The bacteriology of gangrenous and perforated appendicitis--revisited

The first case of Odoribacter splanchnicus bacteremia isolated from a patient in China

Background

Odoribacter splanchnicus is an extremely rare pathogen of human infection. This case reports bacteremia infection of O. splanchnicus, which is highly likely to result in misdiagnosis if inappropriate diagnostic method are used.

Case presentation

A 29-year-old Chinese male patient with no underlying disease was hospitalized twice for injuries caused by a car accident. During the second hospitalization, abdominal surgery was performed and high fever developed after the surgery. A strain of O. splanchnicus was isolated from the blood and confirmed by MALDI-TOF-MS and 16S rRNA gene analysis. Finally, the patient recovered successfully by using antibiotics, fluid replacement and albumin input.

Conclusions

This is the first case of O. splanchnicus bacteremia in China. We present a brief review of the cases concerning O. splanchnicus infection in humans. O. splanchnicus, as part of the normal intestinal flora, is well known for its anti-tumor and immune regulating properties, it is rarely isolated from clinical samples. This case illustrates the potential of O. splanchnicus as a pathogen and suggests attention to the use of new and advanced methods like MALDI-TOF MS and 16S rRNA gene sequencing to identify rarely isolated species from clinical samples.

Elevated total and direct bilirubin are associated with acute complicated appendicitis: a single-center based study in Saudi Arabia

BACKGROUND

Appendicitis is the most common abdominal surgical emergency and up to our knowledge no previous studies have been conducted in Saudi Arabia particularly at Qassim region and this study aimed to determine a total and direct bilirubin as a predictor of acute complicated appendicitis.

METHODS

Observational retrospective study that included patients admitted under the general surgery department with a diagnosis of acute appendicitis at King Saud Hospital, Unaizah, Saudi Arabia. Data on age, gender, BMI, diabetes mellitus, total and direct bilirubin, AST, ALT, sodium, and WBCs levels were obtained.

RESULT

Among the overall study population of 158 patients, the age median [IQR] was 24.5 [19-31], males were 99 (62.7%), and complicated appendicitis was 33 (20.9%). The multivariable analysis revealed that both elevated total and direct bilirubin are associated with complicated appendicitis (aOR = 3.79, 95% CI: 1.67-8.48, P = 0.001) and (aOR = 4.74, 95% CI: 2.07-10.86, P < 0.001) respectively. A receiver operating characteristic curve showed the best cutoff value of total and direct bilirubin as ≥ 15 µmol/L and ≥ 5 µmol/L respectively, with a sensitivity of 57.6%, and specificity of 73.6% for elevated total bilirubin, and a sensitivity of 54.6%, and specificity of 80% for elevated direct bilirubin.

CONCLUSION

Elevated total and direct bilirubin are associated with acute complicated appendicitis in this setting. However, it should be supportive factor for acute complicated appendicitis and not considered as standalone diagnostic test.

Role of immature granulocytes and total bilirubin values in the diagnosis of perforated appendicitis in patients over 65 years

OBJECTIVE

The aim of this study was to investigate the effectiveness of immature granulocyte count, immature granulocyte percentage, and total bilirubin value in predicting complicated and perforated appendicitis in patients aged 65 years and older with a diagnosis of appendicitis.

METHODS

In this study, 84 patients, aged 65 years and older, who had appendectomy demographic information, preoperative white blood cell count, neutrophil/lymphocyte ratio, immature granulocyte count and immature granulocyte percentage, operation findings, and pathology results were collected retrospectively. They were grouped into 4 categories: complicated, non-complicated, perforated, and non-perforated, according to the data and surgical findings.

RESULTS

Total bilirubin and immature granulocyte count were found to be statistically significant in predicting complicated and perforated appendicitis in patients aged 65 years and older with a diagnosis of appendicitis. The total bilirubin was found to have the following values in differentiating complicated appendicitis: area under the curve=0.883, sensitivity=78.3%, and specificity=88.5%. Total bilirubin had the highest discrimination power with area under the curve=0.804 in differentiating perforation.

CONCLUSION

The immature granulocyte percentage and total bilirubin count are the fast, inexpensive, and reliable parameters that can be used to predict complicated and perforated appendicitis in patients aged 65 years and older.

Implications of bacteriological study in complicated and uncomplicated acute appendicitis

Purpose

Bacteriological sample in the presence of intraabdominal free fluid is necessary to adapt the antibiotherapy and to prevent the development of resistance. The aim was to evaluate the differences between uncomplicated (UAA) and complicated acute appendicitis (CAA) in terms of bacterial culture results and antibiotic resistance, and to evaluate the factors linked with CAA.

Methods

We performed a single-center, retrospective observational study of all consecutive patients who presented with appendicular peritonitis and underwent emergent surgery in a tertiary referral hospital in Brussels, Belgium, between January 2013 and December 2020. The medical history, parameters at admission, bacterial culture, antibiotic resistance, and postoperative outcomes of 268 patients were analyzed. UAA was considered catarrhal or phlegmonous inflammation of the appendix. CAA was considered gangrenous or perforated appendicitis.

Results

Positive microbiological cultures were significantly higher in the CAA group (68.2% vs. 53.4%). The most frequently isolated bacteria in UAA and CAA cultures were Escherichia coli (37.9% and 48.6%). Most observed resistances were against ampicillin (28.9% and 21.7%) and amoxicillin/clavulanic acid (16.4% and 10.5%) in UAA and CAA, respectively. A higher Charlson comorbidity index, an elevated white blood cell count, an open procedure, and the need for drainage were linked to CAA. Culture results, group of bacterial isolation, and most common isolated bacteria were not related to CAA.

Conclusion

CAA presented a higher rate of positive cultures with increased identification of gram-negative bacteria. Bacterial culture from the peritoneal liquid does not reveal relevant differences in terms of antibiotic resistance.

