Bacterial culture and antibiotic susceptibility in patients with acute appendicitis

Do Cultures From Percutaneously Drained Intra-abdominal Abscesses Change Treatment? A Retrospective Review

BACKGROUND

Routinely obtaining intraoperative cultures for abdominal infections is not a currently recommended evidence-based practice. Yet, cultures are frequently sent from these infections when they are managed by image-guided percutaneous drains.

OBJECTIVE

This study aimed to determine the utility of cultures from percutaneously drained intra-abdominal abscesses.

DESIGN

Retrospective medical record review.

SETTING

Single university-affiliated institution.

PATIENTS

Inpatients with an intra-abdominal abscess secondary to diverticulitis or appendicitis between 2013 and 2021 managed with image-guided percutaneous drain, excluding those with active chemotherapy, HIV, or solid organ transplant, were included in the study.

MAIN OUTCOME MEASURES

Frequency culture data from percutaneous drains changed antimicrobial therapy.

RESULTS

There were 221 patients who met the inclusion criteria. Of these, 56% were admitted for diverticulitis and 44% for appendicitis. Patients were 54% female and had a median age of 62 years (range, 18-93), and 14% were active smokers. The median length of hospitalization was 8 days (range, 1-78) and the median antibiotics course was 8 days (range, 1-22). Culture data from percutaneous drains altered antimicrobial therapy in 8% of patients (16/211). A culture was obtained from 95% of drains, with 78% of cultures with growth. Cultures grew multiple bacteria in 66% and mixed variety without speciation in 13%. The most common pathogen was the Bacteroides family at 33% of all bacteria. The most common empiric antibiotic regimens were ceftriaxone used in 33% of patients and metronidazole used in 40% of patients. Female sex ( p = 0.027) and presence of bacteria with any antibiotic resistance ( p < 0.01) were associated with higher likelihood of cultures influencing antimicrobial therapy.

LIMITATIONS

Retrospective and single institution's microbiome.

CONCLUSIONS

Microbiology data from image-guided percutaneous drains of abdominal abscesses altered antimicrobial therapy in 8% of patients, which is lower than reported in previously published literature on cultures obtained surgically. Given this low rate, similar to the recommendation regarding cultures obtained intraoperatively, routinely culturing material from drains placed in abdominal abscesses is not recommended. See Video Abstract at http://links.lww.com/DCR/C64 .

LOS CULTIVOS DE ABSCESOS INTRA ABDOMINALES DRENADOS PERCUTNEAMENTE CAMBIAN EL TRATAMIENTO UNA REVISIN RETROSPECTIVA

ANTECEDENTES:La obtención rutinaria de cultivos intra-operatorios para infecciones abdominales no es una práctica basada en evidencia actualmente recomendada. Sin embargo, con frecuencia se envían cultivos de estas infecciones cuando se manejan con drenajes percutáneos guiados por imágenes.OBJETIVO:Determinar la utilidad de los cultivos de abscesos intra-abdominales drenados percutáneamente.DISEÑO:Revisión retrospectiva de gráficos.ESCENARIO:Institución única afiliada a la universidad.PACIENTES:Pacientes hospitalizados con absceso intra-abdominal secundario a diverticulitis o apendicitis entre 2013 y 2021 manejados con drenaje percutáneo guiado por imagen, excluyendo aquellos con quimioterapia activa, VIH o trasplante de órgano sólido.PRINCIPALES MEDIDAS DE RESULTADO:Los datos de cultivo de frecuencia de los drenajes percutáneos cambiaron la terapia antimicrobiana.RESULTADOS:Hubo 221 pacientes que cumplieron con los criterios de inclusión. De estos, el 56% ingresaron por diverticulitis y el 44% por apendicitis. El 54% de los pacientes eran mujeres, tenían una edad media de 62 años (18-93) y el 14% eran fumadores activos. La duración de hospitalización media fue de 8 días (rango, 1-78) y la mediana del curso de antibióticos fue de 8 días (rango, 1-22). Los datos de cultivo de drenajes percutáneos alteraron la terapia antimicrobiana en el 7% (16/221) de los pacientes. Se obtuvo cultivo del 95% de los drenajes, con un 79% de cultivos con crecimiento. Los cultivos produjeron múltiples bacterias en el 63% y variedad mixta sin especiación en el 13%. El patógeno más común fue la familia Bacteroides con un 33% de todas las bacterias. El régimen de antibiótico empírico más común fue ceftriaxona y metronidazol, utilizados en el 33% y el 40% de los pacientes, respectivamente. El sexo femenino ( p = 0,027) y la presencia de bacterias con alguna resistencia a los antibióticos ( p < 0,01) se asociaron con una mayor probabilidad de que los cultivos influyeran en la terapia antimicrobiana.LIMITACIONES:Microbioma retrospectivo y de una sola institución.CONCLUSIONES:Los datos microbiológicos de los drenajes percutáneos guiados por imágenes de los abscesos abdominales alteraron la terapia antimicrobiana en el 7% de los pacientes, que es inferior a la literatura publicada previamente sobre cultivos obtenidos quirúrgicamente. Dada esta baja tasa, similar a la recomendación sobre cultivos obtenidos intraoperatoriamente, no se recomienda el cultivo rutinario de material de drenajes colocados en abscesos abdominales. Consulte Video Resumen en http://links.lww.com/DCR/C64 . (Traducción-Dr. Mauricio Santamaria.

