Microbial Transmission Research Articles

Maternal provisioning of an obligate symbiont in a sponge.

The transmission of microbes from mother to offspring is an ancient, advantageous, and widespread feature of metazoan life history. Despite this, little is known about the quantitative strategies taken to maintain symbioses across generations. The quantity of maternal microbes that is provided to each offspring through vertical transmission could theoretically be stochastic (no trend), consistent (an optimal range is allocated), or provisioned (a trade-off with fecundity). Examples currently come from animals that release free-living eggs (oviparous) and suggest that offspring are provided a consistent quantity of symbionts. The quantity of maternal microbes that is vertically transmitted in other major reproductive strategies has yet to be assessed. We used the brooding (viviparous) sponge Halichondria panicea to test whether offspring receive quantitatively similar numbers of maternal microbes. We observed that H. panicea has a maternal pool of the obligate symbiont Candidatus Halichondribacter symbioticus and that this maternal pool is provisioned proportionally to reproductive output and allometrically by offspring size. This pattern was not observed for the total bacterial community. Experimental perturbation by antibiotics could not reduce the abundance of Ca. H. symbioticus in larvae, while the total bacterial community could be reduced without affecting the ability of larvae to undergo metamorphosis. A trade-off between offspring size and number is, by definition, maternal provisioning and parallel differences in Ca. H. symbioticus abundance would suggest that this obligate symbiont is also provisioned.

Mapping the human oral and gut fungal microbiota in patients with metabolic dysfunction-associated fatty liver disease.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a phenotype of liver diseases associated with metabolic syndrome. The pathogenesis MAFLD remains unclear. The liver maintains is located near the intestine and is physiologically interdependent with the intestine via metabolic exchange and microbial transmission, underpinning the recently proposed "oral-gut-liver axis" concept. However, little is known about the roles of commensal fungi in the disease development. This study aimed to characterize the alterations of oral and gut mycobiota and their roles in MAFLD. Twenty-one MAFLD participants and 20 healthy controls were enrolled. Metagenomics analyses of saliva, supragingival plaques, and feces revealed significant alterations in the gut fungal composition of MAFLD patients. Although no statistical difference was evident in the oral mycobiome diversity within MAFLD and healthy group, significantly decreased diversities were observed in fecal samples of MAFLD patients. The relative abundance of one salivary species, five supragingival species, and seven fecal species was significantly altered in MAFLD patients. Twenty-two salivary, 23 supragingival, and 22 fecal species were associated with clinical parameters. Concerning the different functions of fungal species, pathways involved in metabolic pathways, biosynthesis of secondary metabolites, microbial metabolism in diverse environments, and carbon metabolism were abundant both in the oral and gut mycobiomes. Moreover, different fungal contributions in core functions were observed between MAFLD patients and the healthy controls, especially in the supragingival plaque and fecal samples. Finally, correlation analysis between oral/gut mycobiome and clinical parameters identified correlations of certain fungal species in both oral and gut niches. Particularly, Mucor ambiguus, which was abundant both in saliva and feces, was positively correlated with body mass index, total cholesterol, low-density lipoprotein, alanine aminotransferase, and aspartate aminotransferase, providing evidence of a possible "oral-gut-liver" axis. The findings illustrate the potential correlation between core mycobiome and the development of MAFLD and could propose potential therapeutic strategies.

An Antimicrobial Fabric Using Nano-Herbal Encapsulation of Essential Oils.

Lab coats are widely used in biohazard laboratories and healthcare facilities as protective garments to prevent direct exposure to pathogens, spills, and burns. These cotton-based protective coats provide ideal conditions for microbial growth and attachment sites due to their porous nature, moisture-holding capacity, and retention of warmth from the user's body. Several studies have demonstrated the survival of pathogenic bacteria on hospital garments and lab coats, acting as vectors of microbial transmission. A common approach to fix these problems is the application of antimicrobial agents in textile finishing, but concerns have been raised due to the toxicity and environmental effects of many synthetic chemicals. The ongoing pandemic has also opened a window for the investigation of effective antimicrobials and eco-friendly and toxic-free formulations. This study uses two natural bioactive compounds, carvacrol and thymol, encapsulated in chitosan nanoparticles, which guarantee effective protection against four human pathogens with up to a 4-log reduction (99.99%). These pathogens are frequently detected in lab coats used in biohazard laboratories. The treated fabrics also resisted up to 10 wash cycles with 90% microbial reduction, which is sufficient for the intended use. We made modifications to the existing standard fabric tests to better represent the typical scenarios of lab coat usage. These refinements allow for a more accurate evaluation of the effectiveness of antimicrobial lab coats and for the simulation of the fate of any accidental microbial spills that must be neutralized within a short time. Further studies are recommended to investigate the accumulation of pathogens over time on antimicrobial lab coats compared to regular protective coats.