Bacteroidales species in the human gut are a reservoir of antibiotic resistance genes regulated by invertible promoters

Antibiotic-resistance genes (ARGs) regulated by invertible promoters can mitigate the fitness cost of maintaining ARGs in the absence of antibiotics and could potentially prolong the persistence of ARGs in bacterial populations. However, the origin, prevalence, and distribution of these ARGs regulated by invertible promoters remains poorly understood. Here, we sought to assess the threat posed by ARGs regulated by invertible promoters by systematically searching for ARGs regulated by invertible promoters in the human gut microbiome and examining their origin, prevalence, and distribution. Through metagenomic assembly of 2227 human gut metagenomes and genomic analysis of the Unified Human Gastrointestinal Genome (UHGG) collection, we identified ARGs regulated by invertible promoters and categorized them into three classes based on the invertase-regulating phase variation. In the human gut microbiome, ARGs regulated by invertible promoters are exclusively found in Bacteroidales species. Through genomic analysis, we observed that ARGs regulated by invertible promoters have convergently originated from ARG insertions into glycan-synthesis loci that were regulated by invertible promoters at least three times. Moreover, all three classes of invertible promoters regulating ARGs are located within integrative conjugative elements (ICEs). Therefore, horizontal transfer via ICEs could explain the wide taxonomic distribution of ARGs regulated by invertible promoters. Overall, these findings reveal that glycan-synthesis loci regulated by invertible promoters in Bacteroidales species are an important hotspot for the emergence of clinically-relevant ARGs regulated by invertible promoters.

Diagnosis and Management of Acute Appendicitis in Adults: A Review

IMPORTANCE

Acute appendicitis is the most common abdominal surgical emergency in the world, with an annual incidence of 96.5 to 100 cases per 100 000 adults.

OBSERVATIONS

The clinical diagnosis of acute appendicitis is based on history and physical, laboratory evaluation, and imaging. Classic symptoms of appendicitis include vague periumbilical pain, anorexia/nausea/intermittent vomiting, migration of pain to the right lower quadrant, and low-grade fever. The diagnosis of acute appendicitis is made in approximately 90% of patients presenting with these symptoms. Laparoscopic appendectomy remains the most common treatment. However, increasing evidence suggests that broad-spectrum antibiotics, such as piperacillin-tazobactam monotherapy or combination therapy with either cephalosporins or fluroquinolones with metronidazole, successfully treats uncomplicated acute appendicitis in approximately 70% of patients. Specific imaging findings on computed tomography (CT), such as appendiceal dilatation (appendiceal diameter ≥7 mm), or presence of appendicoliths, defined as the conglomeration of feces in the appendiceal lumen, identify patients for whom an antibiotics-first management strategy is more likely to fail. CT findings of appendicolith, mass effect, and a dilated appendix greater than 13 mm are associated with higher risk of treatment failure (≈40%) of an antibiotics-first approach. Therefore, surgical management should be recommended in patients with CT findings of appendicolith, mass effect, or a dilated appendix who are fit for surgery, defined as having relatively low risk of adverse outcomes or postoperative mortality and morbidity. In patients without high-risk CT findings, either appendectomy or antibiotics can be considered as first-line therapy. In unfit patients without these high-risk CT findings, the antibiotics-first approach is recommended, and surgery may be considered if antibiotic treatment fails. In unfit patients with high-risk CT findings, perioperative risk assessment as well as patient preferences should be considered.

CONCLUSIONS AND RELEVANCE

Acute appendicitis affects 96.5 to 100 people per 100 000 adults per year worldwide. Appendectomy remains first-line therapy for acute appendicitis, but treatment with antibiotics rather than surgery is appropriate in selected patients with uncomplicated appendicitis.

Microbial Epidemiology of Acute and Perforated Appendicitis: A Post-Hoc Analysis of an EAST Multicenter Study

BACKGROUND

There are significant practice variations in antibiotic treatment for appendicitis, ranging from short-course narrow spectrum to long-course broad-spectrum. We sought to describe the modern microbial epidemiology of acute and perforated appendicitis in adults to help inform appropriate empiric coverage and support antibiotic stewardship initiatives.

METHODS

This is a post-hoc secondary analysis of the Multicenter Study of the Treatment of Appendicitis in America: Acute, Perforated, and Gangrenous (MUSTANG) which prospectively enrolled adult patients (age ≥ 18 years) diagnosed with appendicitis between January 2017 and June 2018 across 28 centers in the United States. We included all subjects with positive microbiologic cultures during primary or secondary (rescue after medical failure) appendectomy or percutaneous drainage. Culture yield was compared between low- and high-grade appendicitis as per the AAST classification.

RESULTS

A total of 3,471 patients were included: 230 (7%) had cultures performed, and 179/230 (78%) had positive results. Cultures were less likely to be positive in grade 1 compared to grades 3, 4, or 5 appendicitis with 2/18 (11%) vs 61/70 (87%) (p < .001). Only 1 subject had grade 2 appendicitis and culture results were negative. E. coli was the most common pathogen and cultured in 29 (46%) of primary appendectomy samples, 16 (50%) of secondary, and 44 (52%) of percutaneous drainage samples.

CONCLUSION

Culturing low-grade appendicitis is low yield. E. coli is the most commonly cultured microbe in acute and perforated appendicitis. This data helps inform empiric coverage for both antibiotics alone and as an adjunct to operative or percutaneous intervention.

Porphyromonas gingivalis outside the oral cavity

Porphyromonas gingivalis, a Gram-negative anaerobic bacillus present in periodontal disease, is considered one of the major pathogens in periodontitis. A literature search for English original studies, case series and review articles published up to December 2019 was performed using the MEDLINE, PubMed and GoogleScholar databases, with the search terms "Porphyromonas gingivalis" AND the potentially associated condition or systemic disease Abstracts and full text articles were used to make a review of published research literature on P. gingivalis outside the oral cavity. The main points of interest of this narrative review were: (i) a potential direct action of the bacterium and not the systemic effects of the inflammatory acute-phase response induced by the periodontitis, (ii) the presence of the bacterium (viable or not) in the organ, or (iii) the presence of its virulence factors. Virulence factors (gingipains, capsule, fimbriae, hemagglutinins, lipopolysaccharide, hemolysin, iron uptake transporters, toxic outer membrane blebs/vesicles, and DNA) associated with P. gingivalis can deregulate certain functions in humans, particularly host immune systems, and cause various local and systemic pathologies. The most recent studies linking P. gingivalis to systemic diseases were discussed, remembering particularly the molecular mechanisms involved in different infections, including cerebral, cardiovascular, pulmonary, bone, digestive and peri-natal infections. Recent involvement of P. gingivalis in neurological diseases has been demonstrated. P. gingivalis modulates cellular homeostasis and increases markers of inflammation. It is also a factor in the oxidative stress involved in beta-amyloid production.