Perioperative Antibiotics in Appendicitis-Do We Need to Adjust Therapy for the Elderly? A Matched Pair Analysis

(1) Background: Perioperative Antibiotics for acute complicated appendicitis are a standard of care. While there are plenty of trials for pediatric patients, data for elderly patients are scarce. The goal of our study was to evaluate whether elderly patients carry more resistant bacteria and thus have less favorable outcomes after an appendectomy that may warrant intensified perioperative antibiotic treatment (2) We present a retrospective single-center matched pair (139 patients each) analysis of perioperative and microbiological outcomes of an elderly appendicitis cohort (i.e., older than 60 years) compared with a younger adult cohort (i.e., ≤60 years). Both groups were matched one for one according to gender, duration of symptoms, c-reactive protein at presentation and whether they presented with uncomplicated or complicated appendicitis. (3) Results: After matching, complicated appendicitis was present in 76.3% of both groups. Elderly patients more frequently received preoperative diagnostic CT (p < 0.001) than the young. Both operative strategy (laparoscopic appendectomy in 92.1% each) and duration of surgery (57 vs. 56 min) were equal in both groups. Postoperative antibiotics were prescribed in ~57% for a median of 3 days in both groups and antibiotic selection was similar. The incidence of surgical site infections was higher in the young (12.2% vs. 7.9%) yet not significant. There was no difference in culture positivity or bacterial spectrum and the elderly cohort did not present with increased resistant bacterial isolates. (4) Conclusions: While overall resistant bacterial strains were rare, perioperative outcomes between the young and the elderly did not differ and did neither warrant longer nor intensified antibiotic treatment.

Characteristics of appendicitis after immune checkpoint inhibitor therapy among cancer patients

PURPOSE

Immune checkpoint inhibitor (ICI) therapy has revolutionized cancer care but is associated with immune-related adverse events (irAEs). Recent case reports raised the concern that acute appendicitis may be an irAE. In this study, we sought to describe the disease course of post-ICI therapy appendicitis and its associated complications.

METHODS

Adult patients who had an International Classification of Diseases code for appendicitis within the first 2 years after initiating ICI therapy from January 2010 to April 2021 and who had imaging evidence of appendicitis were studied retrospectively.

RESULTS

13,991 patients were identified who had ICI exposure during the study period, 44 had codes for appendicitis, 10 of whom met the inclusion criteria. Their median age at the time of diagnosis was 59 years. The median time from ICI therapy initiation to appendicitis onset was 188 days. The most common presenting symptoms were abdominal pain (70%) and fever (40%). Abscesses were present in two patients, and a perforation was present in one. All 10 patients received broad-spectrum antibiotics. Five patients needed surgery or interventional radiology drainage. Nine patients had resolution of appendicitis symptoms after treatment.

CONCLUSION

Post-ICI therapy appendicitis is rare but presents similarly to and has similar complications rates as conventional appendicitis. Appendectomy remains the mainstay of treatment, but its use can be limited in cancer patients. The decision to continue ICI therapy remains at the discretion of the clinician. Further studies are needed to bring awareness to and advance the understanding of this clinical entity.

