Streptococcus anginosus is associated with postoperative intraabdominal collections in appendicitis

Intracranial Empyema in Children: A Single-center Retrospective Case Series

We conducted a retrospective, observational study of 42 children with intracranial empyema admitted to a pediatric neurosurgical center over a 9-year period. Intracranial empyema is rare, but causes significant morbidity and mortality. Twenty-eight cases had neurosurgical source control, more commonly for subdural collections. Streptococcus anginosus group bacteria are important pathogens in subdural empyema, whose isolation predicts more complicated postoperative courses.

Bacterial peritonitis in paediatric appendicitis; microbial epidemiology and antimicrobial management

BACKGROUND

Appendicitis remains a common surgical emergency in children. Empirical antibacterial treatment is indicated to reduce infective complications. We investigate the bacterial pathogens identified intra-operatively during appendectomies in children to guide empirical surgical antimicrobial prophylaxis options.

METHODS

A retrospective analysis of patients (< 18 years old) undergoing an appendectomy across a multisite London hospital (Nov 2019-March 2022) was undertaken. Patient-related outcomes including length of hospital stay (LOS), days of antibacterial therapy (DOT), intra-operative microbiology and post-operative radiology reports were interrogated.

RESULTS

304 patients underwent an appendectomy during this period; 39.1% of patients had intraoperative samples cultured. Bacterial pathogens were found in 73/119 (61.3%) cases; the most common isolates being Escherichia coli (42.0%), Pseudomonas aeruginosa (21.0%), milleri Streptococcus spp. (14.3%) and Bacteroides fragilis (5.9%). Polymicrobial infection was common (32/73). Isolation of Pseudomonas spp. from intra-operative sampling was associated with a greater LOS (7.0 vs. 5.0 days; p = 0.011) but nil effect on the incidence of postoperative collections. Presence of milleri Streptococcus spp. was associated with longer LOS (7.0 vs. 5.0 day; p = 0.007), DOT (12.0 vs. 8.5 day; p = 0.007) but had no observed outcome on postoperative collections (29.4% vs. 18.6%; p = 0.330). 48% of E. coli positive cultures were co-amoxiclav resistant and prolonged LOS compared to the non-resistant group (7.0 vs. 5.0 days; p = 0.040) but had no difference in post-operative collections (29.2% vs. 17.9%; p = 0.260).

CONCLUSION

A high proportion of children with appendicitis have Pseudomonas spp. isolated, leading to a prolonged LOS. Evolving Enterobacterales resistance and the presence of Pseudomonas spp. necessitate extended antibacterial coverage for paediatric appendectomies with evidence of peritonitis.

Using Microbiology Culture in Pediatric Appendicitis to Risk Stratify Patients: A Cohort Study

Background: We sought to investigate the value of intra-operative microbiology samples in pediatric appendicitis. Proposed benefits include tailoring post-operative antimicrobial management, risk-stratifying patients, and reducing post-operative intra-abdominal abscess formation. Patients and Methods: All cases of appendicitis managed with appendicectomy in a single center were collected from January 2015 to August 2020. Intra-operative microbiology samples were taken routinely. Post-operative outcomes were analyzed with reference to culture and sensitivity results. Histologic findings were further categorized as normal, simple, or complex. Results: Six hundred seventy-eight children had appendicectomies, and 608 had both microbiology and histology samples taken. Intra-abdominal fluid collection and subsequent intervention rates were 22% and 9%, respectively. There were more collections in those with a culture positive result (p < 0.001), and those growing each of three recognized organisms, Escherichia coli (p < 0.001), Pseudomonas aeruginosa (p = 0.01), and Streptococcus anginosus group (p < 0.001). Intervention rate was higher in the culture-positive result group (p = 0.002) and the Streptococcus anginosus group (p < 0.001). Conclusions: This study shows an increased risk of developing a collection with the isolation of one of three key organisms (Escherichia coli, Pseudomonas aeruginosa, Streptococcus anginosus group). Sersoal swabs are an effective and practical method of gathering information on organisms. Microbiologic yield was correlated to the severity of appendicitis. Isolation of Streptococcus anginosus increases the incidence of collections to 50%. This is useful to empower surgeons to prognosticate patients' potential outcomes based on both intra-operative, and microbiologic findings, and is useful in counseling patients and managing expectations. A prolonged course of antibiotic agents or higher dose may mitigate this risk.

