Neonatal Pathogen Research Articles

Prepartum Vaccination Against Neonatal Calf Diarrhea and Its Effect on Mammary Health and Milk Yield of Dairy Cows: A Retrospective Study Addressing Non-Specific Effects of Vaccination

Prepartum vaccinations against neonatal calf diarrhea pathogens are administered in late pregnancy to provide passive immunity to calves through protective colostral antibodies. Potential non-specific effects of the vaccine on maternal innate immune responses and disease susceptibility during the sensitive transition period have not been addressed so far. In this retrospective study, data from 73,378 dairy cows on 20 farms in Germany were analyzed, using linear mixed-effects regression, quantile regression, and decision-tree-algorithms, to investigate the effects of prepartum vaccination on mammary health and milk yield by comparing non-vaccinated and vaccinated transition periods. Herd management-related factors were found to be most influential for mammary health and milk yield. Vaccinated cows were not significantly more likely to develop mastitis and did not have significantly different somatic cell counts and milk yields compared to non-vaccinated cows. Healthy primiparous cows with and without vaccination had similar energy-corrected milk yields. The study concludes that prepartum vaccination against calf diarrhea has no significant effects on mammary health and milk yield. Further research is recommended to investigate potential non-specific vaccine effects on other organ systems, infectious diseases, and production metrics of the dairy cow.

Bacterial profile and antimicrobial susceptibility patterns of common neonatal sepsis pathogens in Gulf Cooperation Council countries: A systematic review and meta-analysis.

Neonatal sepsis (NS) is a major healthcare burden in Gulf Cooperation Council (GCC) countries, with a prevalence higher than the global average. Microbial drug resistance has major implications for mortality and morbidity from NS. To synthesize data regarding the patterns of causative bacteria of NS in the GCC and their antimicrobial susceptibility profiles. Following the exploration of four electronic databases, i.e., EBSCOhost, ProQuest, PubMed/MEDLINE, and ScienceDirect, eligible studies were identified (i.e., published between 2013 and 2023 and reported bacterial profile and/or antimicrobial susceptibility patterns). The outcomes included the pooled prevalence of bacteria and their susceptibility patterns. Proportion meta-analysis was performed for each outcome of interest. Fifteen studies were eligible (total positive cases = 2,473). Coagulase-negative Staphylococci (CoNS) (28.1%) were the most common gram-positive causative pathogen, followed by group B Streptococcus (GBS) (16.2%) and Staphylococcus aureus (9.9%); for gram-negative, Escherichia coli (12.7%) and Klebsiella species (11.4%) were most common. The susceptibility rates of these bacteria to first-line antibiotics were high; gram-positive bacteria had the highest susceptibility to ampicillin (72.8-98%), and gram-negative bacteria was most susceptible to amikacin (94.6-98%). Additionally, both gram-positive (67-77%) and negative (87-93%) bacteria exhibited high susceptibility to gentamicin. The most common pathogens among NS patients were gram-positive. The pathogens, irrespective of stain test, were susceptible to the current antibiotic therapy. We recommend the judicious use of empirical antibiotic therapy to prevent the growing risk of antimicrobial resistance.

Prevalence and Antibiotic Resistance Patterns of Neonatal Bloodstream Pathogens in Tertiary Care Hospitals: A Retrospective Analysis