Microbial trace investigation throughout the entire chicken supply chain based on metagenomic high-throughput sequencing

As poultry possesses a high risk of contamination by various pathogens and has repeatedly been linked to foodborne outbreaks, ensuring microbiological safety throughout the chicken production chain is essential. In this study, bacterial communities in chickens and associated environments (n = 72), including feces, floors, gloves, and worktables, were trace investigated from the broiler farm, slaughterhouse, meat processing plant, and the market by amplicon sequencing of the V4 region of the 16S rRNA. The bacterial composition in live chickens along the production chain significantly changed across the stages, with distinct microbiota noted at each step. Pseudomonas, Shewanella, Acinetobacter, and Psychrobacter were dominant in the final products. Staphylococcus was abundant in live birds originally (36.83 %) but dramatically decreased after slaughter (3.07 %, 0.06 %, and 0.42 % in slaughtered, processed, and market carcasses, respectively), which may be attributed to defeathering. The proportion of Enterobacteriaceae, Acinetobacter, and Pseudomonas increased from 0.95 %, 0.03 %, and 0.04 % before slaughter to 13.57 %, 34.19 %, and 21.90 %, respectively, after slaughter, highlighting the importance of hygiene management in the succeeding steps. Diversity analysis revealed the possibility of bacterial transmission between samples from the processing plant and the market. Source tracking was performed to identify microbial contamination routes in the chicken microbiome; the major bacterial sources in the final products were the samples from the processing plant (such as processed carcasses, gloves, and worktables), accounting for 93.53 % of the total microbial sources. These results suggest that in-depth knowledge of microbial transmission between chickens and their surroundings can facilitate a precise understanding of microbiological concerns across the poultry production system and help establish safety management measures for the poultry industry.

Transmission of oral microbiota to the biliary tract during endoscopic retrograde cholangiography

BackgroundEndoscopic retrograde cholangiography (ERC) possesses a translocation risk of microbes to the biliary system. We studied bile contamination during ERC and its impact on patients’ outcome in a real-life-situation.MethodsNinety-nine ERCs were analyzed and microbial samples were taken from the throat before and from bile during ERC and from irrigation fluid of the duodenoscope before and after ERC.Results91.2% of cholangitis patients had detectable microbes in the bile (sensitivity 91%), but the same was true for 86.2% in the non-cholangitis group. Bacteroides fragilis (p=0.015) was significantly associated with cholangitis. In 41.7% of ERCs with contaminated endoscopes these microbes were found in the bile after the procedure. Analysis of duodenoscopes’ irrigation liquid after ERC matched the microbial bile analysis of these patients in 78.8%. Identical microbial species were in throat and in bile samples of the same ERC in 33% of all cases and in 45% in the non-cholangitis group. Transmission of microbes to the biliary tract did not result in more frequent cholangitis, longer hospital stays, or worse outcome.ConclusionsDuring ERC bile samples are regularly contaminated with microbes of the oral cavity but it did not affect clinical outcome.

Risk of microbial transmission by reusing gloves after alcohol-based hand hygiene

Disinfection of gloves might reduce the workload of healthcare workers, protect the environment, and bring economic benefits. Thus, the safety of hand hygiene of gloved hands is an important issue. We aimed to evaluate the risk of microbial transmission by comparing residual micro-organisms after multiple patient contacts, with or without gloves, in clinical practice. Researchers, two with gloved hands (single or double gloves) and one with bare hands, made rounds of patients, followed by alcohol-based hand rub. Hand imprints were obtained before and after the rounds and cultured. The number of colony-forming units (cfu) of gloved and bare hands was compared, and the colony distribution was evaluated semi-quantitatively by hand region. A total of 108 imprints were obtained after 10 rounds. The median cfu counts were significantly higher in the gloved hands (single and double) than in the bare hands (9.00 vs 3.50, P=0.028). The cfu counts of single- and double-gloved hands were higher after than before contact (P=0.044 and P=0.001, respectively). Carbapenem-resistant Acinetobacter baumannii was identified in a pair of double gloves after a round, which included patients with the same organism with identical antibiotic susceptibility results. The mean percentage of colony-growing compartments from gloved hands was significantly higher than that of bare hands in the finger and wrist regions (P=0.019 and P=0.049, respectively). Compared with bare hands, reuse of gloves increased residual microbial colonies and potential for transmission of multi-drug-resistant organisms, even after using alcohol-based hand rub.