Isolation and identification of microorganisms associated with automated teller machines on Federal Polytechnic Ede campus

Automated Teller Machines (ATM) are visited everyday by millions of people. This machine is accessible to the general public irrespective of class, age or race. The contact point of all ATM machines is the hand which on their own are ‘vaults’ of microorganisms. An elaborate survey was taken for complete assessment of possible microbial contamination in the Federal Polytechnic Ede campus. Selected ATM machines on campus were used as case study to characterize, identify and determine the degree of bacterial contamination of microorganisms and their potential as reservoir of microbes. Swabs were collected from each ATM screen, buttons, floor, user’s hand, and exposure of plates. After collection of the samples, they were plated in nutrient agar. The results showed the presence of increased bacterial count subsequently, most pathogens on characterization revealed the genus of the particular organisms E. coli, Pseudomonas, Staphylococcus aureus, Klebsiella, Micrococcus, Salmonella and Serratia. The study showed the potential hazard inherent in ATM machine usage and draws attention to our level of hand hygiene compliance.

Stress-related changes in the gut microbiome after trauma

BACKGROUND

The gut microbiome protects the host from infection by promoting epithelial integrity and providing basal immunologic stimulation. Disruption of this delicate ecosystem is linked to morbidity and mortality among critically ill patients, but the impact of traumatic injury on the gut microbiome is poorly understood. This study sought to identify alterations in gut microbiota following trauma and persistent stress in rodents without confounding antibiotics.

METHODS

Male Sprague-Dawley rats aged 9 weeks to 11 weeks were randomized to naive, lung contusion with hemorrhagic shock (LCHS), and LCHS plus either 7 (LCHS/CS 7/7) or 14 days (LCHS/CS 14) of restraint cylinder stress for 2 hours daily. Stool was collected on Days 0, 3, 7, and 14 for bacterial whole genome DNA isolation. Alpha diversity, or the number and relative abundance of unique bacterial species within each cohort, was assessed using Chao1 indices. Beta diversity, or the measure of differences in biodiversity across cohorts, was assessed by principle coordinate analysis. False discovery rate correction was applied to all statistical analyses and corrected for cohousing effects.

RESULTS

Rodent groups subject to restraint stress demonstrated a progressive increase in alpha diversity over time. These microbiota changes resolved after cessation of stress (LCHS/CS 7/7) but continued to increase among rats subjected to ongoing stress (LCHS/CS 14). The LCHS/CS 7/7 also demonstrated reductions in class Actinobacteria and increased abundance of the genus Bacteroides by Day 7, which resolved by Day 14. Increased abundance of Bacteroides was also noted in the LCHS/CS 14 cohort, suggesting the role of chronic stress in its destabilization.

CONCLUSION

This study points to persistent stress as a potential source of the destabilization of microbial diversity seen after trauma. This lack of microbiota stability could be associated with worse long-term outcomes in critically ill trauma patients. Further studies are warranted to elucidate mechanistic pathways and potential therapeutic modalities.

Potential role of microbiome in Chronic Fatigue Syndrome/Myalgic Encephalomyelits (CFS/ME)

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) is a severe multisystemic disease characterized by immunological abnormalities and dysfunction of energy metabolism. Recent evidences suggest strong correlations between dysbiosis and pathological condition. The present research explored the composition of the intestinal and oral microbiota in CFS/ME patients as compared to healthy controls. The fecal metabolomic profile of a subgroup of CFS/ME patients was also compared with the one of healthy controls. The fecal and salivary bacterial composition in CFS/ME patients was investigated by Illumina sequencing of 16S rRNA gene amplicons. The metabolomic analysis was performed by an UHPLC-MS. The fecal microbiota of CFS/ME patients showed a reduction of Lachnospiraceae, particularly Anaerostipes, and an increased abundance of genera Bacteroides and Phascolarctobacterium compared to the non-CFS/ME groups. The oral microbiota of CFS/ME patients showed an increase of Rothia dentocariosa. The fecal metabolomic profile of CFS/ME patients revealed high levels of glutamic acid and argininosuccinic acid, together with a decrease of alpha-tocopherol. Our results reveal microbial signatures of dysbiosis in the intestinal microbiota of CFS/ME patients. Further studies are needed to better understand if the microbial composition changes are cause or consequence of the onset of CFS/ME and if they are related to any of the several secondary symptoms.

Antibiotic-resistant microorganisms in patients with bloodstream infection of intraabdominal origin: risk factors and impact on mortality

BACKGROUND

Knowledge of resistance patterns is essential to choose empirical treatment. We aimed to determine the risk factors for antibiotic-resistant microorganisms (ARM) in intraabdominal infections (IAI) and their impact on mortality.

METHODS

Retrospective cohort study of patients with bacteremia from IAI origin in a single hospital between January 2006 and July 2017.

RESULTS

A total of 1485 episodes were recorded, including 381 (25.6%) due to ARM. Independent predictors of ARM were cirrhosis (OR 2; [95% CI 1.15-3.48]), immunosuppression (OR 1.49; 1.12-1.97), prior ceftazidime exposure (OR 3.7; 1.14-11.9), number of prior antibiotics (OR 2.33; 1.61-3.35 for 1 antibiotic), biliary manipulation (OR 1.53; 1.02-2.96), hospital-acquisition (OR 2.77; 1.89-4) and shock (OR 1.48; 1.07-2). Mortality rate of the whole cohort was 11.1%. Age (OR 1.03; 1.01-1.04), cirrhosis (OR 2.32; 1.07-4.38), urinary catheter (OR 1.99; 1.17-3.38), ultimately (OR 2.28; 1.47-3.51) or rapidly (OR 13.3; 7.12-24.9) fatal underlying disease, nosocomial infection (OR 2.76; 1.6-4.75), peritonitis (OR 1.95, 1.1-3.45), absence of fever (OR 2.17; 1.25-3.77), shock (OR 5.96; 3.89-9.13), and an ARM in non-biliary infections (OR 2.14; 1.19-3.83) were independent predictors of 30-day mortality. Source control (OR 0.24; 0.13-0.44) and 2015-2017 period (OR 0.29; 0.14-0.6) were protective.