Background: Neonatal bloodstream infections (BSIs) are a leading cause of mortality in developing countries, necessitating effective treatment strategies. Objective: This retrospective study investigated the prevalence and antibiotic susceptibility patterns of bacterial pathogens causing neonatal BSIs in two tertiary hospitals in Dhaka, Bangladesh. Methodology: This is a retrospective study took place in Ad-din Women’s Medical College & Hospital, Dhaka & Rushmono specialized Hospital, Dhaka, Bangladesh in between the time period of July 2019 to December 2020. A total of 1825 blood samples were obtained from patients who were admitted at the Neonatal Intensive care unit of Ad-din Women’s Medical College & Hospital, Dhaka & Rushmono specialized Hospital, Dhaka, Bangladesh from July 2019 to December 2020. All the blood samples were processed for culture using a BACT/Alert blood culture machine. Further identification & antimicrobial susceptibility tests were performed using standard microbiological procedure. Results: The analysis of 1825 blood samples obtained from neonatal intensive care facilities unveiled a bloodstream infection (BSI) rate of 17.2%. The predominant isolates identified were coagulase-negative Staphylococci (CONS) (10%) and Acinetobacter spp. (60%); these organisms are classified as Gram-positive and negative bacteria, respectively. The preponderance of infections was caused by Gram-positive organisms, specifically CONS, which evolved highly sensitive to imepenem, vancomycin, and linezolid but resistance to ampicillin, cephradine and erythromycin. Methicillin resistance is present in 31.5% of Staphylococcus aureus and nearly half (47%) of the CONS. Vancomycin resistance is present in one-tenth of the isolated Staphylococcus species. Acinetobacter spp. exhibited greater susceptibility to colistin (100%), meropenem (90.67%), piperacillin-tazobactum (92%), and amikacin (82.67%), but resistance to ampicillin (90%), cephradin (80%), cefuroxime (90%), and cefixime (61%). Proteus, Enterobacterieceae, including E. coli, Klebsiella, and Enterobacter, exhibited greater resistance to ampicillin, cephradin, and chloramphenicol while demonstrating greater sensitivity to meropenem (100%), piperacillin-tazobactum (95-98%), amikacin (80-82%), and gentamycin (76%-80%). Conclusion: Major causative agents of neonatal blood stream infection were coagulase-negative Staphylococci (CONS) and Acinetobacter spp. Multidrug resistance among these bacteria was observed in the study ; which necessitate the implementation of antibiotic stewardship program to improve neonatal outcome. Bangladesh Journal of Medical Microbiology, January 2024;18(1):22-29

Regulators of placental antibody transfer through a modeling lens.

Infants are vulnerable to infections owing to a limited ability to mount a humoral immune response and their tolerogenic immune phenotype, which has impeded the success of newborn vaccination. Transplacental transfer of IgG from mother to fetus provides crucial protection in the first weeks of life, and maternal immunization has recently been implemented as a public health strategy to protect newborns against serious infections. Despite their early success, current maternal vaccines do not provide comparable protection across pregnancies with varying gestational lengths and placental and maternal immune features, and they do not account for the dynamic interplay between the maternal immune response and placental transfer. Moreover, progress toward the rational design of maternal vaccines has been hindered by inadequacies of existing experimental models and safety challenges of investigating longitudinal dynamics of IgG transfer in pregnant humans. Alternatively, in silico mechanistic models are a logical framework to disentangle the processes regulating placental antibody transfer. This Review synthesizes current literature through a mechanistic modeling lens to identify placental and maternal regulators of antibody transfer, their clinical covariates, and knowledge gaps to guide future research. We also describe opportunities to use integrated modeling and experimental approaches toward the rational design of vaccines against existing and emerging neonatal pathogen threats.

ESKAPE pathogens in pediatric cardiac surgery patients: 5-year microbiological monitoring inatertiary hospital in Kazakhstan.

Hospital acquired infections greatly affect recovery and survival in pediatric surgical patients. We evaluated prevalence and antimicrobial resistance of ESKAPE pathogens in neonates and infants subjected to cardiac surgery in a tertiary hospital in Central Kazakhstan between 2019 and 2023 (2,278 patients) using routine methods of microbiological detection. ESKAPE pathogens were found in 1,899 out of 2,957 samples (Staphylococcus aureus - 35.3%, Klebsiella pneumoniae - 27.8%, Acinetobacter baumannii - 14.5%, Pseudomonas aeruginosa - 12.4%, Enterobacter sp. - 8.8%, Enterococcus faecium - 1.2%). The total prevalence of ESKAPE increased significantly from 45.1 to 76.9% (P = 0.005) during the study period. The resistance significantly increased in methicillin-resistant S. aureus (MRSA, from13.7 to 41.9%, P = 0.041) but decreased in carbapenem-resistant P. aeruginosa (from 64.3 to 37.7%, P = 0.037) and carbapenem-resistant A. baumannii (from 48.5 to 19.1%, P = 0.039). Gradual but non-significant changes were shown in third-generation cephalosporin resistant K. pneumoniae (from 63.6 to 45.2%) and carbapenem-resistant K. pneumoniae (from 0 to 8.3%). The relative prevalence of ESKAPE pathogens steadily increased in our pediatric cardiac surgery patients in 2019-2023. The most frequent were S. aureus, K. pneumoniae, and A. baumannii, with dramatically increasing tendencies for MRSA. Our results highlight the necessity for a well-designed infection control strategy and constant microbiological monitoring in pediatric cardiac surgery departments.