Isolation of Pathogenic Bacteria from Equipment of the Care Units, Hands and Mobile Devices for Medical Staff in Educational Al-Hussein Hospital

Bacterial contamination of intensive care units is of medical concern because it is one of the large risk factors of ICU -acquired infections and centre point of multi-drug resistant pathogens . Cell phones are important source of the microbial transmission as human pathogens also may be cause increased risk for incidence of bacterial infections as well as natural microbiota of human skin .The aim of this study to isolate and diagnose bacteria from intensive care units and mobile devices for medical staff in these units at Educational Al -Hussein Hospital In the city of Nasiriyah. Collection of samples from teaching Al-Hussein hospital, the number of samples 100 distributed Between Swabs of mobiles(30) teaching Al-Hussein hospital medical staffs and ( 50) from hands of nursing and worker and Technicians and doctor Stethoscope also collecting samples(20) swab from department of ICU (Intensive care unit),CCU (Critical care unit), RCU (Respiratory care unit) collect the samples from medical equipment in care unit (ECG (Electro cardio graph), DC- Shock, Suction Device (sucker) , Monitor Device and Ventilator Device )analyzed by standard Bacteriological methods. The frequency pathogenic bacteria obtained in clinical isolates from the sections was 60 out of 20 swab. The maximum frequency of E. coli is 15 isolates by (25)%, most of them in Ventilator Device, The lowest frequency was for Staphylococcus epidermitis with 3 isolates by (5)%, mostly in Suction unit(sucker)and The positive culture was (32) which is more than negative culture(18) out of 50 swabs, But higher positive culture found in a stethoscope with 8 isolates (25)% followed by in hands of technician , Workers , with 7 isolates (21.8)% Respectively as well as highest number and percentage of bacterial contaminated on phone of medical and health staffs were E.coli, Enterococcus faecalis(16.3 ) % Respectively followed by Staphylococci aureus (14.5%), and Klebsiella pneumonia (12.7%) .bacterial cultures found at higher rate among age groups (31-40) years by 56.3%. But the female showed higher rate of bacterial cultures compares to males by 56.2% . Keywords: intensive care units( ICU ) , Bacterial contamination , E.coli , Hospital

Mother-to-infant microbiota transmission and infant microbiota development across multiple body sites

Early-life microbiota seeding and subsequent development is crucial to future health. Cesarean-section (CS) birth, as opposed to vaginal delivery, affects early mother-to-infant transmission of microbes. Here, we assess mother-to-infant microbiota seeding and early-life microbiota development across six maternal and four infant niches over the first 30days of life in 120 mother-infant pairs. Across all infants, we estimate that on average 58.5% of the infant microbiota composition can be attributed to any of the maternal source communities. All maternal source communities seed multiple infant niches. We identify shared and niche-specific host/environmental factors shaping the infant microbiota. In CS-born infants, we report reduced seeding of infant fecal microbiota by maternal fecal microbes, whereas colonization with breastmilk microbiota is increased when compared with vaginally born infants. Therefore, our data suggest auxiliary routes of mother-to-infant microbial seeding, which may compensate for one another, ensuring that essential microbes/microbial functions are transferred irrespective of disrupted transmission routes.

Diet and high altitude strongly drive convergent adaptation of gut microbiota in wild macaques, humans, and dogs to high altitude environments.

