BackgroundThere is a paucity of data on the epidemiology of sepsis in outborn neonates being referred to level-3 units in low- and middle-income countries (LMIC). The objective of the present study was to evaluate the prevalence of sepsis and outcomes of outborn neonates with sepsis, and to characterize the pathogen profile and antimicrobial resistance (AMR) patterns of common isolates in them.MethodsIn this prospective observational cohort study (2011–2015), a dedicated research team enrolled all neonates admitted to an outborn level-3 neonatal unit and followed them until discharge/death. Sepsis work-up including blood culture(s) was performed upon suspicion of sepsis. All the isolates were identified and tested for antimicrobial susceptibility. Gram-negative pathogens resistant to any three of the five antibiotic classes (extended-spectrum cephalosporins, carbapenems, aminoglycosides, fluoroquinolones, and piperacillin-tazobactam) were labeled multi-drug resistant.ResultsOf the total of 2588 neonates enrolled, culture positive sepsis and total sepsis–i.e. culture positive and/or culture negative sepsis–was diagnosed in 13.1% (95% CI 11.8% to 14.5%) and 54.7% (95% CI 52.8% to 56.6%), respectively. The case fatality rates were 23.4% and 11.0% in culture-positive and total sepsis, respectively. Sepsis accounted for two-thirds of total neonatal deaths (153/235, 63.0%). Bacterial isolates caused about three-fourths (296/401; 73.8%) of the infections. The two common pathogens–Klebsiella pneumoniae (n = 50, 12.5%) and Acinetobacter baumannii (n = 46, 11.5%)–showed high degree of multi-drug resistance (78.0% and 91.3%, respectively) and carbapenem resistance (84.0% and 91.3%, respectively). About a quarter of infections were caused by Candida spp. (n = 91; 22.7%); almost three-fourths (73.7%) of these infections occurred in neonates born at or after 32 weeks’ gestation and about two-thirds (62.1%) in those weighing 1500 g or more at birth.ConclusionsIn this large outborn cohort, we report high burden of sepsis, high prevalence of systemic fungal infections, and alarming rates of antimicrobial resistance among bacterial pathogens.

A prospective study of the prevalent aetiology of enteric fever was undertaken at a tertiary care hospital in North India at intervals of every 3 years. Salmonella spp. were isolated from 174 (7%) patients. Amongst these, 140 (80%) patients were infected by Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) and 16 (9%) by S. enterica serovar Paratyphi A; the remaining 11% were infected by other S. enterica serogroups, Typhimurium, Paratyphi C and Senftenberg, and other group E salmonella. A significantly greater number of S. Typhi were isolated in the summer and monsoon months. Multidrug resistance (resistance to chloramphenicol, ampicillin and co-trimoxazole) sequentially increased from 34% in 1999 to 66% in 2005. Increasing resistance was also noticed to the other antibiotics, especially to the cephalosporins. Moreover 8% of the S. Typhi isolates were found to be presumptive extended spectrum beta-lactamase producers. There was a gradual development of resistance to fluoroquinolones over the 7 years. No resistance was observed to fluoroquinolones in 1999, while in 2005 4.4% resistance was observed to sparfloxacin, 8.8% resistance to ofloxacin and a high resistance, 13%, to ciprofloxacin. This is an alarming development and it is of paramount importance to limit unnecessary use of fluoroquinolones and third generation cephalosporins so that their efficacy against salmonella is not jeopardized further.

Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection in children worldwide. Sirtuin 1 (SIRT1), a NAD+ dependent deacetylase, has been associated with induction of autophagy, reprogramming cellular metabolism, and regulating immune mediators. In this study, we investigated the role of SIRT1 in bone marrow dendritic cell (BMDC) function during RSV infection. SIRT1 deficient (SIRT1-/-) BMDC showed a defect in mitochondrial membrane potential (Δ⍦m) that worsens during RSV infection. This defect in Δ⍦m caused the generation of elevated levels of reactive oxygen species (ROS). Furthermore, the oxygen consumption rate (OCR) was reduced as assessed in Seahorse assays, coupled with lower levels of ATP in SIRT1-/-DC. These altered responses corresponded to altered innate cytokine responses in the SIRT1-/-DC in response to RSV infection. Reverse Phase Protein Array (RPPA) functional proteomics analyses of SIRT1-/-and WT BMDC during RSV infection identified a range of differentially regulated proteins involved in pathways that play a critical role in mitochondrial metabolism, autophagy, oxidative and ER stress, and DNA damage. We identified an essential enzyme, acetyl CoA carboxylase (ACC1), which plays a central role in fatty acid synthesis and had significantly increased expression in SIRT1-/-DC. Blockade of ACC1 resulted in metabolic reprogramming of BMDC that ameliorated mitochondrial dysfunction and reduced pathologic innate immune cytokines in DC. The altered DC responses attenuated Th2 and Th17 immunity allowing the appropriate generation of anti-viral Th1 responses both in vitro and in vivo during RSV infection thus reducing the enhanced pathogenic responses. Together, these studies identify pathways critical for appropriate DC function and innate immunity that depend on SIRT1mediated regulation of metabolic processes.

Lower respiratory tract infections are considered a common cause responsible for morbidity and mortality among children, and Mycoplasma pneumoniae is identified to be responsible for up to 40 per cent of community-acquired pneumonia in children greater than five years of age. Extrapulmonary manifestations have been reported either due to spread of infection or autoimmune mechanisms. Infection by M. pneumoniae has high incidence and clinical importance but is still an underrated disease. Most widely used serologic methods are enzyme immunoassays for detection of immunoglobulin M (IgM), IgG and IgA antibodies to M. pneumoniae, though other methods such as particle agglutination assays and immunofluorescence methods are also used. Detection of M. pneumoniae by nucleic acid amplification techniques provides fast, sensitive and specific results. Utilization of polymerase chain reaction (PCR) has improved the diagnosis of M. pneumoniae infections. Besides PCR, other alternative amplification techniques include (i) nucleic acid sequence-based amplification, (ii) Qβ replicase amplification, (iii) strand displacement amplification, (iv) transcription-mediated amplification, and (v) ligase chain reaction. Macrolides are used as the first-line treatment in childhood for M. pneumoniae infections; however, emergence of macrolide-resistant M. pneumoniae is a cause of concern. Development of a safe vaccine is important that gives protective immunity and would be a major step in reducing M. pneumoniae infections.