Acinetobacter spp. in neonatal sepsis: an urgent global threat

Neonatal sepsis causes substantial morbidity and mortality, the burden of which is carried by low-income countries (LICs). The emergence of multidrug-resistant pathogens in vulnerable neonatal populations poses an urgent threat to infant survival. Acinetobacter spp. are increasingly responsible for severe disease in neonates globally. The cause of this escalation remains unclear, but host, pathogen and environmental factors are all likely to contribute. Acinetobacter spp. strains are frequently resistant to the first line empirical treatment for neonatal sepsis as recommended by the World Health Organization (WHO), ampicillin and gentamicin, rendering these antibiotics ineffectual in many critically ill neonates. The resultant escalation to broader spectrum antibiotic regimens in neonatal intensive care units (NICUs) worldwide has led to the emergence of more resistant strains, including carbapenem-resistant Acinetobacter baumanii (CRAB), resulting in infections that are ever more difficult to treat. While some existing antimicrobial agents are under consideration for treatment of Acinetobacter spp. infections, the majority remain a long way from clinical use in neonates. Further research into the clinical phenotype of these infections, transmission dynamics and preventative measures are urgently needed to reduce neonatal deaths. This review aims to summarise the role of Acinetobacter spp. in neonatal sepsis, including host, pathogen and environmental factors, the global epidemiology and clinical features of the disease, the treatment options, and future research priorities.

Predictive factors for perinatal bacterial transmission from colonized mothers to delivered very-low-birth-weight infants: a retrospective cohort study

This study investigated the predictive factors for perinatal bacterial transmission in very-low-birth-weight infants (VLBWIs) born to mothers with a history of intrapartum colonization. We retrospectively reviewed the medical records of 173 VLBWIs, wherein pathogens were confirmed in maternal cultures obtained from the blood, urine, and vagina during the intrapartum period from 2013 to 2020. Newborns were categorized based on microbiological tests, including gastric aspirates, endotracheal aspirates, blood, and skin/nasal swab cultures collected immediately after birth. Infants whose cultures matched their maternal pathogens were categorized into the “transmission group” (n = 45), while those who tested negative were assigned to the “control group” (n = 128). The predominant maternal-colonizing pathogen observed was Escherichia coli (30.6%), which also emerged as the primary colonizing pathogen in neonates (35.6%). Transmission group had higher incidences of maternal leukocytosis, chorioamnionitis, and cervical cerclage. Regarding neonatal characteristics, the transmission group demonstrated lower initial base excesses (− 6.3 ± 3.9 vs. − 9.2 ± 4.9, P < 0.05) and higher C-reactive protein levels (0.1 ± 0.3 vs. 0.4 ± 0.8, P < 0.05). Notably, regarding major neonatal outcomes, transmission group had higher mortality rates and incidences of severe intraventricular hemorrhage. These findings may be useful for making decisions when considering antibiotic treatment for infants with a history of maternal colonization.

Investigating the antimicrobial potential of bovine lactoferrin against the neonatal pathogen, Staphylococcus capitis.

Lactoferrin is an antimicrobial glycoprotein that demonstrates a broad-spectrum of activity against a wide variety of clinical pathogens. This study investigated the potential of bovine lactoferrin (bLf) against multidrug resistant Staphylococcus capitis (S. capitis) strains. Growth curve analysis and time-kill curves demonstrated that at 750µg ml-1 lactoferrin significantly inhibited (50.6%, P<0.05) the growth of most isolates tested (90%), and this effect was based on a bacteriostatic mechanism. At the same concentration, bLf also significantly inhibited (30%, P<0.05) biofilm formation in 40% of strains tested. Combinations of bLf with selected antibiotics were assessed for enhanced antimicrobial activity using growth curves. BLf combined with β-lactam antibiotics reduced the growth of S. capitis strains, however, the effects were not significant. BLf displays antimicrobial effects against multidrug resistant S. capitis isolates, but with strain-specific effects.

Human Milk Protein-Derived Bioactive Peptides from In Vitro-Digested Colostrum Exert Antimicrobial Activities against Common Neonatal Pathogens.

Human milk reduces risk for necrotizing enterocolitis in preterm infants. Necrotizing enterocolitis occurs in the ileocecal region where thousands of milk protein-derived peptides have been released from digestion. Digestion-released peptides may exert bioactivity, such as antimicrobial and immunomodulatory activities, in the gut. In this study, we applied mass spectrometry-based peptidomics to characterize peptides present in colostrum before and after in vitro digestion. Sequence-based computational modeling was applied to predict peptides with antimicrobial activity. We identified more peptides in undigested samples, yet the abundances were much higher in the digested samples. Heatmapping demonstrated highly different peptide profiles between undigested and digested samples. Four peptides (αS1-casein [157-163], αS1-casein [157-165], β-casein [153-159] and plasminogen [591-597]) were selected, synthesized and tested against common pathogenic bacteria associated with necrotizing enterocolitis. All four exhibited bacteriostatic, though not bactericidal, activities against Klebsiella aerogenes, Citrobacter freundii and Serratia marcescens, but not Escherichia coli.