Animal gut microbiota plays an indispensable role in host adaptation to different altitude environments. At present, little is known about the mechanism of animal gut microbiota in host adaptation to high altitude environments. Here, we selected wild macaques, humans, and dogs with different levels of kinship and intimate relationships in high altitude and low altitude environments, and analyzed the response of their gut microbiota to the host diet and altitude environments. Alpha diversity analysis found that at high altitude, the gut microbiota diversity of wild macaques with more complex diet in the wild environments is much higher than that of humans and dogs with simpler diet (p < 0.05), and beta diversity analysis found that the UniFrac distance between humans and dogs was significantly lower than between humans and macaques (p < 0.05), indicating that diet strongly drive the convergence of gut microbiota among species. Meanwhile, alpha diversity analysis found that among three subjects, the gut microbiota diversity of high altitude population is higher than that of low altitude population (ACE index in three species, Shannon index in dog and macaque and Simpson index in dog, p < 0.05), and beta diversity analysis found that the UniFrac distances among the three subjects in the high altitude environments were significantly lower than in the low altitude environments (p < 0.05). Additionally, core shared ASVs analysis found that among three subjects, the number of core microbiota in high altitude environments is higher than in low altitude environments, up to 5.34 times (1,105/207), and the proportion and relative abundance of the core bacteria types in each species were significantly higher in high altitude environments than in low altitude environments (p < 0.05). The results showed that high altitude environments played an important role in driving the convergence of gut microbiota among species. Furthermore, the neutral community model trial found that the gut microbiota of the three subjects was dispersed much more at high altitude than at low altitude, implying that the gut microbiota convergence of animals at high altitudes may be partly due to the microbial transmission between hosts mediated by human activities.

Infection transmission via mobile phones in a mass gathering setting: Public knowledge, attitudes and practices in Makkah city, Saudi Arabia

BackgroundMobile phones have become part of everyday life with a potential risk for microbial transmission. Makkah is a mass gathering city that may act as hotspots of disease transmission. The contact between public and both visitors and pilgrims to Makkah can't be overlooked, and any small outbreak within the public can be transmitted rapidly to them. AimWe aimed to assess knowledge, attitudes, and practices (KAP) of general population towards infection transmission via mobile phones in Makkah and different characteristics relevant to KAP scores. MethodsA cross-sectional web-based survey was conducted on general population in Makkah city using a snowballing sampling method. Participants answered questions about their KAP towards infection transmission via mobile phone. The overall KAP scores were graded as good, fair, and poor and explored against different population characteristics using suitable statistical methods. ResultsThe study included 385 participants aged 15–64 years. About 88.8% owned personal mobile phone, 3.9% encountering a patient with infections transmitted via mobile phones, and 60.5% know nothing about potential role of mobile phones in infection transmission. Only 16.6% had good knowledge, 64.1% with positive attitudes, and 55.3% reported poor practices. The mean knowledge score was significantly higher among young adults (p = 0.002) and those with higher education (p = 0.005). Their mean attitude and practice scores were significantly higher among older adults (p < 0.001 and p = 0.015), female (p = 0.001 and p = 0.022), and those with higher education (p = 0.036 and p = 0.041) respectively. ConclusionThe overall public knowledge and practices towards the role of mobile phones in infection transmission in Makkah was below average though they have positive attitudes. Raising public awareness is important to decrease the possibility of cross-contamination via mobile phones and to develop adequate preventive strategies in a mass gathering setting like Makkah city.

Hypochlorous acid inactivates oral pathogens and a SARS-CoV-2-surrogate

BackgroundDroplets and aerosols produced during dental procedures are a risk factor for microbial and viral transmission. Unlike sodium hypochlorite, hypochlorous acid (HOCl) is nontoxic to tissues but still exhibits broad microbicidal effect. HOCl solution may be applicable as a supplement to water and/or mouthwash. This study aims to evaluate the effectiveness of HOCl solution on common human oral pathogens and a SARS-CoV-2 surrogate MHV A59 virus, considering the dental practice environment.MethodsHOCl was generated by electrolysis of 3% hydrochloric acid. The effect of HOCl on human oral pathogens, Fusobacterium nucleatum, Prevotella intermedia, Streptococcus intermedius, Parvimonas micra, and MHV A59 virus was studied from four perspectives: concentration; volume; presence of saliva; and storage. HOCl solution in different conditions was utilized in bactericidal and virucidal assays, and the minimum inhibitory volume ratio that is required to completely inhibit the pathogens was determined.ResultsIn the absence of saliva, the minimum inhibitory volume ratio of freshly prepared HOCl solution (45–60 ppm) was 4:1 for bacterial suspensions and 6:1 for viral suspensions. The presence of saliva increased the minimum inhibitory volume ratio to 8:1 and 7:1 for bacteria and viruses, respectively. Applying a higher concentration of HOCl solution (220 or 330 ppm) did not lead to a significant decrease in the minimum inhibitory volume ratio against S. intermedius and P. micra. The minimum inhibitory volume ratio increases in applications of HOCl solution via the dental unit water line. One week of storage of HOCl solution degraded HOCl and increased the minimum growth inhibition volume ratio.ConclusionsHOCl solution (45–60 ppm) is still effective against oral pathogens and SAR-CoV-2 surrogate viruses even in the presence of saliva and after passing through the dental unit water line. This study indicates that the HOCl solution can be used as therapeutic water or mouthwash and may ultimately reduce the risk of airborne infection in dental practice.