Blood culture positivity in patients with acute appendicitis: A propensity score-matched prospective cohort study

BACKGROUND AND OBJECTIVE

The prevalence of bacteremia in acute appendicitis is unknown. We aimed to assess prevalence and predictive factors of bacteremia in adult patients with appendicitis.

METHODS

In this prospective propensity score-matched cohort study, patients were recruited as part of one single-center prospective observational study assessing appendicitis microbiology in concurrence with two randomized controlled trials on non-operative treatment of uncomplicated acute appendicitis. All patients evaluated for enrollment in these three trials between April 2017 and December 2018 with both a confirmed diagnosis of appendicitis and available blood culture on admission were included in this study. Potential predictive factors of bacteremia (age, sex, body mass index (BMI), body temperature, C-reactive protein (CRP), leukocyte count, comorbidities, symptom duration, and appendicitis severity) were assessed. Prevalence of bacteremia was determined by all available blood cultures followed by propensity score matching using sex, age, BMI, CRP, leukocyte count, and body temperature of the patients without available blood culture.

RESULTS

Out of the 815 patients with appendicitis, 271 patients had available blood culture and the prevalence of bacteremia was 12% (n = 33). Based on propensity score estimation, the prevalence of bacteremia in the whole prospective appendicitis cohort was 11.1%. Bacteremia was significantly more frequent in complicated acute appendicitis (15%; 29/189) compared with uncomplicated acute appendicitis (5%; 4/82) (p = 0.015). Male sex (p = 0.024) and higher body temperature (p = 0.0044) were associated with bacteremia.

CONCLUSIONS

Estimated prevalence of bacteremia in patients with acute appendicitis was 11.1%. Complicated appendicitis, male sex, and higher body temperature were associated with bacteremia in acute appendicitis.

Microbiota Assessment of Pediatric Simple and Complex Acute Appendicitis

Background and Objectives. The aim of this study is to determine the prevailing microbiota in samples from pediatric patients with acute appendicitis, as well as evaluate the antibacterial sensitivity of the isolated microorganisms, comparing the data obtained with the clinic’s antibacterial therapy guidelines. Materials and Methods. The study group consisted of 93 patients between the ages of 7 and 18. All patients underwent a laparoscopic or conventional appendectomy. The children were hospitalized with signs and symptoms suggestive of acute appendicitis. Microbiological cultures from the appendix and abdominal cavity were collected intraoperatively. Results. E. coli was identified in most cases irrespective of the clinical presentation of acute appendicitis. Most strains were susceptible to ampicillin and amoxicillin/clavulanic acid. Five strains of E. coli produced extended spectrum beta-lactamase (ESBL). Pseudomonas aeruginosa (P. aeruginosa) was the second most commonly isolated causative agent. Furthermore, it was common in cases of acute complex appendicitis. Most strains of P. aeruginosa were resistant to amoxicillin/clavulanic acid, ertapenem, ampicillin and cefotaxime, yet were susceptible to ceftazidime. Regardless of the clinical presentation, the samples yielded mixed isolates. Conclusion. E. coli is the main causative agent of acute appendicitis in the pediatric population displaying susceptibility to various antibiotics. P. aeruginosa was more prevalent in cases of acute complex appendicitis. P. aeruginosa isolates were susceptible to ceftazidime; however, they were resistant to cefotaxime, which should, therefore, be removed from guidelines for empirical antibacterial treatment of acute appendicitis due to phenotypic resistance of P. aeruginosa. We recommend antibiotics with distinct implementation to avoid antibiotic resistance.

Is Routine Intra-operative Gram Stain, Culture, and Sensitivity during an Appendectomy is Effective in Decreasing the Rate of Post-operative Infective Complications?