Preterm infant with necrotizing enterocolitis and arteritis secondary to streptococcus gallolyticus subspecies pasteurianus.

Streptococcus gallolyticus subspecies pasteurianus is a subtype of Streptococcus bovis (S. bovis) that has become increasingly recognized as a sepsis-causing pathogen in neonates. It is well documented that S. bovis species have a predilection to both cardiac and gastrointestinal tissue, and in adult populations, isolating these organisms in the bloodstream often triggers further evaluation for co-morbid complications such as colon cancer or endocarditis. However, no such guidance currently exists in neonatal literature. We present a case of a preterm infant with S. gallolyticus subsp. pasteurianus bacteremia presenting as necrotizing enterocolitis (NEC) not previously described in the literature. Furthermore, through a complete diagnostic evaluation, including an echocardiogram, our patient was found to have the rare complication of endocarditis.

A dual-channel electrochemical biosensor enables concurrent detection of pathogens and antibiotic resistance

Diarrheagenic E. coli infections, commonly treated with β-lactam antibiotics, contribute to antibiotic resistance - a pressing public health concern. Rapid monitoring of pathogen antibiotic resistance is vital to combat antimicrobial spread. Current bacterial diagnosis methods identify pathogens or determine antibiotic resistance separately, necessitating multiple assays. There is an urgent need for tools that simultaneously identify infectious agents and their antibiotic resistance at the point of care (POC). We developed an integrated electrochemical chip-based biosensor for detecting enteropathogenic E. coli (EPEC), a major neonatal diarrheal pathogen, using an antibody against a virulence marker, termed EspB, and the β-lactam resistance marker, β-lactamase. A dual-channel microfabricated chip, bio-functionalized with a specific EspB monoclonal antibody, and nitrocefin, a β -lactamase substrate was utilized. The chip facilitated electrochemical impedance spectroscopy (EIS)-based detection of EspB antigen and EspB-expressing bacteria. For β-lactam resistance profiling, a second channel enabled differential-pulse voltammetric (DPV) measurement of hydrolyzed nitrocefin. EIS-based detection of EspB antigen was calibrated (LOD: 4.3 ng/mL ±1 and LOQ: 13.0 ng/mL ±3) as well as DPV-based detection of the antibiotic resistance marker, β-lactamase (LOD: 3.6 ng/mL ±1.65 and LOQ: 10 ng/mL ±4). The integrated EIS and DPV biosensor was employed for the simultaneous detection of EspB-expressing and β-lactamase-producing bacteria. The combined readout from both channels allowed the distinction between antibiotic-resistant and -sensitive pathogenic bacteria. The integrated electrochemical biosensor successfully achieved simultaneous, rapid detection of double positive EspB- and β-lactamase-expressing bacteria. Such distinction enabled by a portable device within a short assay time and a simplified sample preparation, may be highly valuable in mitigating the spread of AMR. This new diagnostic tool holds promise for the development of POC devices in clinical diagnosis.

Engagement of α3β1 and α2β1 integrins by hypervirulent Streptococcus agalactiae in invasion of polarized enterocytes.

The gut represents an important site of colonization of the commensal bacterium Streptococcus agalactiae (group B Streptococcus or GBS), which can also behave as a deadly pathogen in neonates and adults. Invasion of the intestinal epithelial barrier is likely a crucial step in the pathogenesis of neonatal infections caused by GBS belonging to clonal complex 17 (CC17). We have previously shown that the prototypical CC17 BM110 strain invades polarized enterocyte-like cells through their lateral surfaces using an endocytic pathway. By analyzing the cellular distribution of putative GBS receptors in human enterocyte-like Caco-2 cells, we find here that the alpha 3 (α3) and alpha 2 (α2) integrin subunits are selectively expressed on lateral enterocyte surfaces at equatorial and parabasal levels along the vertical axis of polarized cells, in an area corresponding to GBS entry sites. The α3β1 and α2β1 integrins were not readily accessible in fully differentiated Caco-2 monolayers but could be exposed to specific antibodies after weakening of intercellular junctions in calcium-free media. Under these conditions, anti-α3β1 and anti-α2β1 antibodies significantly reduced GBS adhesion to and invasion of enterocytes. After endocytosis, α3β1 and α2β1 integrins localized to areas of actin remodeling around GBS containing vacuoles. Taken together, these data indicate that GBS can invade enterocytes by binding to α3β1 and α2β1 integrins on the lateral membrane of polarized enterocytes, resulting in cytoskeletal remodeling and bacterial internalization. Blocking integrins might represent a viable strategy to prevent GBS invasion of gut epithelial tissues.