CONCLUSION

Biliary manipulation and septic shock are predictors of ARM. The presence of an ARM from a non-biliary focus is a poor-prognosis indicator. Source control continues to be of paramount importance.

Burkholderia pseudomallei presenting with appendicular abscess: A great mimicker

We present an atypical presentation of melioidosis, which was an appendicular abscess in a man with newly diagnosed Type 2 diabetes mellitus, which has never been reported before worldwide.

Evaluation of role of hyperbilirubinemia as a new diagnostic marker of complicated appendicitis

BACKGROUND

In appendicitis, elevated intra-luminal pressure and ischemic necrosis of mucosa causes tissue gangrene or perforation. This leads to cytotoxin facilitated progressive bacterial invasion or translocation into the hepatic parenchyma through portal system. This phenomenon interferes with the bilirubin excretion into the bile canaliculi. In the present study, establishment of a possible role of hyperbilirubinemia as a marker of gangrenous/perforated appendicitis has been studied.

METHODS

After matching the inclusion and exclusion criteria, all cases of clinically diagnosed acute appendicitis were taken for this prospective, single center, observational study. Per-operative diagnosis was confirmed by histopathological examination.

RESULTS

Out of 110 subjects of acute appendicitis 41 subjects (37.27%) had hyperbilirubinemia. Out of 35 subjects diagnosed as complicated appendicitis 32 subjects (91.42%) had raised total bilirubin levels, while the remaining 03 (8.58%) had normal levels. Among 75 subjects diagnosed as acute simple appendicitis 09 subjects (12%) had raised total bilirubin level, while the remaining 66 subjects (88%) had normal levels. It was Mixed Type of Hyperbilirubinemia in gangrenous/perforated appendicitis. The sensitivity of Total serum bilirubin in predicting complicated appendicitis was found 91.43% (76.942% to 98.196%), where as the specificity of this test was 88.00% (78.439% to 94.363%). positive predictive value and negative predictive value were 78.03% and 95.65% respectively. Positive likelihood ratio and negative likelihood ratio were found to be 7.619 and 0.097 respectively taking prevalence of complicated appendicitis be 31.80%. Receiver Operating Characteristic curve was obtained which shows optimal criterion at Total Bilirubin Level 1.06 mg/dl where sensitivity was 91.43% and specificity was 97.33% at 95% confidence interval with 31.8% disease prevalence.

CONCLUSIONS

This is to conclude that Serum bilirubin level estimation, which is a simple, cheap and easily available laboratory test, can be added to the routine investigations in clinically suspected cases of acute appendicitis for early diagnosis of complications. Trial registration Registered with Clinical Trials Registry-India (ICMR-NIMS) with Registration number CTRI/2019/05/018879 Dated 01/05/2019. This was a prospective trial. Trial URL: http://ctri.nic.in/Clinicaltrials/pdf_generate.php?trialid=33113&EncHid=99780.32960&modid=1&compid=19%27,%2733113det%27 .

Acute appendicitis in people living with HIV: What does the emergency surgeon needs to know?

Acute appendicitis is among the commonest surgical emergencies seen in an acute setting. Individuals living with the Human Immunodeficiency Virus (HIV) and/or the Acquired Immunodeficiency Syndrome (AIDS) have an increased risk of encountering complications with acute appendicitis. We conducted a literature search using the words appendicitis and HIV in google scholar, Medline, Scopus and PubMed. The search also extended to cover HIV presented with acute appendicitis, their outcome during and following the management of acute appendicitis. Several studies showed that HIV is associated with a higher rate of acute appendicitis than the general population. HIV can directly affect the appendix, through opportunistic infections, immune reconstitution inflammatory syndrome associated with start of antiretroviral medication. High index of suspicion is needed to exclude conditions that mimic acute appendicitis (abdominal tuberculosis, pyelonephritis, cytomegalovirus, cryptosporidium, pneumococcus, Amoebic appendicitis and pill impaction). The clinical presentation may not be typical of acute appendicitis and can be associated with low white cell count and variable fever. The Alvarado score for predicting acute appendicitis can be used and more research is needed to establish cut-off point value. Computed tomography scan and ultrasound are widely used in clinical diagnosis. Importantly, acute appendicitis with HIV/AIDS can be associated with high rate of post-surgical complications like infections, delay of healing, perforation, peritonitis, intra-abdominal abscess and longer hospital stay. HIV/AIDS with acute appendicitis is complex condition. Therefore, we conclude that patients with known HIV and acute appendicitis should also be managed in close liaison with HIV physicians during, before and after surgical treatment.

Reducing Piperacillin and Tazobactam Use for Pediatric Perforated Appendicitis

BACKGROUND

Although perforated appendicitis is associated with infectious complications, the choice of antibiotic therapy is controversial. We assess the effectiveness and safety of an intervention to reduce piperacillin and tazobactam (PT) use for pediatric acute perforated appendicitis.

METHODS

This is a single-center, retrospective cohort study of children 18 y of age or younger who underwent primary appendectomy for perforated appendicitis between January 01, 2016 and June 30, 2019. An intervention to decrease PT use was implemented: the first phase was provider education (April 19, 2017) and the second phase was modification of electronic antibiotic orders to default to ceftriaxone and metronidazole (July 06, 2017). Preintervention and postintervention PT exposure, use of PT ≥ half of intravenous antibiotic days, and clinical outcomes were compared.

RESULTS

Forty children before and 109 after intervention were included and had similar baseline characteristics. PT exposure was 31 of 40 (78%) and 20 of 109 (18%) (P < 0.001), and use ≥ half of intravenous antibiotic days was 31 of 40 (78%) and 14 of 109 (13%) (P < 0.001), in the preintervention and postintervention groups, respectively. There was no significant difference in mean duration of antibiotic therapy (10.8 versus 9.8 d), mean length of stay (6.2 versus 6.5 d), rate of surgical site infection (10% versus 11%), or rate of 30-d readmission and emergency department visit (20% versus 20%) between the preintervention and postintervention periods, respectively.

CONCLUSIONS

Provider education and modification of electronic antibiotic orders safely reduced the use of PT for pediatric perforated appendicitis.

