Recovery of aerobic and anaerobic bacteria from patients with acute appendicitis using blood culture bottles

Bacterial pathogens in pediatric appendicitis: a comprehensive retrospective study

Background

Appendicitis is a frequent condition, with peak incidences in the second decade of life. Its pathogenesis is under debate, but bacterial infections are crucial, and antibiotic treatment remains essential. Rare bacteria are accused of causing complications, and various calculated antibiotics are propagated, yet there is no comprehensive microbiological analysis of pediatric appendicitis. Here we review different pre-analytic pathways, identify rare and common bacterial pathogens and their antibiotic resistances, correlate clinical courses, and evaluate standard calculated antibiotics in a large pediatric cohort.

Method

We reviewed 579 patient records and microbiological results of intraoperative swabs in standard Amies agar media or fluid samples after appendectomies for appendicitis between May 2011 and April 2019. Bacteria were cultured and identified via VITEK 2 or MALDI-TOF MS. Minimal inhibitory concentrations were reevaluated according to EUCAST 2022. Results were correlated to clinical courses.

Results

Of 579 analyzed patients, in 372 patients we got 1330 bacterial growths with resistograms. 1259 times, bacteria could be identified to species level. 102 different bacteria could be cultivated. 49% of catarrhal and 52% of phlegmonous appendices resulted in bacterial growth. In gangrenous appendicitis, only 38% remained sterile, while this number reduced to 4% after perforation. Many fluid samples remained sterile even when unsterile swabs had been taken simultaneously. 40 common enteral genera were responsible for 76.5% of bacterial identifications in 96.8% of patients. However, 69 rare bacteria were found in 187 patients without specifically elevated risk for complications.

Conclusion

Amies agar gel swabs performed superior to fluid samples and should be a standard in appendectomies. Even catarrhal appendices were only sterile in 51%, which is interesting in view of a possible viral cause. According to our resistograms, the best in vitro antibiotic was imipenem with 88.4% susceptible strains, followed by piperacillin-tazobactam, cefuroxime with metronidazole, and ampicillin-sulbactam to which only 21.6% of bacteria were susceptible. Bacterial growths and higher resistances correlate to an elevated risk of complications. Rare bacteria are found in many patients, but there is no specific consequence regarding antibiotic susceptibility, clinical course, or complications. Prospective, comprehensive studies are needed to further elicit pediatric appendicitis microbiology and antibiotic treatment.

Bloodstream infections and antibiotic resistance at a regional hospital, Colombia, 2019-2021

Objectives

To assess antibiotic susceptibility of World Health Organization (WHO) priority bacteria (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Salmonella spp., Staphylococcus aureus, and Streptococcus pneumoniae) in blood cultures at the Orinoquía regional hospital in Colombia.

Methods

This was cross-sectional study using routine laboratory data for the period 2019-2021. Data on blood samples from patients suspected of a bloodstream infection were examined. We determined: the total number of blood cultures done and the proportion with culture yield; the characteristics of patients with priority bacteria; and the type of bacteria isolated and antibiotic resistance patterns.

Results

Of 25 469 blood cultures done, 1628 (6%) yielded bacteria; 774 (48%) of these bacteria were WHO priority pathogens. Most of the priority bacteria isolated (558; 72%) were gram-negative and 216 (28%) were gram-positive organisms. Most patients with priority bacteria (666; 86%) were hospitalized in wards other than the intensive care unit, 427 (55%) were male, and 321 (42%) were ≥ 60 years of age. Of the 216 gram-positive bacteria isolated, 205 (95%) were Staphylococcus aureus. Of the 558 gram-negative priority bacteria isolated, the three most common were Escherichia coli (34%), Klebsiella pneumoniae (28%), and Acinetobacter baumannii (20%). The highest resistance of Staphylococcus aureus was to oxacillin (41%). For gram-negative bacteria, resistance to antibiotics ranged from 4% (amikacin) to 72% (ampicillin).

Conclusions

Bacterial yield from blood cultures was low and could be improved. WHO priority bacteria were found in all hospital wards. This calls for rigorous infection prevention and control standards and continued surveillance of antibiotic resistance.

Effectiveness of Five Antibiotic Regimens for the Treatment of Intra-Abdominal Infection in Bogotá