Metagenomic Next-generation Sequencing for Pathogen Identification in Bronchoalveolar Lavage Fluid From Neonates Receiving Extracorporeal Membrane Oxygenation.

Neonates on extracorporeal membrane oxygenation (ECMO) are at high risk of infection. Rapid and accurate identification of pathogens is essential to improve the prognosis of children on ECMO. Metagenome next-generation sequencing (mNGS) has been used in recent years to detect pathogenic bacteria, but evidence for its use in neonates on ECMO is lacking. This retrospective study was conducted using an electronic medical record system. We analyzed the results of mNGS and conventional microbiological tests (CMTs) in bronchoalveolar lavage fluid of neonates receiving ECMO support with pulmonary infections in our hospital from July 2021 to January 2023. We screened 18 ECMO-supported neonates with pneumonia for inclusion in the study. The median age of the included children was 2 (1-4) days, the median gestational age was 38.3 (33-40 +4 ) weeks, and the median weight was 3.3 (2.2-4.8) kg. The detection rate of mNGS was 77.8% (14/18), higher than the 44.4% (8/18) of CMT ( P = 0.04). A total of 20 pathogens were detected in mNGS, with the top 3 most common pathogens being Klebsiella pneumoniae , Acinetobacter baumannii and Escherichia coli . Mixed infections were found in 14 cases (77.8%), including 13 cases (72.2%) with mixed infections detected by mNGS and 7 cases (27.8%) with mixed infections detected by CMT. A total of 9 children underwent treatment changes based on mNGS results and all of them experienced relief of symptoms. Compared with CMT, mNGS can detect pathogens earlier and more sensitively, and may play an important role in ECMO-supported neonatal pneumonia pathogen detection and optimization of antibiotic therapy.

INTERRELATIONSHIP BETWEEN INDICATORS OF LOCAL AND SYSTEMIC INFLAMMATORY REACTION IN NEWBORNS WITH NEONATAL ENCEPHALOPATHY

Introduction. Neonatal encephalopathy is one of the most common diseases in newborns. Several factors influence the development of neonatal encephalopathy including adverse obstetric history, fetal distress, meconium-containing amniotic fluid and cesarean section. In moderate and severe neonatal encephalopathy, damage to internal organs, local and systemic inflammation may occur. Cytokines, which are activated in the central nervous system and released in response to its damage, play an important role in brain inflammation caused by neonatal encephalopathy. C-reactive protein is also a possible biomarker of neonatal encephalopathy severity, being considered a protein of the innate immune system with anti-inflammatory properties. The state of the inflammatory response can be influenced by a local inflammatory reaction, as a result of which children with neonatal encephalopathy have been shown to have increased levels of fecal calprotectin in the first weeks of life. Also, one of the results of the transferred inflammatory reaction is a change in the composition of the neonatal intestinal microbiome. Objective. To study risk factors for neonatal encephalopathy in newborns, the features of the relationship between local and systemic inflammatory response parameters in asphyxia of varying degrees, and the features of severity and control of inflammatory response parameters. Materials and methods. The study was conducted in 119 full-term newborns, of which 87 children had neonatal encephalopathy and 32 healthy children. To determine the features of severity and control of inflammatory response parameters, group A was identified, which included 60 newborns, 46 of them with moderate neonatal encephalopathy, 14 with severe neonatal encephalopathy. The study was conducted using a culture method to determine the composition of the intestinal microbiome in feces. Using a semi-automated Thermo Scientific Multiskan FC enzyme immunoassay analyzer, the level of fecal calprotectin in feces and C-reactive protein and interleukins 1β and 10 in the blood serum were estimated by the enzyme immunoassay. The results were analyzed using SPSS version 28.0. The correlation between the parameters was analyzed using the Pearson correlation coefficient. The odds ratio was used to quantitatively describe the closeness of the relationship between the features in the statistical population. Binary logistic regression was used to determine the dependencies of the severity of the inflammatory reaction and create a model for calculating its severity. Results. Risk factors for neonatal encephalopathy included mother’s acute respiratory infections and fetal distress. Bifidobacterium levels were positively correlated throughout the study, and there was also a relationship with lactobacilli in the control and non-probiotic treated neonatal encephalopathy groups. E. coli values were positively associated with opportunistic pathogens in the control and probiotic treated groups. Fecal calprotectin was negatively correlated with birth weight and height, Apgar scores, and gestational age. Fecal calprotectin levels were positively correlated with E. coli and opportunistic pathogens in healthy neonates. In children with neonatal encephalopathy interleukin 1β and 10 values were positively associated with fecal calprotectin, interleukin 1β were positively correlated with interleukin 10 and C-reactive protein. Conclusions. The most significant risk factors for the development of neonatal encephalopathy are mother’s acute infectious diseases and fetal distress. The severity of hypoxia/asphyxia at birth correlated with the levels of interleukin 1β and 10 at 2 and 5 weeks of life, and Bifidobacterium at 2 weeks of life. The severity of the inflammatory response in the study population was characterized by a change in the level of interleukin 1β and Bifidobacterium at 2 weeks and a change in the level of interleukin 10 at 5 weeks