Appendectomy or Not? An Update on the Evidence for Antibiotics Only Versus Surgery for the Treatment of Acute Appendicitis in Children

Appendicitis is a common diagnosis in children being evaluated in the emergency department. After diagnosis, standard treatment has been surgical appendectomy; however, in recent years there is a growing body of evidence evaluating the possibility of nonoperative management in both children and adults. This review will present the current state of the pediatric literature that suggests patients may be successfully treated with antibiotics alone (ie, without surgery), but that a proportion of these patients will have recurrent appendicitis. Given that the literature regarding the option of antibiotic-only management compared with surgery is not yet definitive, there are many factors for providers to discuss with families and patients when considering treatment for acute appendicitis.

Educational Case: Acute Appendicitis

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Prospective multicentre cohort trial on acute appendicitis and microbiota, aetiology and effects of antimicrobial treatment: study protocol for the MAPPAC (Microbiology APPendicitis ACuta) trial

INTRODUCTION

Based on the epidemiological and clinical data, acute appendicitis can present either as uncomplicated or complicated. The aetiology of these different appendicitis forms remains unknown. Antibiotic therapy has been shown to be safe, efficient and cost-effective for CT-confirmed uncomplicated acute appendicitis. Despite appendicitis being one of the most common surgical emergencies, there are very few reports on appendicitis aetiology and pathophysiology focusing on the differences between uncomplicated and complicated appendicitis. Microbiology APPendicitis ACuta (MAPPAC) trial aims to evaluate these microbiological and immunological aspects including immune response in the aetiology of these different forms also assessing both antibiotics non-responders and appendicitis recurrence. In addition, MAPPAC aims to determine antibiotic and placebo effects on gut microbiota composition and antimicrobial resistance.

METHODS AND ANALYSIS

MAPPAC is a prospective clinical trial with both single-centre and multicentre arm conducted in close synergy with concurrent trials APPendicitis ACuta II (APPAC II) (per oral (p.o.) vs intravenous+p.o. antibiotics, NCT03236961) and APPAC III (double-blind trial placebo vs antibiotics, NCT03234296) randomised clinical trials. Based on the enrolment for these trials, patients with CT-confirmed uncomplicated acute appendicitis are recruited also to the MAPPAC study. In addition to these conservatively treated randomised patients with uncomplicated acute appendicitis, MAPPAC will recruit patients with uncomplicated and complicated appendicitis undergoing appendectomy. Rectal and appendiceal swabs, appendicolith, faecal and serum samples, appendiceal biopsies and clinical data are collected during the hospital stay for microbiological and immunological analyses in both study arms with the longitudinal study arm collecting faecal samples also during follow-up up to 12 months after appendicitis treatment.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of the Hospital District of Southwest Finland (Turku University Hospital, approval number ATMK:142/1800/2016) and the Finnish Medicines Agency. Results of the trial will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03257423.

Logistic regression model to predict acute uncomplicated and complicated appendicitis

INTRODUCTION

While patients with acute uncomplicated appendicitis may be treated conservatively, those who suffer from complicated appendicitis require surgery. We describe a logistic regression equation to calculate the likelihood of acute uncomplicated appendicitis and complicated appendicitis in patients presenting to the emergency department with suspected acute appendicitis.

MATERIALS AND METHODS

A cohort of 895 patients who underwent appendicectomy were analysed retrospectively. Depending on the final histology, patients were divided into three groups; normal appendix, acute uncomplicated appendicitis and complicated appendicitis. Normal appendix was considered the reference category, while acute uncomplicated appendicitis and complicated appendicitis were the nominal categories. Multivariate and univariate regression models were undertaken to detect independent variables with significant odds ratio that can predict acute uncomplicated appendicitis and complicated appendicitis. Subsequently, a logistic regression equation was generated to produce the likelihood acute uncomplicated appendicitis and complicated appendicitis.

RESULTS

Pathological diagnosis of normal appendix, acute uncomplicated appendicitis and complicated appendicitis was identified in 188 (21%), 525 (59%) and 182 patients (20%), respectively. The odds ratio from a univariate analysis to predict complicated appendicitis for age, female gender, log2 white cell count, log2 C-reactive protein and log2 bilirubin were 1.02 (95% confidence interval, CI, 1.01, 1.04), 2.37 (95% CI 1.51, 3.70), 9.74 (95% CI 5.41, 17.5), 1.57 (95% CI 1.40, 1.74), 2.08 (95% CI 1.56, 2.76), respectively. For the same variable, similar odds ratios were demonstrated in a multivariate analysis to predict complicated appendicitis and univariate and multivariate analysis to predict acute uncomplicated appendicitis.

CONCLUSIONS

The likelihood of acute uncomplicated appendicitis and complicated appendicitis can be calculated by using the reported predictive equations integrated into a web application at www.appendistat.com. This will enable clinicians to determine the probability of appendicitis and the need for urgent surgery in case of complicated appendicitis.

Hidden diagnosis behind viral infection: the danger of anchoring bias

Anchoring bias is one of the most common diagnostic biases that may lead to closed-minded thinking and could result in unnecessary tests, inappropriate patient management and even misdiagnosis. A 4-year-old boy was brought to the emergency department because of shaking chills. On the basis of bilateral swollen preauricular areas, high level of serum amylase and the prevalence of mumps, he initially received a diagnosis of mumps in spite of the shaking chills. However, blood culture turned out to be positive for two different kinds of bacteria. The patient finally received a diagnosis of polymicrobial bacteraemia resulting from suppurative appendicitis. We must consider and rule out bacteraemia in the differential diagnosis for patients who present with shaking chills, even in the presence of symptoms or information consistent with a more common viral infection such as mumps. In addition, intra-abdominal infection should be ruled out in the presence of polymicrobial enterobacteriaceae bacteraemia.

Bacterial culture and antibiotic susceptibility in patients with acute appendicitis

PURPOSE

Essential treatment of acute appendicitis is surgical resection with the use of appropriate antibiotics. In order to effectively treat acute appendicitis, it is important to identify the microorganism of acute appendicitis and evaluate the effective antibiotics.

