Aerobic and anaerobic microbiology of infections after trauma in children

Diagnosis, management, and outcomes of pediatric tracheostomy-associated infections: A scoping review

BACKGROUND

Children with tracheostomy are frequently admitted to the hospital for tracheostomy-associated respiratory infections (TRAINs). However, there remains a paucity of evidence to direct the diagnosis, treatment, and prevention of TRAINs. An important first step to addressing this knowledge gap is to synthesize existing data regarding TRAINs to inform current practice and facilitate innovation.

DATA SOURCES

We searched PubMed, Embase, Cochrane Library, CINAHL, and Web of Science from inception to October 2020. Original research articles and published abstracts including children and young adults 0-21 years of age with tracheostomy were included. Included studies assessed the clinical definitions of and risk factors for TRAINs, microbiologic epidemiology and colonization of tracheostomies, and treatment and outcomes of TRAINs.

DATA SYNTHESIS

Out of 5755 studies identified in the search, 78 full-text studies were included in the final review. A substantial number of studies focused on the detection of specific pathogens in respiratory cultures including Pseudomonas aeruginosa. Several different definitions of TRAIN including clinical, microbiologic, and laboratory testing results were utilized; however, no uniform set of criteria were identified. The few studies focused on treatment and prevention of TRAIN emphasized the role of empiric antimicrobial therapy and the use of inhaled antibiotics.

CONCLUSIONS

Despite a growing number of research articles studying TRAINs, there is a paucity of prospective interventional trials to guide the diagnosis, treatment, and prevention of respiratory disease in this vulnerable population. Future research should include studies of interventions designed to improve short- and long-term respiratory-related outcomes of children with tracheostomy.

Identification of population of bacteria from culture negative surgical site infection patients using molecular tool

BACKGROUND

Managing surgical site infections, with negative culture report in routine diagnosis is a common dilemma in microbiology accounting more than 30% worldwide. The present study attempted to identify the presence of bacterial spp. if any in wound aspirates/swabs of culture negative surgical site infections of hospitalised patients using molecular tools.

METHODS

Ninety-seven patients with post-operative SSI whose wound swabs/aspirate were negative in the conventional aerobic culture after 72 h of incubation were analysed by 16S rRNA gene specific broad range PCR. The amplified DNA fragments were sequenced by Sanger DNA sequencing method and homology of the sequence were matched using NCBI BLAST (NCBI, USA) RESULTS: Of the 97 patients, 16S rRNA based broad range PCR assay could identify the presence of bacterial pathogen in 53(54.63%) cases, of which 29 isolates were supposed to be of viable but non-culturable bacteria (VBNC), 07 were of obligatory anaerobes and 13 were of unculturable bacteria, 04 were with poly bacterial infections.

CONCLUSIONS

Our study highlights the usefulness of PCR assay in detecting the presence of any VBNC, anaerobes and unculturable bacteria in SSI patients regardless of how well the bacteria may or may not grow in culture. Measures should be taken to use anaerobic culture system and PCR diagnosis along with conventional culture to detect the VBNC and unculturable bacteria where Gram stain is positive for better patient care.

Epidemiological trends of fatal pediatric trauma: A single-center study

To evaluate the potential risk factors which increase the incidence of post-trauma complications and mortality in pediatric population.A retrospective cohort study was conducted on patients below 18 years of age with a fatal outcome who were admitted to an Indian level-1 trauma center between January 2013 and December 2015. This cohort was analyzed to determine the demographics, injury mechanism, injury severity, microbiological profile, and cause of death.In total, 320 pediatric patients with a fatal outcome were studied which showed male preponderance (71.56%). The median age of the patients was 11 years (range, 0.14-18 years). Median duration of stay was 1 day (range, 0-183 days). Fall and road traffic accidents were the common mechanisms of trauma while the main injury was head injury. In total, 857 clinical samples were received from 56 patients. The clinical samples from 35 (10.94%) patients were culture positive. Culture-proven infections were significantly correlated with the length of hospital stay (P = .001). In total, 212 organisms were isolated from 193 positive samples of which gram-negative bacteria were predominant (89.15%). The most common gram-positive bacterial isolate was Staphylococcus aureus (12, 52.17%), while Acinetobacter baumannii (66, 34.92%) was the most prevalent gram-negative bacterial isolate followed by Pseudomonas spp. (36, 19.05%), Klebsiella pneumoniae (35, 18.52%), and Escherichia coli (16, 8.47%). Up to 100% multidrug resistance was seen in both gram-positive and gram-negative bacterial isolates. The first 24 hours after trauma were the deadliest for our patients. Head/central nervous system injury was the primary cause of disabilities and early death whereas infection attributed to prolonged hospital stay.From these observations we concluded that management of pediatric trauma requires expert, multidisciplinary, and timely interventions. Moreover, nosocomial infections with multidrug resistant gram-negative bacteria challenges the accepted tenets of trauma care affecting the outcome of the pediatric population. Early identification of such high-risk patients' infection may facilitate early intervention. Thus, many deaths in pediatric group are preventable.