Background: Intra-abdominal infection (IAI) results in prolonged in-hospital length-of-stay, critical care unit requirements, and multiple surgical procedures. Several antimicrobial agents are available for treatment of IAI. In Colombia, there are no data on the comparative effectiveness of the different regimens used. Patients and Methods: A multicenter retrospective cohort study was completed in four third-level hospitals by comparing treatment effectiveness of five different antibiotic protocols (ampicillin-sulbactam, clindamycin-amikacin, piperacillin-tazobactam, amikacin-metronidazole, and cefuroxime-metronidazole) in patients with a diagnosis of IAI. Analysis was based on a composed outcome of therapeutic failure (change of antibiotic because of no clinical improvement, requirement of surgical re-intervention, post-operative infection, change of antibiotic because of antimicrobial resistance, and in-hospital mortality). Association of each antibiotic protocol to therapeutic failure was assessed through logistic regression analysis. Results: Five hundred ninety-three individuals were included. Two hundred twenty-nine were prescribed ampicillin-sulbactam; 170, clindamycin-amikacin; 77, amikacin-metronidazole; 83, piperacillin-tazobactam; and 34, cefuroxime-metronidazole. Therapeutic failure rate was 22%. Multivariable analysis showed none of the evaluated antibiotic protocols had an association with the primary outcome. Variables having an association for higher risk were age >70 years old (odds ratio [OR], 2.08; 95% confidence interval [CI], 1.04-4.18); complicated IAI (OR, 3.36; 95% CI, 1.4-8.07); and World Society of Emergency Surgery (WSES) Sepsis Severity Score (OR, 1.31; 95% CI, 1.18-1.45). Adequate source control (OR, 0.16; 95% CI, 0.05-0.45) and hospitalization at Health Center 2 (OR, 0.30; 95% CI, 0.14-0.63) were identified as protective factors. Conclusions: There are no differences between the rate of therapeutic failure among the different antibiotic protocols evaluated. This outcome depends heavily on risk factors related to disease severity when surgical intervention occurs.

Risk Factors of Recurrent Appendiceal Abscess after Initial Non-Surgical Treatment without Drainage of Children with Appendiceal Abscess: A Single Center Retrospective Review

Background: Exploration of the risk factors of recurrent appendiceal abscess after initial non-surgical treatment without drainage in children with appendiceal abscess. Patients and Methods: The medical records of all children diagnosed with appendiceal abscess and who were treated conservatively in the Children's Hospital of Chongqing Medical University from June 2012 to June 2020 were collected. The collected cases were divided into the recurrent group and the non-recurrent group, and all clinical indicators were compared. Logistic regression analysis was used to determine the risk factors for recurrent appendiceal abscess in children. Results: One hundred twenty-four patients were included and among them, 62 (50.0%) had clinical manifestations of recurrent appendiceal abscess (the recurrent group) and five patients (8%) suffered several instances of recurrence. Duration of intravenous antibiotic agents (odds ratio [OR], 0.905; 95% confidence interval [CI], 0.820-1.000) was independently associated with the recurrence of appendiceal abscess. The risk of recurrence was increased in children with the white blood cell (WBC) count at discharge greater than 8 × 10⁹/L (OR, 2.702; 95% CI,1.172-6.231), the ratio of mass size to body surface area (BSA) at discharge greater than 4.255 (OR, 1.369; 95% CI, 1.104-1.697), and without continuous oral antibiotic agents after discharge (OR, 3.111; 95% CI, 1.240-7. 802). Conclusions: Interval appendectomy is recommended for children with WBC count at discharge greater than 8 × 10⁹/L, and the ratio of mass size to BSA at discharge greater than 4.255, because they are more likely to develop recurrent appendiceal abscess after initial conservative treatment. The duration of intravenous antibiotic agents is an independent factor of the recurrence of appendiceal abscess, and a longer course of intravenous antibiotic agents is strongly associated with a reduced risk of recurrence. Continued oral antibiotic agents after discharge can effectively reduce the risk of recurrence of appendiceal abscesses.

Seasonal Variation and Severity of Acute Abdomen in Japan: A Nine-Year Retrospective Analysis

The seasonal incidence of acute abdomens, such as appendicitis, is reportedly more common in summer but is reported less frequently in Asia. Additionally, seasonal variations in the severity of acute abdomens have been evaluated insufficiently. This study evaluated the seasonal variations in the incidence and severity of acute abdomens in Japan. This retrospective observational study used a multicenter database containing data from 42 acute hospitals in Japan. We included all patients diagnosed with acute appendicitis, diverticulitis, cholecystitis, and cholangitis between January 2011 and December 2019. Baseline patient data included admission date, sequential organ failure assessment score, presence of sepsis, and disseminated intravascular coagulation. We enrolled 24,708 patients with acute abdomen. Seasonal admissions for all four acute abdominal diseases were the highest in summer [acute appendicitis, (OR = 1.35; 95% CI = 1.28-1.43); diverticulitis, (OR = 1.23; 95% CI = 1.16-1.31; cholecystitis (OR = 1.23; 95% CI = 1.11-1.36); and cholangitis (OR = 1.23; 95% CI = 1.12-1.36)]. The proportion of patients with sepsis and disseminated intravascular coagulation as well as the total SOFA score for each disease, did not differ significantly across seasons. Seasonal variations in disease severity were not observed.

Emphysematous Cholecystitis Secondary to Fusobacterium nucleatum

Fusobacterium nucleatum may be implicated in cases of emphysematous cholecystitis (EC) and carries a high mortality risk, especially in individuals with heart disease, renal insufficiency, and underlying malignancy. Fusobacterium infections are rarely detected in the setting of cholecystitis possibly due to the difficulty with properly culturing the bacteria. We describe a case of a patient with EC in whom blood cultures were positive for growth of F. nucleatum in one of two samples. The patient was treated with empiric antibiotic therapy consisting of metronidazole and cefepime. In patients with EC and negative cultures, it is possible that they may have an undetected infection with fusobacteria, which carries a high mortality risk. As such, clinicians should maintain a high degree of suspicion of obligate anaerobic infection in patients who have negative blood culture for growth in the setting of EC and consider continuation of adequate antimicrobial coverage.