BACKGROUND: Organisms blamed in acute appendicitis are right predictable and very susceptible to a wide range of broad-spectrum antibiotics. AIM: The aim of the study was to assess the clinical benefit of the routine intra-operative swab during an appendectomy in guiding antibiotic selection. METHODS: Four hundred and thirty patients underwent appendectomy halved into two groups, each 215. In Group 1, an intra-operative swab was routinely obtained for culture/sensitivity. The results of which were reviewed for helping direct antibiotic selection. No intra-operative swabs were obtained in Group 2. Both groups were given single-dose cefotaxime and metronidazole preoperatively intravenously at the time of induction of anesthesia. RESULTS: In swab group, 63/215 cultures (29.3%) revealed pathogens, while (70.7%) were negative or revealed isolated colonic commensals. Most cultures were negative or isolated colonic commensals. Fifty-two/63 cultures (82.54%) were sensitive to both cefotaxime and metronidazole, and only 11/63 (17.46%) reported resistant organisms to cefotaxime but not to metronidazole. Most pathogens were sensitive to empirical antibiotics. Twenty-two/215 patients (10.23%) developed infective complications, most (63.6%) had their cultures from the infected wound yielded different micro-organisms. Only 8/215 (3.72%) in the swab group needed a change in the empirical antibiotics for treating infective complications. In the non-swab group, 19/215 patients (8.83%) developed infective complications. Only 6/215 patients (2.8%) needed a change in the empirical antibiotics for treating infective complications. Collectively, only 14/430 patients (3.25%) required a change in the empirical antibiotics for treating infected wounds. CONCLUSIONS: Routine peritoneal swabs for culture/sensitivity during appendicectomy are of no clinical value. Such practice is considered a waste of laboratory resources and money. A single prophylactic dose of antibiotics has significant role in preventing surgical site infection.

Characterization of bacterial community structure dynamics in a rat burn wound model using 16S rRNA gene sequencing

Burns destroy the skin barrier and alter the resident bacterial community, thereby facilitating bacterial infection. To treat a wound infection, it is necessary to understand the changes in the wound bacterial community structure. However, traditional bacterial cultures allow the identification of only readily growing or purposely cultured bacterial species and lack the capacity to detect changes in the bacterial community. In this study, 16S rRNA gene sequencing was used to detect alterations in the bacterial community structure in deep partial-thickness burn wounds on the back of Sprague-Dawley rats. These results were then compared with those obtained from the bacterial culture. Bacterial samples were collected prior to wounding and 1, 7, 14, and 21 days after wounding. The 16S rRNA gene sequence analysis showed that the number of resident bacterial species decreased after the burn. Both resident bacterial richness and diversity, which were significantly reduced after the burn, recovered following wound healing. The dominant resident strains also changed, but the inhibition of bacterial community structure was in a non-volatile equilibrium state, even in the early stage after healing. Furthermore, the correlation between wound and environmental bacteria increased with the occurrence of burns. Hence, the 16S rRNA gene sequence analysis reflected the bacterial condition of the wounds better than the bacterial culture. 16S rRNA sequencing in the Sprague-Dawley rat burn model can provide more information for the prevention and treatment of burn infections in clinical settings and promote further development in this field.

Optimal initial antibiotic regimen for the treatment of acute appendicitis: a systematic review and network meta-analysis with surgical intervention as the common comparator

BACKGROUND

The optimal antibiotic regimen for the medical management of acute appendicitis remains unknown due to a lack of head-to-head comparisons between different antibiotic regimens.

METHODS

We systematically searched the PubMed, EMBASE, Scopus and Cochrane Central Register of Controlled Trials databases from their inception through to August 2020. We selected randomized controlled trials (RCTs) or observational studies comparing antibiotic therapy and appendectomy as the initial treatment for adult or paediatric patients with acute appendicitis. We performed a Bayesian network meta-analysis (NMA) to obtain the indirect comparison results between different antibiotic regimens by employing the group managed by surgery as a common comparator. Antibiotic regimens were classified into three categories: those including a carbapenem; those including a cephalosporin; and those including a β-lactam/β-lactamase inhibitor combination.

RESULTS

A total of 9 RCTs (adults, n = 8; paediatrics, n = 1) and 12 observational studies (adults, n = 3; paediatrics, n = 9) were included in the NMA, with a total of 4551 patients. The most commonly administered regimen was a β-lactam/β-lactamase inhibitor combination (9/21; 43%), followed by a cephalosporin (7/21; 33%) or a carbapenem (5/21; 24%). The NMA indicated that surgery significantly increased 1 year treatment success, compared with cephalosporins [OR: 16.79; 95% credible interval: 3.8-127.64] or β-lactam/β-lactamase inhibitor combinations (OR: 19.99; 95% credible interval: 4.87-187.57), but not carbapenems (OR: 3.50, 95% credible interval: 0.55-38.63). In contrast, carbapenems were associated with fewer treatment-related complications compared with surgery (OR: 0.12; 95% credible interval: 0.01-0.85).