Noma: Overview of a Neglected Disease and Human Rights Violation

Noma is an orofacial gangrene affecting malnourished children and mainly observed in tropical countries, particularly sub-Saharan Africa. Epidemiological data on noma are scarce, but a current estimate of the global incidence is 30,000-40,000 cases per year, with a mortality rate of approximately 85% and a burden of disease calculated to be a loss of 1-10 million disability-adjusted life years. The etiology of noma is multifactorial with malnutrition as an ever present factor, often in combination with concomitant diseases, such as measles, malaria, and human immunodeficiency virus (HIV), and poor oral hygiene. The pathogenesis is a fast-spreading, noncontagious gangrenous infection occurring in the face, often preceded by acute necrotizing gingivitis, and stomatitis. Rare microbiological studies suggest an opportunistic infection caused by an imbalance in normal intraoral microorganisms. Prevention lies in food security, measles vaccination, prevention of malaria and HIV, including the early detection and treatment of necrotizing gingivitis and stomatitis. Early treatment with antibiotics may prevent gangrene or reduce its extent. Late treatment consists of surgical rehabilitation, which is often complex. However, access to medical care is very limited for noma patients due to the extremely poor conditions in which they live that are frequently located in remote rural areas. The authors support the United Nations Human Rights Council Resolution 19/7 adopted on March 22, 2012 "The right to food," and advocate for the inclusion of noma on the list of neglected tropical diseases to encourage more medical and institutional attention for this often lethal or very mutilating infectious gangrene.

Anaerobic infections in surgical wards: a two year study

BACKGROUND AND OBJECTIVES

Anaerobic bacteria are recognized as important pathogens in surgical infections. However, they are the most overlooked microorganisms by the clinic and the laboratory because of the tedious culture techniques with longer turn-around times. The study was aimed to analyze the frequency of anaerobic bacterial surgical infections and their predisposing factors.

MATERIALS AND METHODS

A retrospective study was conducted over a period of two years including patients with surgical infections. The specimens were processed by Gram staining, aerobic and anaerobic culture. The anaerobic bacteria were isolated using standard procedures. The predisposing factors and clinical presentation were studied in these patients.

RESULTS

A total of 261 specimens were received from patients with diverse infections from surgical wards. Ninety-one anaerobes were isolated from 64 (24.5%) surgical patients with a predominance of Gram-negative bacilli (37.4%). Anaerobic bacteria as monomicrobial isolates were seen in 21.9% isolates. Anaerobic bacterial isolation along with aerobic bacteria was seen in 71.9% of patients and polymicrobial anaerobic growth was detected in 6.3% of patients. Diabetes mellitus (28, 43.8%) was found to be the most frequent predisposing factor. Bacteroides fragilis group (20.9%) were the most frequent anaerobic Gram-negative bacilli followed by Prevotella spp. (12.1%). Peptostreptococcus anaerobius was the predominant anaerobic cocci isolated (14.3%). Necrotizing fascitis (34.4%) was the most common clinical presentation with anaerobic etiology followed by deep seated abscesses (23.4%).

CONCLUSION

Anaerobic bacteria were isolated from a significant proportion of surgical infections. To avoid therapeutic failures, anaerobic bacteria in surgical infections need to be recognized by surgeons and laboratorians.

Polymicrobial wound infections: pathophysiology and current therapeutic approaches

Acute and chronic wounds represent a very common health problem in the entire world. The dermal wounds are colonized by aerobic and anaerobic bacterial and fungal strains, most of them belonging to the resident microbiota of the surrounding skin, oral cavity and gut, or from the external environment, forming polymicrobial communities called biofilms, which are prevalent especially in chronic wounds. A better understanding of the precise mechanisms by which microbial biofilms delay repair processes together with optimizing methods for biofilm detection and prevention may enhance opportunities for chronic wounds healing. The purpose of this minireview is to assess the role of polymicrobial biofilms in the occurrence and evolution of wound infections, as well as the current and future preventive and therapeutic strategies used for the management of polymicrobial wound infections.