Cationic Conjugated Microporous Polymers Coating for Dual‐Modal Antimicrobial Inactivation with Self‐Sterilization and Reusability Functions

AbstractCOVID‐19 pandemic outbreak poses a great threat to human health. Face masks have been considered as important personal protective equipment to prevent the COVID‐19 transmission. However, pathogens can survive up to several days on the fabrics of commercial masks, which increases the risk of direct/indirect microbial transmission. Herein, new cationic conjugated microporous polymers (CCMPs)‐based coating is developed, which possesses extended π‐conjugated skeletons and massive quaternary ammonium salt (QAS) groups, exhibiting dual‐modal antimicrobial inactivation, including sunlight‐driven photodynamic sterilization through the generation of reactive oxygen species and contact sterilization through QAS groups. As a result, the CCMPs coatings can rapidly and efficiently eradicate 99% of model microbes, such as Escherichia coli and Staphylococcus aureus under solar illumination, and also ensure the great antimicrobial effect in the absence of light. More importantly, the CCMPs coatings exhibit excellent durability, reusability as well as antimicrobial stability in humid environment. Contributing to the outstanding processability and formability, CCMPs can be in situ synthesized and coated over fibers through a simple spray procedure. Taken together, the design provides a promising strategy for developing reusable and self‐sterilizing antimicrobial fabrics, particularly for the application of face masks to tackle infectious pathogen and viruses in daily protection and medical applications.

Transmission mode and dispersal traits correlate with host specificity in mammalian gut microbes.

Different host species associate with distinct gut microbes in mammals, a pattern sometimes referred to as phylosymbiosis. However, the processes shaping this host specificity are not well understood. One model proposes that barriers to microbial transmission promote specificity by limiting microbial dispersal between hosts. This model predicts that specificity levels measured across microbes is correlated to transmission mode (vertical vs. horizontal) and individual dispersal traits. Here, we leverage two large publicly available gut microbiota data sets (1490 samples from 195 host species) to test this prediction. We found that host specificity varies widely across bacteria (i.e., there are generalist and specialist bacteria) and depends on transmission mode and dispersal ability. Horizontally-like transmitted bacteria equipped with traits that facilitate switches between host (e.g., tolerance to oxygen) were found to be less specific (more generalist) than microbes without those traits, for example, vertically-like inherited bacteria that are intolerant to oxygen. Altogether, our findings are compatible with a model in which limited microbial dispersal abilities foster host specificity.

Microbial species from multiple maternal body sites shape the developing giant panda (Ailuropoda melanoleuca) cub gut microbiome.

The gut microbiome of the giant panda (Ailuropoda melanoleuca) plays a vital role in nutrient acquisition from its specialized bamboo diet. Giant panda cubs harbour significantly different gut microbiota during their growth and development when feeding on milk before switching to bamboo. The fetal gut is sterile, and following birth, mother-to-infant microbial transmission has been implicated as a seeding source for the infant gut microbiota. Details of this transmission in giant pandas remain unclear. In this study, faecal samples were collected from seven panda mother-cub pairs when the cubs were 4-16 months old. Additional samples from the cubs' diet, soil and drinking water, and multiple body sites of the mothers were collected. Bacterial 16S rRNA gene sequencing and shotgun metagenomic sequencing were performed to determine the source and potential transmission routes of the cub gut microbiome. Source tracking analysis showed that maternal vagina, milk and faeces were the primary contributory sources of microbes, shaping the cub gut microbiome. Bacterial species from maternal faeces persisted the longest in the cub gut. Bacterial species in the diet contributed to the microbial community. Metagenomics analysis indicated that the predicted metabolic pathways of the gut microbiome also varied at different growth stages. Gut colonization with bacteria from various body sites of the mothers provides a foundational microbial community that is beneficial in fulfilling the evolving dietary needs of the cubs. This study suggests that mother-to-cub transmission is indispensable in shaping the gut microbiome of the developing panda cub.