World Health Organization Danger Signs to predict bacterial sepsis in young infants: A pragmatic cohort study.

Bacterial sepsis is generally a major concern in ill infants. To help triaging decisions by front-line health workers in these situations, the World Health Organization (WHO) has developed danger signs (DS). The objective of this study was to evaluate the extent to which nine DS predict bacterial sepsis in young infants presenting with suspected sepsis in a low-income country setting. The study pragmatically evaluated nine DS in infants younger than 3 months with suspected sepsis in a regional hospital in Lilongwe, Malawi, between June 2018 and April 2020. Main outcomes were positive blood or cerebrospinal fluid (CSF) cultures for neonatal pathogens, and mortality. Among 401 infants (gestational age [mean ± SD]: 37.1±3.3 weeks, birth weight 2865±785 grams), 41 had positive blood or CSF cultures for a neonatal pathogen. In-hospital mortality occurred in 9.7% of infants overall (N = 39/401), of which 61.5% (24/39) occurred within 48 hours of admission. Mortality was higher in infants with bacterial sepsis compared to other infants (22.0% [9/41] versus 8.3% [30/360]; p = 0.005). All DS were associated with mortality except for temperature instability and tachypnea, whereas none of the DS were significantly associated with bacterial sepsis, except for "unable to feed" (OR 2.25; 95%CI: 1.17-4.44; p = 0.017). The number of DS predicted mortality (OR: 1.75; 95%CI: 1.43-2.17; p<0.001; AUC: 0.756), but was marginally associated with positive cultures with a neonatal pathogen (OR 1.22; 95%CI: 1.00-1.49; p = 0.046; AUC: 0.743). The association between number of DS and mortality remained significant after adjusting for admission weight, the only statistically significant co-variable (OR 1.75 [95% CI: 1.39-2.23]; p<0.001). Considering all positive cultures including potential bacterial contaminants resulted a non-significant association between number of DS and sepsis (OR 1.09 [95% CI: 0.93-1.28]; p = 0.273). In conclusion, this study shows that DS were strongly associated with death, but were marginally associated with culture-positive pathogen sepsis in a regional hospital setting. These data imply that the incidence of bacterial sepsis and attributable mortality in infants in LMIC settings may be inaccurately estimated based on clinical signs alone.

Antibiotic Use for Sepsis in Hospitalized Neonates in Botswana: Factors Associated with Guideline-Divergent Prescribing.

In low- and middle-income countries, where antimicrobial access may be erratic and neonatal sepsis pathogens are frequently multidrug-resistant, empiric antibiotic prescribing practices may diverge from the World Health Organization (WHO) guidelines. This study examined antibiotic prescribing for neonatal sepsis at a tertiary referral hospital neonatal unit in Gaborone, Botswana, using data from a prospective cohort of 467 neonates. We reviewed antibiotic prescriptions for the first episode of suspected sepsis, categorized as early-onset (EOS, days 0-3) or late-onset (LOS, >3 days). The WHO prescribing guidelines were used to determine whether antibiotics were "guideline-synchronous" or "guideline-divergent". Logistic regression models examined independent associations between the time of neonatal sepsis onset and estimated gestational age (EGA) with guideline-divergent antibiotic use. The majority (325/470, 69%) were prescribed one or more antibiotics, and 31 (10%) received guideline-divergent antibiotics. Risk factors for guideline-divergent prescribing included neonates with LOS, compared to EOS (aOR [95% CI]: 4.89 (1.81, 12.57)). Prematurity was a risk factor for guideline-divergent prescribing. Every 1-week decrease in EGA resulted in 11% increased odds of guideline-divergent antibiotics (OR [95% CI]: 0.89 (0.81, 0.97)). Premature infants with LOS had higher odds of guideline-divergent prescribing. Studies are needed to define the causes of this differential rate of guideline-divergent prescribing to guide future interventions.