METHODS

A total of 694 patients who underwent appendectomy for acute appendicitis and had positive microbial result between 2006 and 2015 were recruited. For microbial assessment, luminal contents of the appendix were swabbed after appendectomy. In patients with periappendiceal abscess, the specimens were obtained from abscess fluid. The patient characteristics, operative data, use of antibiotics, the results of microbiology, and postoperative morbidities including surgical site infection (SSI) were retrospectively reviewed.

RESULTS

The mean age was 38.2 (± 19.8) years, and 422 patients (60.8%) were male. Most of the operations were performed by conventional laparoscopy (83.1%), followed by single-port laparoscopy (11.8%). The most common microorganism was Escherichia coli (64.6%), which was susceptible to amoxicillin/clavulanate, ciprofloxacin, most cephalosporins, piperacillin/tazobactam, and imipenem. The second most common microorganism was Pseudomonas aeruginosa (16.4%), which was resistant to amoxicillin/clavulanate and cefotaxime. The rate of postoperative morbidity was 8.6%, and the most common type was superficial SSI (6.2%), followed by ileus (1.2%), gastroenteritis (0.7%), and organ/space SSI (0.3%). P. aeruginosa (odds ratio = 2.128, 95% confidence interval 1.077-4.206, P = 0.030) was the only significant microorganism associated with SSI according to multivariate analysis adjusting for other clinical factors.

CONCLUSIONS

In perforated appendicitis, the use of empirical antibiotics seems to be safe. In some cases of Pseudomonas infection, adequate antibiotics should be considered.

Once-Daily Ceftriaxone Plus Metronidazole Versus Ertapenem and/or Cefoxitin for Pediatric Appendicitis

BACKGROUND

Appendicitis is a common surgical emergency in pediatric patients, and broad-spectrum antibiotic therapy is warranted in their care. A simplified once-daily regimen of ceftriaxone and metronidazole (CTX plus MTZ) is cost effective in perforated patients. The goal of this evaluation is to compare a historic regimen of cefoxitin (CFX) in nonperforated cases and ertapenem (ERT) in perforated and abscessed cases with CTX plus MTZ for all cases in terms of efficacy and cost.

METHODS

A retrospective review compared outcomes of nonperforated, perforated, and abscessed cases who received the historic regimen or CTX plus MTZ. Length of stay, time to afebrile, time to full feeds, postoperative abscess, and wound infection rates, inpatient readmissions, and antibiotic costs were evaluated.

RESULTS

There were a total of 841 cases reviewed (494 nonperforated, 247 perforated, and 100 abscessed). Overall, the CTX plus MTZ group had a shorter time to afebrile (P < .001). Treatment groups did not differ in length of stay. Postoperative abscess rates were similar between groups (4.1% vs 3.3%, not significant). Other postoperative complications were similar between groups. Total antibiotic cost savings were over $110 000 during the study period (from November 2010 to June 2013).

CONCLUSIONS

Both CFX and/or ERT and CTX plus MTZ result in low abscess and complication rates, suggesting both are effective strategies. Treatment with CTX plus MTZ results in a shorter time to afebrile, while also providing significant antibiotic cost savings. Ceftriaxone plus MTZ is a streamlined, cost-effective regimen in the treatment of nonperforated, perforated, and abscessed appendicitis.

The Role of DNA Amplification and Cultural Growth in Complicated Acute Appendicitis

Bacterial growth of peritoneal fluid specimens obtained during surgical procedures for acute appendicitis may be useful to optimize further antibiotic therapy in complicated cases. DNA amplification represents a fast technique to detect microbial sequences. We aimed to compare the potential of DNA amplification versus traditional bacterial growth culture highlighting advantages and drawbacks in a surgical setting. Peritoneal fluid specimens were collected during surgery from 36 children who underwent appendectomy between May and December 2012. Real-time polymerase chain reaction (RT-PCR) and cultures were performed on each sample. RT-PCR showed an amplification of 16S in 18/36 samples, Escherichia coli (in 7 cases), Pseudomonas aeruginosa (3), Fusobacterium necrophorum (3), Adenovirus (2), E.coli (1), Klebsiella pneumoniae (1), Serratia marcescens/Enterobacter cloacae (1). Bacterial growth was instead observed only in four patients (3 E.coli and 1 P.aeruginosa and Bacteroides ovatus). Preoperative C-reactive protein and inflammation degree, the most reliable indicators of bacterial translocation, were elevated as expected. DNA amplification was a quick and useful method to detect pathogens and it was even more valuable in detecting aggressive pathogens such as anaerobes, difficult to preserve in biological cultures; its drawbacks were the lack of biological growths and of antibiograms. In our pilot study RT-PCR and cultures did not influence the way patients were treated.

Concurrent presentation of appendicitis and acute cholecystitis: diagnosis of rare occurrence

A 67-year-old woman presented with a 2-day history of central abdominal pain migrating to the right upper and lower abdomen. On examination she was normothermic but tachycardic. Inflammatory markers were noted to be elevated with a white cell count of 18.5×10(9)/L and C reactive protein of 265 mg/L. A CT scan revealed dual pathology of appendicitis and acute cholecystitis, which was confirmed intraoperatively and histologically.

Bacteriology and changes in antibiotic susceptibility in adults with community-acquired perforated appendicitis

This study evaluated bacterial etiology and antibiotic susceptibility in patients diagnosed with community-acquired perforated appendicitis over a 12-year-period. We retrospectively reviewed records of adult patients diagnosed with perforated appendicitis at an 800-bed teaching hospital between January 2000 and December 2011. In total, 415 culture-positive perforated appendicitis cases were analyzed. Escherichia coli was the most common pathogen (277/415, 66.7%), followed by Streptococcus species (61/415, 14.7%). The susceptibility of E. coli to ampicillin, piperacillin/tazobactam, ceftriaxone, cefepime, amikacin, gentamicin, and imipenem was 35.1%, 97.1%, 97.0%, 98.2%, 98.9%, 81.8%, and 100%, respectively. The overall susceptibility of E. coli to quinolones (ciprofloxacin or levofloxacin) was 78.7%. During the study period, univariate logistic regression analysis showed a significant decrease in E. coli susceptibility to quinolones (OR = 0.91, 95% CI 0.84-0.99, P = 0.040). We therefore do not recommend quinolones as empirical therapy for community-acquired perforated appendicitis.