Microarray analysis of microbiota of gingival lesions in noma patients

Noma (cancrum oris) is a gangrenous disease of unknown etiology affecting the maxillo-facial region of young children in extremely limited resource countries. In an attempt to better understand the microbiological events occurring during this disease, we used phylogenetic and low-density microarrays targeting the 16S rRNA gene to characterize the gingival flora of acute noma and acute necrotizing gingivitis (ANG) lesions, and compared them to healthy control subjects of the same geographical and social background. Our observations raise doubts about Fusobacterium necrophorum, a previously suspected causative agent of noma, as this species was not associated with noma lesions. Various oral pathogens were more abundant in noma lesions, notably Atopobium spp., Prevotella intermedia, Peptostreptococcus spp., Streptococcus pyogenes and Streptococcus anginosus. On the other hand, pathogens associated with periodontal diseases such as Aggregatibacter actinomycetemcomitans, Capnocytophaga spp., Porphyromonas spp. and Fusobacteriales were more abundant in healthy controls. Importantly, the overall loss of bacterial diversity observed in noma samples as well as its homology to that of ANG microbiota supports the hypothesis that ANG might be the immediate step preceding noma.

Microflora in maxillofacial infections--a changing scenario?

PURPOSE

Advances in isolation and culturing techniques have brought the role of anaerobic bacteria-causing maxillofacial infections to the fore. Recent literature also favors the role of anaerobes in maxillofacial infections. A prospective clinical and microbiological study was designed to check the validity of such claims.

PATIENTS AND METHODS

This study included 88 patients who fulfilled the inclusion criteria. Pus was obtained by aspirating the involved spaces and culture and sensitivity tests were performed to determine the microbes involved and their sensitivity to various antibiotics.

RESULTS

Upon isolating the various organisms causing infection, it was found that 68.2% were aerobes, 13.6% were mixed infections, and 9.1% were anaerobes. Streptococcus and Peptostreptococcus species were the most common among aerobes and anaerobes, respectively. On determining sensitivity to penicillin, 81.3% were sensitive and 18.8% were resistant. Coagulase-negative Staphylococcus and Staphylococcus aureus were predominantly resistant to penicillin.

CONCLUSION

Analysis of the results indicated no change in microflora-causing infections in the maxillofacial region and penicillin remains the drug of choice in treating these infections.

Microbiology and management of soft tissue and muscle infections

This review summarizes the microbiological aspects and management of soft tissue and muscle infections. The infections presented are: impetigo, folliculitis, furunculosis and carbuncles, cellulitis, erysipelas, infectious gangrene (includes necrotizing fasciitis or streptococcal gangrene, gas gangrene or clostridium myonecrosis, anaerobic cellulites, progressive bacterial synergistic gangrene, synergistic necrotizing cellulitis or perineal phlegmon, gangrenous balanitis, and gangrenous cellulitis in the immunocompromised patient), secondary bacterial infections complication skin lesions, diabetic and other chronic superficial skin ulcers and subcutaneous abscesses and myositis. These infections often occur in body sites or in those that have been compromised or injured by foreign body, trauma, ischemia, malignancy or surgery. In addition to Group A streptococci and Staphylococcus aureus, the indigenous aerobic and anaerobic cutaneous and mucous membranes local microflora usually is responsible for polymicrobial infections. These infections may occasionally lead to serious potentially life-threatening local and systemic complications. The infections can progress rapidly and early recognition and proper medical and surgical management is the cornerstone of therapy.

Interleukin-6 treatment reverses apoptosis and blunts susceptibility to intraperitoneal bacterial challenge following hemorrhagic shock*

BACKGROUND

Resuscitation from hemorrhagic shock (HS) predisposes to subsequent infections. Susceptibility to infection following sepsis has been attributed to apoptosis. Interleukin (IL)-6 has been shown to have antiapoptotic properties and to decrease postresuscitation inflammation in rodent and porcine models of HS.

OBJECTIVE

The objective was to determine if HS increases host susceptibility to infection, if IL-6 administration at resuscitation reduces this susceptibility, and if changes in susceptibility to infection are accompanied by parallel changes in apoptosis.