CONCLUSIONS

Carbapenems might be recommended as the initial antibiotic regimen for the non-operative management of adult patients with acute appendicitis. Nevertheless, due to the imprecise estimates in our NMA, additional RCTs are needed to corroborate these findings, especially for paediatric patients.

Antimicrobial Resistance in Escherichia coli Strains Isolated from Humans and Pet Animals

Throughout scientific literature, we can find evidence that antimicrobial resistance has become a big problem in the recent years on a global scale. Public healthcare systems all over the world are faced with a great challenge in this respect. Obviously, there are many bacteria that can cause infections in humans and animals alike, but somehow it seems that the greatest threat nowadays comes from the Enterobacteriaceae members, especially Escherichia coli. Namely, we are witnesses to the fact that the systems that these bacteria developed to fight off antibiotics are the strongest and most diverse in Enterobacteriaceae. Our great advantage is in understanding the systems that bacteria developed to fight off antibiotics, so these can help us understand the connection between these microorganisms and the occurrence of antibiotic-resistance both in humans and their pets. Furthermore, unfavorable conditions related to the ease of E. coli transmission via the fecal-oral route among humans, environmental sources, and animals only add to the problem. For all the above stated reasons, it is evident that the epidemiology of E. coli strains and resistance mechanisms they have developed over time are extremely significant topics and all scientific findings in this area will be of vital importance in the fight against infections caused by these bacteria.

Usefulness of intraoperative culture swabs in laparoscopic appendectomy for complicated appendicitis

PURPOSE

Intraabdominal abscess (IAA) is a feared complication after laparoscopic appendectomy (LA) for complicated appendicitis. Benefits of obtaining intraoperative culture swabs (ICS) still remain controversial. We aimed to determine whether ICS modify the rate and management of IAA after LA for complicated appendicitis.

METHODS

A consecutive series of patients who underwent LA for complicated appendicitis from 2008 to 2018 were included. The cohort was divided into two groups: group 1 (G1), with ICS, and group 2 (G2), without ICS. Demographics, operative variables, pathogen isolation, antibiotic sensitivity, and postoperative outcomes were analyzed.

RESULTS

A total of 1639 LA were performed in the study period. Of these, 270 (16.5%) were complicated appendicitis; 90 (33%) belonged to G1 and 180 (67%) to G2. In G1, a higher proportion of patients had generalized peritonitis (G1, 63.3%; G2, 35%; p < 0.01). Seventy-two (80%) patients had positive cultures in G1. The most frequently isolated bacteria were E. coli (66.7%), Bacteroides spp. (34.7%), and Streptococcus spp. (19.4%). In 26 (36%) patients, the initial empiric antibiotic course was modified due to bacterial resistance. The rate of IAA was higher in patients with ICS (G1, 21.1%; G2, 9.4%; p = 0.01). IAA was treated similarly in both groups. A different type of bacteria was isolated in 7 (53.8%) patients with new culture swabs.

CONCLUSIONS

Obtaining ICS in LA for complicated appendicitis with further antibiotic adjustment to the initial pathogen did not lower the incidence of postoperative IAA and did not modify the treatment needed for this complication.

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

Introducción.

La apendicitis aguda es la primera causa de abdomen agudo; sin embargo, poco se conoce sobre las bacterias asociadas y su perfil de sensibilidad.

Objetivo.

Identificar y determinar el patrón de resistencia de las bacterias aerobias y anaerobias aisladas en cultivo de líquido periapendicular tomado de los pacientes con apendicitis aguda, y establecer la proporción de bacterias según la fase clínica.

Materiales y métodos.

Se llevó a cabo un estudio descriptivo y prospectivo en el Hospital Universitario de San José de Bogotá (Colombia), en pacientes mayores de 16 años sometidos a apendicectomía abierta. Se tomaron muestras de líquido periapendicular, las cuales se sembraron directamente en botellas de hemocultivos para aerobios y anaerobios.