Time to appendectomy and risk of perforation in acute appendicitis

IMPORTANCE

In the traditional model of acute appendicitis, time is the major driver of disease progression; luminal obstruction leads inexorably to perforation without timely intervention. This perceived association has long guided clinical behavior related to the timing of appendectomy.

OBJECTIVE

To evaluate whether there is an association between time and perforation after patients present to the hospital.

DESIGN, SETTING, AND PARTICIPANTS

Using data from the Washington State Surgical Care and Outcomes Assessment Program (SCOAP), we evaluated patterns of perforation among patients (≥18 years) who underwent appendectomy from January 1, 2010, to December 31, 2011. Patients were treated at 52 diverse hospitals including urban tertiary centers, a university hospital, small community and rural hospitals, and hospitals within multi-institutional organizations.

MAIN OUTCOMES AND MEASURES

The main outcome of interest was perforation as diagnosed on final pathology reports. The main predictor of interest was elapsed time as measured between presentation to the hospital and operating room (OR) start time. The relationship between in-hospital time and perforation was adjusted for potential confounding using multivariate logistic regression. Additional predictors of interest included sex, age, number of comorbid conditions, race and/or ethnicity, insurance status, and hospital characteristics such as community type and appendectomy volume.

RESULTS

A total of 9048 adults underwent appendectomy (15.8% perforated). Mean time from presentation to OR was the same (8.6 hours) for patients with perforated and nonperforated appendicitis. In multivariate analysis, increasing time to OR was not a predictor of perforation, either as a continuous variable (odds ratio =  1.0 [95% CI, 0.99-1.01]) or when considered as a categorical variable (patients ordered by elapsed time and divided into deciles). Factors associated with perforation were male sex, increasing age, 3 or more comorbid conditions, and lack of insurance.

CONCLUSIONS AND RELEVANCE

There was no association between perforation and in-hospital time prior to surgery among adults treated with appendectomy. These findings may reflect selection of those at higher risk of perforation for earlier intervention or the effect of antibiotics begun at diagnosis but they are also consistent with the hypothesis that perforation is most often a prehospital occurrence and/or not strictly a time-dependent phenomenon. These findings may also guide decisions regarding personnel and resource allocation when considering timing of nonelective appendectomy.

Stat3 activation in murine colitis induced by enterotoxigenic Bacteroides fragilis

BACKGROUND

Enterotoxigenic Bacteroides fragilis (ETBF), a molecular subclass of the common human commensal, B. fragilis, has been associated with inflammatory bowel disease. ETBF colitis is characterized by the activation of Stat3 and a Th17 immune response in the colonic mucosa. This study was designed to investigate the time course and cellular distribution of Stat3 activation in ETBF-colonized mice.

METHODS

C57BL/6 wild-type, C57BL/6, or Rag-1 mice were inoculated with saline, nontoxigenic B. fragilis or ETBF. Histologic diagnosis and mucosal Stat activation (immunohistochemistry, Western blot, and/or electrophorectic mobility shift assay) were evaluated over time (6-24 h, 1-7 d, and 1-18 mo after inoculation). Mucosal permeability was evaluated at 16 hours, 1 day, and 3 days. Mucosal immune responses were evaluated at 1 week, and 12 and 18 months.

RESULTS

ETBF induced rapid-onset colitis that persisted for up to 1 year. Stat3 activation (pStat3) was noted in the mucosal immune cells within 16 hours, with colonic epithelial cell activation evident at 24 hours after inoculation. ETBF-induced increased mucosal permeability was first observed at 24 hours after inoculation, after which the initial immune cell pStat3 activation was noted. Immune cell pStat3 was present in the absence of epithelial pStat3 (C57BL/6). Epithelial pStat3 was present in the absence of T and B cells (Rag-1 mice). pStat3 persisted in the epithelial and immune cells for 1 year, characterized by isolated pStat3-positive cell clusters, with varying intensity distributed through the proximal and distal colon. Similarly, mucosal Th17 immune responses persisted for up to 1 year. Loss of fecal ETBF colonization was associated with the loss of mucosal pStat3 and Th17 immune responses.

CONCLUSIONS

ETBF rapidly induces immune cell pStat3, which is independent of epithelial pStat3. This occurs before ETBF-induced mucosal permeability, suggesting that ETBF, likely through B. fragilis toxin and its action on the colonic epithelial cell, triggers mucosal immune cell Stat3 activation. Peak mucosal Stat3 activation (immune and epithelial cells) occurs subsequently when other colonic bacteria may contribute to the ETBF-initiated immune response due to barrier dysfunction. ETBF induces long-lived, focal colonic Stat3 activation and Th17 immune responses dependent on the ongoing ETBF colonization. Further study is needed to evaluate the early mucosal signaling events, resulting in epithelial Stat3 activation and the sequelae of long-term colonic Stat3 activation.

A model to select patients who may benefit from antibiotic therapy as the first line treatment of acute appendicitis at high probability

BACKGROUND

Randomized studies indicated that 88-95% of patients with acute appendicitis recover on antibiotics without surgery, although it is unclear which patient would benefit with high probability on antibiotics. We hypothesized that patients with phlegmonous appendicitis should be a group where antibiotics may be a sufficient treatment. Accordingly, our aim was to propose a model to support treatment application for unselected patients with acute appendicitis.

METHODS

Retrospective analyses of preoperative clinical and laboratory variables in 384 consecutive adult patients, who underwent appendectomy with histological examination of the appendix, were evaluated by logistic regressions. The proposed mathematical model was then evaluated on a prospectively collected population based material of 581 consecutive patients offered antibiotics as their first line treatment of acute appendicitis.

RESULTS

Patients with assumed appendicitis who fulfilled all criteria with CRP <60 g/L, WCC <12 × 10(9)/L, and age <60 years had 89% probability to have phlegmonous appendicitis. When these criteria were applied retrospectively on a prospective material, 88% of operated patients had phlegmonous inflammation and 89% had recovered on antibiotics without surgery.

CONCLUSION

Standard clinical and laboratory tests are individually weak predictors of phlegmonous appendicitis, but can be used in combinations as a bedside instrument to select patients suitable for antibiotic therapy.