Differences in isolated bacteria between perforated and non-perforated appendicitis: an analysis of 680 consecutive appendicectomies in a single institution

PURPOSE

Escherichia coli and Bacteroides species are the most frequently detected species in ascites in perforated appendicitis and are generally sensitive to non-empiric cephalosporins like cefazolin or cefmetazole. However, monotherapy with such antibiotics is mostly insufficient for perforated appendicitis. To investigate this issue, this study aimed to compare bacterial floras in ascites culture between perforated and non-perforated appendicitis.

METHODS

Ascites culture results in perforated and non-perforated appendicitis cases were analyzed using a departmental database. The duration of symptoms before surgery, pre-surgical white blood cell count, C-reactive protein value, postsurgical length of stay, length of antibiotic treatment, and the rate of using second-line antibiotics or complications were also compared.

RESULTS

A total of 608 and 72 cases of non-perforated and perforated appendicitis were included. Escherichia coli and Bacteroides species were the dominant bacteria in both conditions. However, the total proportions of Pseudomonas aeruginosa, Streptococcus anginosus group, and Enterococcus group were significantly higher in perforated appendicitis than in non-perforated appendicitis.

CONCLUSION

Pseudomonas aeruginosa, Streptococcus anginosus group, and Enterococcus group have better susceptibility to penicillin-based empiric antibiotics than cephalosporins. The abundance of these bacteria might explain why non-empiric cephalosporins are not effective in perforated appendicitis and the superiority of penicillin-based empiric antibiotics.

Streptococcus anginosus group infections in hospitalised children and young people

AIM

The Streptococcus anginosus group (SAG) comprises three bacterial species colonising the mouth and gastrointestinal and genitourinary tracts and capable of serious pyogenic infections. Although well-described in adults, studies in children are limited. Here, we characterise paediatric SAG infections from a single Australian centre.

METHODS

Hospitalised patients aged ≤18 years with positive SAG cultures from January 2009 to December 2019 were identified from Pathology Queensland's Gold Coast Laboratory database and their medical records were reviewed.

RESULTS

Two-hundred children (62% male), median age 12 years (interquartile range 6-16), with positive SAG cultures were identified. Overall, 90% received intravenous antibiotics, 89% underwent surgical drainage, 23% were readmitted and 15% required additional surgery. The most common sites were the abdomen (39%), soft tissues (36%) and head and neck regions (21%). Since 2011, Pathology Queensland reported SAG at the species level (n = 133). Of these, S. anginosus was the most prevalent (39%), then S. constellatus (34%) and S. intermedius (27%). Compared with the other two species, S. intermedius was most commonly associated with head and neck infections (relative risk (RR) = 2.2, 95% confidence interval (CI) 1.4-3.5), while S. constellatus (RR = 1.7, 95% CI 1.2-2.4) and S. anginosus (RR = 1.5, 95% CI 1.0-2.0) were each associated with a higher risk of intra-abdominal infection than S. intermedius. Since February 2015, the number of children admitted with SAG-associated intra-abdominal infection per 1000 hospitalisations increased by 29% annually compared with an annual decline of 8% in previous years.

CONCLUSIONS

SAG infections occur at various anatomical sites. Despite antibiotics and surgical management, almost one-quarter are re-hospitalised for further treatment.

Clinical, Laboratory and Radiographic Features Associated With Prolonged Hospitalization in Children With Complicated Appendicitis

OBJECTIVE

In children with appendicitis, rupture of the appendix is associated with a significant increase in morbidity. We sought to characterize the spectrum of illness in children with complicated appendicitis and to define those factors associated with a longer hospital stay.

STUDY DESIGN

We conducted a retrospective review of 132 children, 18 years of age or younger at a large urban teaching hospital in the Bronx, NY between October 2015 and April 2018 with an intraoperative diagnosis of perforated appendix. Clinical, laboratory and radiologic findings were reviewed, and the primary study outcome was length of stay (LOS) dichotomized at the median, which was 7 days. Statistical analyses were done to characterize morbidity and define variables predictive of longer stay.