Resultados.

Se incluyeron 154 pacientes. Del total de cultivos, el 87 % (n=134) fueron positivos: 77 % (n=118) para aerobios y 51 % (n=79) para anaerobios. La proporción de cultivos positivos fue inferior en los casos de apendicitis no complicada, en comparación con aquellos de apendicitis complicada (80 % (66/83) Vs. 95 % (67/71); p=0,003). Los microorganismos aislados con mayor frecuencia fueron: Escherichia coli (53 %) (n=84), Bacteroides sp. (25 %) (n=25), Propionibacterium acnes (21 %) (n=21), Staphylococci coagulasa negativo (17 %) (n=27), Enterococcus sp. (10 %) (n=15) y Fusobacterium sp. (11 %) (n=11). La sensibilidad de E. coli a la amplicilina sulbactam fue de 30 %. La sensibilidad de Bacteroides spp. a la clindamicina y la ampicilina sulbactam fue de 91 %. El 100 % de los anaerobios fueron sensibles a piperacilina tazobactam, ertapenem, meropenem y metronidazol.

Conclusiones.

Los cultivos intraoperatorios son pertinentes en la apendicitis para determinar el patrón epidemiológico local, y establecer los antibióticos profilácticos y terapéuticos para esta enfermedad. Su siembra directa en botellas de hemocultivo permite una gran recuperación de microorganismos.

Increased risk of appendectomy in patients with asthma: A nested case-control study using a national sample cohort

The study aimed to expand previous data regarding an association between asthma and appendectomy in children compared with the population of all ages.The Korean Health Insurance Review and Assessment Service-National Sample Cohort from 2002 through 2013 was used. In all, 22,030 participants who underwent appendectomy were matched for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia with 88,120 participants who were included as a control group. In both the appendectomy and control groups, previous history of asthma was investigated. Appendectomy for appendicitis was identified based on a surgical code (International Classification of Disease-10 [ICD-10]: K35). Asthma was classified using an ICD-10 code (J45 and J46) and medication history. The crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of asthma for appendectomy were analyzed using conditional logistic regression analysis. Subgroup analyses were conducted according to age and sex.Approximately 15.2% (3358/22,030) of individuals in the appendectomy group and 13.3% (11,749/88,120) of those in the control group had asthma (P < .001). The appendectomy group demonstrated a higher adjusted odds of asthma than the control group (adjusted OR 1.18, 95% CI 1.13-1.23, P < .001). This result was consistent in the subgroups divided according to age and sex.The odds for asthma were higher in the appendectomy group than in the control group.

Risk factors for additional port insertion in single-port laparoscopic appendectomy

Introduction

Single-port laparoscopic appendectomy (SPLA) was expected to have reduced risk of wound infection, less postoperative pain, and improved patient’s satisfaction with better cosmesis compared with conventional laparoscopic appendectomy (CLA). When SPLA is converted to CLA, the additional incision for another port insertion can lead to a decrease in the surgical advantages and clinical benefit.

Aim

To evaluate risk factors for conversion to CLA during SPLA.

Material and methods

Between August 2015 and December 2016, patients who underwent intended SPLA were retrospectively reviewed. Conversion was defined as any insertion of an additional port, and complicated appendicitis was defined as gangrenous or perforated appendicitis, abscess, or peritonitis in preoperative computed tomography. Postoperative complication was defined as any deviation in the routine postoperative course within 30 days postoperatively.

Results

Of 409 patients, 65 (15.9%) were treated with additional port insertion. The overall complication rate was 1.5% in each group, of which 1 patient developed superficial SSI and 4 patients developed deep surgical site infections in the SPLA group. After univariable and multivariable analysis, old age, male sex, increased serum C-reactive protein (OR = 2.944; 95% CI: 1.433–6.047; p = 0.003), and complicated appendicitis (OR = 3.330; 95% CI: 1.304–8.503; p = 0.012) were significant risk factors for conversion to CLA.

Conclusions

The conversion rate to CLA was 15.9%. Serum C-reactive protein level and complicated appendicitis were strong predictive factors for conversion from SPLA in acute appendicitis.