Mupirocin is widely used topical antibiotic for the treatment of skin and soft tissue infections caused by Staphylococcus and Streptococcus. In addition nasal formulations are approved for the use in nasal eradication of methicillin-resistant Staphylococcus aureus in patients and health care workers. Wide usage of mupirocin has resulted in resistance leading to treatment failure.

AIM

To screen for the mupirocin resistance among the Staphylococcus isolates using disc diffusion and minimum inhibitory concentration method.

MATERIALS AND METHODS

A cross-sectional study was done at Microbiology Department of Sri Ramachandra University with 100 strains of Staphylococcus spp isolated from skin and soft tissue infections. Methicillin susceptibility was done by disc diffusion method using oxacillin (1 μgm) and cefoxitin (30 μgm) discs. Isolates were screened for mupirocin resistance by disc diffusion method using 5 μgm discs. High level and low level resistance determined by MIC using agar dilution method.

RESULTS

In 100 Staphylococcus spp 56 were Staphylococcus aureus and 44 were CoNS. Among the 56 Staphylococcus aureus 49 (87.5%) were mupirocin susceptible and 7 (12.5%) resistant by 5μg disc diffusion method. However by MIC method 11 (19.6%) were high and low level mupirocin resistant. Out of 44 CoNS 22 (50%) and 18 (41%) were susceptible by disc diffusion and MIC method respectively. Of the 26 resistant CoNS low level and high level mupirocin resistant was observed in 7 (15.9%) and 19 (43.1%) respectively.

CONCLUSION

Screening for mupirocin resistance by disc diffusion method is important before attempting decolonisation. Mupirocin resistance is more with CoNS. Disc diffusion method may miss low level Mupirocin resistance.