Application of Next-Generation Sequencing to Enterobacter Hormaechei Subspecies Analysis during a Neonatal Intensive Care Unit Outbreak.

The Enterobacter cloacae complex (ECC) species are potential neonatal pathogens, and ECC strains are among the most commonly encountered Enterobacter spp. associated with nosocomial bloodstream infections. Outbreaks caused by ECC can lead to significant morbidity and mortality in susceptible neonates. At the molecular level, ECC exhibits genomic heterogeneity, with six closely related species and subspecies. Genetic variability poses a challenge in accurately identifying outbreaks by determining the clonality of ECC isolates. This difficulty is further compounded by the limitations of the commonly used molecular typing methods, such as pulsed field gel electrophoresis, which do not provide reliable accuracy in distinguishing between ECC strains and can lead to incorrect conclusions. Next-generation sequencing (NGS) offers superior resolution in determining strain relatedness. Therefore, we investigated the clinical pertinence of incorporating NGS into existing bundle measures to enhance patient management during an outbreak of ECC in a level-3 neonatal intensive care unit (NICU) in Germany. As the standard of care, all neonates on the NICU received weekly microbiological swabs (nasopharyngeal and rectal) and analysis of endotracheal secretion, where feasible. During the 2.5-month outbreak, colonisation with ECC was detected in n = 10 neonates. The phylogenetic relationship and potential antimicrobial resistance genes as well as mobile genetic elements were identified via bacterial whole-genome sequencing (WGS) using Illumina MiSeq followed by in silico data analysis. Although all ECC isolates exhibited almost identical antimicrobial susceptibility patterns, the WGS data revealed the involvement of four different ECC clones. The isolates could be characterised as Enterobacter hormaechei subspecies steigerwaltii (n = 6, clonal), subsp. hoffmannii (n = 3, two clones) and subsp. oharae (n = 1). Despite the collection of environmental samples, no source of this diffuse outbreak could be identified. A new standardised operating procedure was implemented to enhance the management of neonates colonised with MRGN. This collaborative approach involved both parents and medical professionals and successfully prevented further transmission of ECC. Initially, it was believed that the NICU outbreak was caused by a single ECC clone due to the similarity in antibiotic resistance. However, our findings show that antibiotic susceptibility patterns can be misleading in investigating outbreaks of multi-drug-resistant ECC. In contrast, bacterial WGS accurately identified ECC at the clonal level, which significantly helped to delineate the nature of the observed outbreak.

The changing profile of neonatal pathogens and susceptibility pattern: prospective observational study from a tertiary center in South India

Introduction: Changing the pattern of neonatal pathogens poses challenges to the management of neonatal sepsis. Profile and antimicrobial susceptibility of neonatal pathogens were evaluated in this prospective observational study in a tertiary center. Methods: Neonates with risk factors and clinical features of sepsis were screened. Blood culture performed in positive-screen babies. Antimicrobial susceptibility was also evaluated. Statistical significance was tested by the chi-square test and t test accordingly. Univariate analysis was performed to study possible correlations in this regard. Results: Out of 431 suspected cases, 89 neonates (20.65%) had sepsis. The rate of early and late-onset sepsis (LOS) was 48.3% and 51.7%, respectively. The clinical spectrum included septicemia 68 (76.5%), congenital pneumonia 13 (14.7%), meningitis 5 (5.7%), and septic arthritis 3 (3.4%), respectively. Gram-positive bacteria constituted 61 (68.5%), while gram-negative was 28 (31.5%) (P&lt;0.05). Staphylococcus aureus (23.6%) and methicillin-resistant S. aureus (MRSA) (22.5%) were the most common isolates. Acinetobacter (15.8%), coagulase-negative staphylococcus areus (CoNS) (11%), Klebsiella (7.9%), enterococci (8%), E. coli (4.5%), and ß hemolytic streptococci (1 case) were other detected pathogens. MRSA, Acinetobacter, and coagulase-negative S. aureus as a single entity involved in sepsis pathogenesis (50.6%) showed a positive correlation with inborn babies, pre-term, low birth weight, and early-onset sepsis (OR; 95% CI: 2.20; 0.94–5.20, 1.82; 0.79–4.22, 1.25; 0.55–2.89 and 1.05; 0.46–2.50 respectively). Susceptibility pattern was penicillin (12.3%), ampicillin (6.7%), cloxacillin (42.9%), cefotaxime (8%), cefazolin (37.9%), cefoperazone sulbactam (81.5%), piperacillin-tazobactam (68.9%), gentamicin (63.5%), amikacin (47.9%), vancomycin (88.9%), linezolid (88.6%), co-trimoxazole (55.4%), and clindamycin (50%). Conclusion: Gram-positive pathogens and opportunistic pathogens like Acinetobacter predominate over the conventional gram-negative pathogens in neonates. Of note, penicillin, ampicillin, and cefotaxime are not suitable for the empiric treatment of neonatal sepsis.