A Review Focusing on Microbial Vertical Transmission during Sow Pregnancy

Microorganisms are closely related to the body's physiological activities and growth and development of the body, and participate in many physiological metabolic activities. Analysis of the structure and source of early colonizing bacteria in the intestinal tract of humans and rodents shows that early colonizing bacteria in the intestinal tract of mammals have solid maternal characteristics, and maternal microbes play an essential role in the formation of progeny intestinal flora. The placental microbiome, maternal microbiome and breast milk microbiome are currently hot topics in the field of life science. This paper discusses the vertical transmission and endogenous sources of the mother-to-piglet microbiome through these three pathways, aiming to provide a new research idea for intervention in the intestinal microbiome in young piglets.

Antimicrobial Coatings: Reviewing Options for Healthcare Applications

Many publications report coatings that exhibit antimicrobial potency applicable to high-touch surfaces and desirable for healthcare settings to contribute to reductions in the occurrence of Hospital Acquired Infections (HAI). In this review, the importance of surface contamination and the transmission of microbes is addressed. The standard strategy to tackle fomites is to implement proper disinfection and cleaning practices and periodically monitor the environment’s cleanliness. However, the probability of recontamination of cleaned surfaces is high. Therefore, an additional first line of defense against pathogen transmission and subsequent infection is the antimicrobial surface that can eliminate or at least repel pathogens, introducing a barrier to the spread of infection. It is a simple concept, but formulating a durable, antimicrobial coating with broad-spectrum antimicrobial and antifouling activities has proven challenging. The challenges and progress made in developing such material are reviewed.

Maternal rumen and milk microbiota shape the establishment of early-life rumen microbiota in grazing yak calves

Early-life gut microbial colonization and development exert a profound impact on the health and metabolism of the host throughout the life span. The transmission of microbes from the mother to the offspring affects the succession and establishment of the early-life rumen microbiome in newborns, but the contributions of different maternal sites to the rumen microbial establishment remain unclear. In the present study, samples from different dam sites (namely, oral, rumen fluid, milk, and teat skin) and rumen fluid of yak calves were collected at 6 time points between d 7 and 180 postpartum to determine the contributions of the different maternal sites to the establishment of the bacterial and archaeal communities in the rumen during early life. Our analysis demonstrated that the dam's microbial communities clustered according to the sites, and the calves' rumen microbiota resembled that of the dam consistently regardless of fluctuations at d 7 and 14. The dam's rumen microbiota was the major source of the calves' rumen bacteria (7.9%) and archaea (49.7%) compared with the other sites, whereas the potential sources of the calf rumen microbiota from other sites varied according to the age. The contribution of dam's rumen bacteria increased with age from 0.36% at d 7 to 14.8% at d 180, whereas the contribution of the milk microbiota showed the opposite trend, with its contribution reduced from 2.7% at d 7 to 0.2% at d 180. Maternal oral archaea were the main sources of the calves' rumen archaea at d 14 (50.4%), but maternal rumen archaea became the main source gradually and reached 66.2% at d 180. These findings demonstrated the potential microbial transfer from the dam to the offspring that could influence the rumen microbiota colonization and establishment in yak calves raised under grazing regimens, providing the basis for future microbiota manipulation strategies during their early life.

Assessment of the Occupational Risk of Tuberculosis & Air Borne Infection Control in High-Risk Hospital Wards and Its Implications on Healthcare Workers in a Tertiary Care Hospital in South India.