RESULTS

Children in the longer LOS group experienced significantly more morbidity, including ICU stay, ileus, and need for multiple drainage procedures. A longer duration of symptoms prior to presentation was associated with a longer stay. Multivariable logistic regression analysis indicated that the presence of abscess and presence of free fluid in the right upper quadrant (RUQ FF) on initial imaging and C-reactive protein (CRP) level >12 at admission, were independently associated with a longer stay.

CONCLUSION

There is considerable variation in the morbidity of complicated appendicitis. The association between longer stay and the findings of abscess and RUQ FF on initial imaging along with an elevated CRP may provide a useful tool in identifying those children at risk for worse outcomes.

Reduction of surgical site infections in pediatric patients with complicated appendicitis: Utilization of antibiotic stewardship principles and quality improvement methodology

BACKGROUND

The rate of surgical site infection (SSI) after appendectomy for complicated appendicitis (CA) was high at our children's hospital. We hypothesized that practice standardization, including obtaining intra-operative cultures of abdominal fluid in patients with CA, would improve outcomes and reduce healthcare utilization after appendectomy.

METHODS

A quality improvement team designed and implemented a clinical practice guideline for CA that included obtaining intra-operative culture of purulent fluid, administering piperacillin/tazobactam for at least 72 h post-operatively, and transitioning to oral antibiotics based on intraoperative culture data. We compared outcomes before and after guideline implementation.

RESULTS

From July 2018-October 2019, 63 children underwent appendectomy for CA compared to 41 children from January-December 2020. Compliance with our process measures are as follows: Intra-operative culture was obtained in 98% of patients post-implementation; 95% received at least 72 h of piperacillin-tazobactam; and culture results were checked on all patients. Culture results altered the choice of discharge antibiotics in 12 (29%) of patients. All-cause morbidity (SSI, emergency department visit, readmission to hospital, percutaneous drain, unplanned return to operating room) decreased significantly from 35% to 15% (p=0.02). Surgical site infections became less frequent, occurring on average every 27 days pre-implementation and every 60 days after care pathway implementation (p=0.03).

CONCLUSIONS

Utilization of a clinical practice guideline was associated with reduced morbidity after appendectomy for CA. Intra-operative fluid culture during appendectomy for CA appears to facilitate the selection of appropriate post-operative antibiotics and, thus, minimize SSIs and overall morbidity.

The intraperitoneal bacteriology and antimicrobial resistance in acute appendicitis among children: a retrospective cohort study between the years 2007-2017

This study aims to describe the microbiology and susceptibility profile of the intraperitoneal flora in complicated appendicitis. It is a retrospective cohort study including children < 18-year-old with pathologically confirmed appendicitis, from 2007 to 2017. It included 1466 children. Intraperitoneal samples were obtained from 655 (44.7%) patients, and 201 (30.7%) had positive culture with 395 pathogens. Gram-negative rods comprised 67.6%, Gram-positive cocci 21.5%, and anaerobes 10.9% of the isolates. Gram-positive cocci were detected in 67 (37.8%) patients. Milleri group Streptococci was the most frequently isolated Gram-positive (44.7%). The proportional rate of Milleri group Streptococci from Gram-positive cocci increased from 9.5 to 56.3% (P < 0.001, OR 12.214). Patients with Gram-positive cocci had longer hospital stay (mean 9.36 + 6.385 vs 7.72 + 4.582, P = 0.036, (CI -3.165, -0.105)) and more complicated disease (89.5% vs 78.4%, P = 0.045, OR 2.342). Patients with Milleri group Streptococci isolates readmitted more frequently (26.5% vs 13.2%, P = 0.05, OR 2.37). Resistance to amoxicillin-clavulanate, gentamicin, ceftazidime, piperacillin-tazobactam, and amikacin were detected in 29.1%, 6.5%, 2.3%, 1.2%, and 0.7% of the Gram-negative rods, respectively.Conclusion: The rates of Gram-positive cocci and particularly Milleri group Streptococci in peritoneal fluid are increasing. More complicated disease and longer hospital stay in Gram-positive cocci and higher readmission rate in Milleri group Streptococci. These emphasize the role of anti-Gram-positive antimicrobials. What is known: • Gram-negative rods are the main isolates in complicated appendicitis. • The choice of antibiotic regimen is an unsettled issue due to resistance. What is new: • Increased rate of Gram-positive cocci and Milleri group Streptococci. • More complicated disease, longer hospital stay, and higher readmission rate.