A Narrative Review of Staphylococcus hominis Resistance Pattern: Multidrug- and Possible Extensively Drug-Resistance

Staphylococcus hominis is the third most frequent opportunistic pathogen in neonates and immunosuppressed patients that cause bacteremia, septicemia, endophthalmitis, and endocarditis. The emergence of methicillin resistant Staphylococcus hominis (MRSHo) has been reported and is a growing concern. This review was intended to determine the susceptibility of Staphylococcus hominis to antibiotic agents with pharmacokinetics/pharmacodynamic approach. In addition, this review was determined the phenotypic criteria and antibiotic choice of Staphylococcus hominis infection. Four databases i.e., PubMed, PlosOne, ScienceDirect and Google Scholar were employed in searching process. Antibiotic resistance was identified using the minimum inhibitory concentration (MIC) and the percentage of resistance. The breakpoint value was based on The European Committee on Antimicrobial Susceptibility Testing (EUCAST) Breakpoint tables for interpretation of MIC and zone diameters Version 11.0. There were 876 articles identified, 35 duplications were removed. These gave a total of 841 articles were screened yet 820 articles were irrelevant. Eventually, 21 articles were reviewed in this report. This review found that Staphylococcus hominis is potentially had MDR activity and a possible XDR bacterium that resistant to some antibacterial agents. The susceptibility of antibiotic to bacteria is not identical, and the regional reported drug resistance varies commonly due to differences in environment and antibiotic use. The resistance profile of Staphylococcus hominis is a complex interaction that affected by multifactorial such as: pharmacokinetics/pharmacodynamics index, mutant prevention concentration (MPC), mutant selection window (MSW), and the capability to produce biofilm.

High-Pressure Processing of Human Milk: A Balance between Microbial Inactivation and Bioactive Protein Preservation

BackgroundDonor human milk banks use Holder pasteurization (HoP; 62.5°C, 30 min) to reduce pathogens in donor human milk, but this process damages some bioactive milk proteins. ObjectivesWe aimed to determine minimal parameters for high-pressure processing (HPP) to achieve >5-log reductions of relevant bacteria in human milk and how these parameters affect an array of bioactive proteins. MethodsPooled raw human milk inoculated with relevant pathogens (Enterococcus faecium, Staphylococcus aureus, Listeria monocytogenes, Cronobacter sakazakii) or microbial quality indicators (Bacillus subtilis and Paenibacillus spp. spores) at 7 log CFU/mL was processed at 300–500 MPa at 16–19°C (due to adiabatic heating) for 1–9 min. Surviving microbes were enumerated using standard plate counting methods. For raw milk, and HPP-treated and HoP-treated milk, the immunoreactivity of an array of bioactive proteins was assessed via ELISA and the activity of bile salt-stimulated lipase (BSSL) was determined via a colorimetric substrate assay. ResultsTreatment at 500 MPa for 9 min resulted in >5-log reductions of all vegetative bacteria, but <1-log reduction in B. subtilis and Paenibacillus spores. HoP decreased immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G, lactoferrin, elastase and polymeric immunoglobulin receptor (PIGR) concentrations, and BSSL activity. The treatment at 500 MPa for 9 min preserved more IgA, IgM, elastase, lactoferrin, PIGR, and BSSL than HoP. HoP and HPP treatments up to 500 MPa for 9 min caused no losses in osteopontin, lysozyme, α-lactalbumin and vascular endothelial growth factor. ConclusionCompared with HoP, HPP at 500 MPa for 9 min provides >5-log reduction of tested vegetative neonatal pathogens with improved retention of IgA, IgM, lactoferrin, elastase, PIGR, and BSSL in human milk.