Introduction The indoor air in hospitals could play a significant role in the transmission of a wide array of infections, especially in respiratory intensive care units, pulmonary outpatient departments, and other areas. Unprotected coughing and sneezing may facilitate the release of aerosols and contaminate the indoor environment. The majority of infections transmitted through these modes include viral diseases, including tuberculosis (TB), influenza, and measles, among several others. Moreover, the possibility of direct and indirect transmission of microbes by air has been underestimated in hospital settings, especially in developing countries. This studytherefore was carried out to assess the burden of microbes in the air of selected wards in a tertiary care hospital and evaluate the occupational risk of some infections among healthcare workers (HCWs). Methods This study was carried out between September 2019 and February 2021 at a tertiary care teaching hospital in South India. A total of 30 symptomatic healthcare workers (HCWs) were included in the study and were screened for present and past tuberculosis (TB) as well as other lower respiratory tract infections. A tuberculin skin test, chest X-ray, and sputum acid-fast staining were performed on all the HCWs who were negative for other bacterial infections and were symptomatic. The study was conductedin coordination with the pulmonology department. Active monitoring of air was performed by microbiological air sampler in the respiratory intensive care unit (RICU) and other high-risk areas including the pulmonology outpatient department (OPD), the radiology OPD, and the microbiology department. Results Sputum for tuberculousbacteriawas positive in four (16.6%) HCWs. The chest X-ray showed radiological findings suggestive of TB in five (20.8%) HCWs. Three (12.5%) HCWs who were screened for extrapulmonary TBrevealed one (33.3%) was positive for TB of the hip joint. Among the HCWs, eight (33%) returned positive tuberculin tests. Assessment of the hospital air in theRICU revealedthe bacterial count (288 CFU/m3) exceeded the normal limit (≤50 CFU/m3). The COVID-19 isolation ward showed the lowest bacterial count (06 CFU/m3) and no fungi. The predominant bacterial isolates were gram-positive cocci in clusters (Methicillin-sensitive Staphylococcus aureus). After proper disinfection and correction of ventilation techniques, the resampling results noted microbial colonies under normal limits. Conclusion A high burden of TB was noted among the HCWs. The airborne infection control strategies are essential to minimize the risk ofnosocomial infections and occupational TB risk to HCWs. Most microbes are transmitted through the airborne route and therefore it is extremely important to take measures to control the transmission of such pathogens in hospital settings.

The distinct microbial community patterns and pathogen transmission routes in intensive care units

While the microbiome in indoor environments such as hospitals has drawn increasing attention, the transmission routes especially for pathogens in ICUs remain largely unexamined. In this study, we have explored the distinct bacterial communities of ICU compared with Non-ICU in hospital wards. We have then clarified their different transmission patterns by means of microbial source tracking, with results suggesting that bedrail and inside floor were hubs in two wards, respectively. Streptococcus , Staphylococcus were identified as “Transfer-Easy taxa” that were found in both ICU and Non-ICU settings, with potential pathogenicity and cases recorded. We have also detected another 15 pathogenic genera in hospital environment, including Pseudomonas and Acinetobacter , and charted how these pathogenic microorganisms affect patients, demonstrating that there were far more strong routes for pathogens transmitted from environment to patients in ICU. In summary, this work investigates patterns of bacterial transmission in hospital settings, highlights pathogenic genera that are likely to transfer from the environment to humans and cause nosocomial infection, which could provide guidance for healthcare system monitoring and co-infection avoidance. • Microbial community patterns and transmission routes differ between ICU and non-ICU wards. • Several genera with strong transmission capacity could transfer from the outside environment to patients. • A group of pathogens discovered in ICU wards indicate a high probability of co-infection.

Effects of diet shift on the gut microbiota of the critically endangered Siberian Crane

Wetlands worldwide have suffered from serious degradation and transformation, leading to waterbirds increasingly dependent on agricultural fields for feeding. Although gut microbiota is an essential component of host health, the impacts of agricultural feeding on gut microbial community and pathogen transmission remain poorly understood. To fill this knowledge gap, we used 16S rRNA sequencing to characterize the fecal bacterial community of the Siberian Crane (Grusleucogeranus), a Critically Endangered species, that recently has shifted its foraging from largely Vallisneria tubers in Poyang Lake natural wetlands to crops (i.e., rice seeds and lotus rhizomes) in agricultural fields. We compared the bacterial communities between tuber foraging cranes and crop foraging cranes. Our results indicate that diet shift greatly modified the gut microbiota diversity, composition and function. Crop foraging cranes had higher microbiota diversity than tuber foraging cranes. The alteration in microbiota composition and function were correlated with change in food nutrition. Tuber (i.e., high in fiber) foraging cranes were enriched in Clostridiaceae with fiber digestion ability, and crop (i.e., high in carbohydrate) foraging cranes were enriched in bacterial taxa and functions related to carbohydrate metabolism. The flexibility of gut microbiota might enhance Siberian Cranes’ ability to adapt to novel diet and environment. However, many enriched families in crop foraging cranes were pathogenic bacteria, which might increase the susceptibility of cranes to pathogenic infection. Special caution should be taken to agricultural feeding waterbirds in Asia, where the widespread poultry-keeping in over-harvested rice fields might increase the transmission probability of pathogenetic bacteria among wild birds, domestic poultry and humans.