Contemporary Microbiology and Antimicrobial Treatment of Complicated Appendicitis: The Value of a Short-term Study

BACKGROUND

Antimicrobial stewardship interventions to curtail the use of third-generation cephalosporins and antipseudomonal penicillins for the treatment of complicated appendicitis in children are challenging given the tendency to treat complicated disease with broad-spectrum antimicrobials. Reasons for this are unclear, but there is a paucity of contemporary microbiologic data associated with the child presenting with either acute perforated or gangrenous appendicitis. This study aimed to justify the appropriateness of an empiric regimen consisting of ampicillin, tobramycin/gentamicin plus metronidazole and to analyze duration of postoperative therapy.

METHODS

We conducted a retrospective cohort study from February 1, 2017, to October 31, 2018, in children who underwent appendectomy or interventional radiologic drainage for primary complicated appendicitis. The primary outcome was the proportion of patients who had a pathogen isolated from peritoneal fluid culture that was not susceptible to the recommended empiric therapy. The secondary outcomes were the total duration of antimicrobial therapy and the proportion of patients with a postoperative infectious complication within 30 days after intervention.

RESULTS

Of 425 children with primary acute appendicitis, 158 (37%) had complicated appendicitis at presentation. Culture was performed in 53 (40%) of the 133 who underwent a surgical or interventional radiologic intervention. The group with peritoneal cultures was more likely to present with longer symptom duration before admission [3 (interquartile range, 2-5) vs 2 (interquartile range, 1-2) days; P < 0.001] and with purulent peritonitis [47% (25/53) vs 13% (10/80); P < 0.001]. The most common pathogens isolated were anaerobes (81%), Escherichia coli (74%) and Streptococcus anginosus group (62%). Only 4% of isolated bacteria were resistant to empiric therapy. Postoperative infectious complications were documented in 23 (17%) patients and were not associated with the presence of a resistant pathogen or the choice of antimicrobial agents but with more severe disease and higher C-reactive protein values (303 vs 83 mg/L; P=0.03) at presentation.

CONCLUSIONS

In a cohort of previously healthy children presenting with complicated appendicitis requiring surgical drainage, the most common bacteria from peritoneal cultures continue to be S. anginosus, aminoglycoside-susceptible Gram-negative bacilli and anaerobes. In an attempt to reduce extended-spectrum cephalosporin use, these data were useful in supporting the use of metronidazole with ampicillin and an aminoglycoside, rather than third-generation cephalosporins.

Intraoperative cultures during appendectomy in children are poor predictors of pathogens and resistance patterns in cultures from postoperative abscesses

BACKGROUND

Intraoperative cultures are commonly sent in complicated appendicitis. Culture-guided antibiotics used to prevent postoperative infectious complications are debated. In this study, we describe the microbial overlap between intraoperative and abscess cultures, and antibiotic resistance patterns.

METHOD

A local register of a children's hospital treating children 0-15 years old with appendicitis between 2006 and 2013 was used to find cases with intraoperative cultures, and cultures from drained or aspirated postoperative intraabdominal abscesses. Culture results, administered antibiotics, their nominal coverage of the identified microorganisms, and rationales given for changes in antibiotic regimens were collected from electronic medical records.

RESULTS

In 25 of 35 patients who met inclusion criteria, there was no overlap between the intraoperative and abscess cultures. In 33 of 35 patients, all identified intraoperative organisms were covered with postoperative antibiotics. In 14 patients, organisms in the abscess culture were not covered by administered antibiotics. Enterococci not found in the intraoperative culture were found in 12 of 35 abscesses. We found no difference in the antibiotic coverage between rationales given for antibiotic changes.

CONCLUSION

The overlap between intraoperative cultures and cultures from subsequent abscesses was small. Lack of antibiotic coverage of intraoperative cultures was not an important factor in abscess formation.