SUBJECTS AND INTERVENTIONS

Mice were randomized into three groups-HS, sham, and no-surgery control-and each group was further randomized to receive either IL-6 (3 microg/kg; HS/IL-6) or placebo (HS/P) at the start of resuscitation. In the HS-infection protocol, each mouse was challenged intraperitoneally the next day with a sublethal dose of Staphylococcus aureus (4x107 colony-forming units); 24 hrs later, the peritoneal cavity was lavaged and the major organs were harvested for culture. In the HS-apoptosis protocol, the livers were harvested the next day and analyzed by means of the terminal deoxynucleotidyl transferase dUTP-biotin nick-end-labeling (TUNEL) assay.

RESULTS

HS/P mice had a six- to eight-fold increase in total bacterial counts in comparison with sham and control mice that was attributable to a seven- to nine-fold increase in liver burden. IL-6 treatment reduced total and liver bacterial counts in HS/IL-6 mice by 62% and 69%, respectively, to levels statistically indistinguishable from IL-6-treated sham and control mice. The number of TUNEL-positive liver cells in the HS/P group was increased eight-fold vs. that in the sham group (p=.002); IL-6 resuscitation completely reversed the HS-induced increase in TUNEL-positive cells in the HS/IL-6 group (p=.002).

CONCLUSIONS

IL-6 treatment at resuscitation eliminated the HS-mediated increase in total and liver bacterial burden and protected the liver from HS-induced apoptosis. Reduced liver apoptosis may explain the ability of IL-6 to blunt the HS-induced increase in susceptibility to bacterial challenge.

Skin and Soft-Tissue Infections among Tsunami Survivors in Southern Thailand

Among 777 patients transferred to 4 hospitals in Bangkok from southern Thailand after the tsunami of 26 December 2004, there were 515 with skin and soft-tissue infections. The most common organisms isolated were Aeromonas species (145 [22.6%] of 641 isolates from 305 patients). Most isolates were susceptible to aminoglycosides, third- and fourth-generation cephalosporins, quinolones, and imipenem but were resistant to amoxicillin-clavulanate and first-generation cephalosporins.

Recovery of anaerobic bacteria from wounds after lawn-mower injuries

Accidental injury while using lawn mowers can cause serious infectious complications in the injured extremity. Anaerobic bacteria were rarely recovered from this infection. Two children who sustained injury in their foot by a lawn mower developed severe wound infection. Culture of the wound from 1 patient had heavy growth of Clostridium bifermentans and Peptostreptococcus magnus, and the culture from the other child grew Clostridium perfringens. Antimicrobial therapy directed at the pathogens and vigorous surgical irrigation and debridement led to complete recovery from the infection. This report illustrates the recovery of anaerobic bacteria from children that had wound infection after lawn-mower injury.

Microbiology and management of myositis

This review summarizes the microbiology, management, and prevention of myositis. Muscular infections frequently occur in areas of the body that have been compromised or injured by a foreign body, trauma, ischemia, injection of illicit drug, malignancy, or surgery. These infections can develop very rapidly to life-threatening systemic illness. The predominant pathogens are Staphylococcus aureus, Group A streptococci (GAS), gram-negative aerobic and facultative bacilli, and the indigenous aerobic and anaerobic cutaneous and mucous membranes local microflora. Pyogenic myositis can be classified into either GAS necrotizing myositis, clostridial myonecrosis (gas gangrene), or nonclostridial (crepitant) myositis. Intensive surgical and medical therapy that includes the administration of intravenous fluids and antimicrobial therapy is an essential element in management of muscle infection.

Wound microbiology and associated approaches to wound management

The majority of dermal wounds are colonized with aerobic and anaerobic microorganisms that originate predominantly from mucosal surfaces such as those of the oral cavity and gut. The role and significance of microorganisms in wound healing has been debated for many years. While some experts consider the microbial density to be critical in predicting wound healing and infection, others consider the types of microorganisms to be of greater importance. However, these and other factors such as microbial synergy, the host immune response, and the quality of tissue must be considered collectively in assessing the probability of infection. Debate also exists regarding the value of wound sampling, the types of wounds that should be sampled, and the sampling technique required to generate the most meaningful data. In the laboratory, consideration must be given to the relevance of culturing polymicrobial specimens, the value in identifying one or more microorganisms, and the microorganisms that should be assayed for antibiotic susceptibility. Although appropriate systemic antibiotics are essential for the treatment of deteriorating, clinically infected wounds, debate exists regarding the relevance and use of antibiotics (systemic or topical) and antiseptics (topical) in the treatment of nonhealing wounds that have no clinical signs of infection. In providing a detailed analysis of wound microbiology, together with current opinion and controversies regarding wound assessment and treatment, this review has attempted to capture and address microbiological aspects that are critical to the successful management of microorganisms in wounds.