The diagnostic value of a panel of serological markers in acute appendicitis

BACKGROUND

Appendicitis is a frequent reason for hospital admissions. Elevated C-reactive protein, white blood cell count, and serum bilirubin have been suggested as individual markers for appendicitis and appendiceal perforation. The aim of this study was to analyze if a combination of serologic markers could increase the prognostic accuracy of diagnosing non-perforated and perforated appendicitis.

MATERIAL AND METHODS

Demographic data, histological findings, blood tests, and clinical symptoms were collected on all patients who underwent a diagnostic laparoscopy, a laparoscopic appendectomy, or conventional (open) appendectomy between May 2009 and May 2012 from a surgical department. The patients were grouped into those with either perforated appendicitis, non-perforated appendicitis, or differential diagnosis. Univariate and multivariate models were used to identify which markers were useful in predicting acute and perforated appendicitis, and receiving operating characteristics curves were used to find the specificity, sensitivity, and the negative and positive predictive values.

RESULTS

A total of 1008 patients were operated under suspicion of appendicitis. From these, 700 patients had a pathologically verified inflamed appendix and 190 had a perforated appendix. Patients with acute appendicitis had significantly higher blood levels of white blood cell, bilirubin, C-reactive protein, and alanine transaminase than patients without appendicitis. Patients with perforated appendicitis had significantly higher levels of white blood cell, bilirubin, and C-reactive protein than patients with non-perforated appendicitis. The highest positive predictive value to discriminate between acute appendicitis and non-appendicitis was of a linear regression model combining white blood cell count, bilirubin, and alanine transaminase. C-reactive protein levels and a linear regression model, including white blood cell count, bilirubin, and C-reactive protein levels as variables, had the highest negative predictive values when discriminating between perforated and non-perforated appendicitis.

CONCLUSION

Combining blood markers was useful in predicting appendicitis and perforated appendicitis. In addition to C-reactive protein and white cell count, blood levels of bilirubin, and alanine transaminase may be useful.

The microbiology of bacterial peritonitis due to appendicitis in children

AIM

The aim of this study was to investigate the microbiology of secondary bacterial peritonitis due to appendicitis and the appropriateness of current antimicrobial practice in one institution.

METHODS

A 14-year retrospective single-centre study of 69 consecutive paediatric patients (age 1-14 years) with appendicitis-related peritonitis and positive peritoneal specimen cultures was conducted. Post-operative outcomes, microbiology and antibiotic susceptibility of peritoneal isolates were analysed in all patients.

RESULTS

Escherichia coli was identified in 56/69 (81 %) peritoneal specimens; four isolates were resistant to amoxicillin-clavulanate, and one other isolate was resistant to gentamicin. Anaerobes were identified in 37/69 (54 %) peritoneal specimens; two anaerobic isolates were resistant to amoxicillin-clavulanate and one isolate was resistant to metronidazole. Pseudomonas aeruginosa was identified in 4/69 (6 %) peritoneal specimens, and all were susceptible to gentamicin. Streptococcal species (two Group F streptococci and three β-haemolytic streptococci) were identified in 5/69 (7 %) specimens, and all were susceptible to amoxicillin-clavulanate. Combination therapy involving amoxicillin-clavulanate and aminoglycoside is appropriate empirical treatment in 68/69 (99 %) patients. Addition of metronidazole to this regime would provide 100 % initial empirical coverage. Inadequate initial empiric antibiotic treatment and the presence of amoxicillin-clavulanate resistant E. coli were independent predictors of the post-operative infectious complications observed in 14/69 (20 %) patients.

CONCLUSION

E. coli and mixed anaerobes are the predominant organisms identified in secondary peritonitis from appendicitis in children. Inadequate initial empirical antibiotic and amoxicillin-clavulanate resistant E. coli may contribute to increased post-operative infectious complications. This study provides evidence-based information on choice of combination therapy for paediatric appendicitis-related bacterial peritonitis.

A case of fitz-hugh-curtis syndrome complicated by appendicitis conservatively treated with antibiotics

A 27-year-old woman developed a low grade fever and increased vaginal discharge that persisted for 2 weeks. Intermittent abdominal pain in the right upper quadrant had been experienced over the previous few days. Due to her clinical manifestations and typical abdominal computed tomography (CT) findings, including hepatic capsular enhancement and hepatomegaly, a diagnosis of Fitz-Hugh-Curtis syndrome was made. The early empirical use of antibiotics, azithromycin and levofloxacin, partially improved her symptoms. However, the low grade fever persisted and additional abdominal pain developed in the right lower quadrant. Based on the radiological evidence of an enlarged appendix with wall thickening, a diagnosis of appendicitis was additionally made, which was thought to occur secondarily to the genital tract infection. Following the administration of antibiotics ceftriaxone and cefditoren pivoxil, her symptoms were completely resolved without the need for any surgical intervention. Here, we report the first case of Fitz-Hugh-Curtis syndrome complicated by appendicitis, which was conservatively managed with antibiotic treatment alone. In this case, the overgrowth of pathogens within the genital tract and their direct penetration into the appendix was thought to be responsible for the development of appendicitis.

Hyperbilirubinemia as a predictor of gangrenous/perforated appendicitis: a prospective study

BACKGROUND

THE AIMS OF THE STUDY WERE: 1) to establish the role of hyperbilirubinemia as a new diagnostic tool to predict gangrenous/perforated appendicitis; and 2) to compare other variables such as age, duration of symptoms, clinical profile, white blood cell count, C-reactive protein and ultrasound in a similar role.

METHODS

This is a prospective study conducted on 50 consecutive cases of acute appendicitis admitted to the emergency ward. These were subjected to investigations to support the diagnosis. These cases were also subjected to liver function tests and clinical diagnosis was confirmed perioperatively and post-operatively by histopathological examination. Their clinical and investigative data were compiled and analyzed. Statistical analysis was performed using either chi square test or fisher's exact test. The level of significance was set at P< 0.05.

RESULTS

Total serum bilirubin including both direct and indirect was found to be significantly increased in case of acute suppurative appendicitis. Serum bilirubin was much higher (P <0.000) in cases of gangrenous/perforated appendicitis.

CONCLUSION

Serum bilirubin is an important adjunct in diagnosing the presence of gangrenous/perforated appendicitis.

Antibiotics as first-line therapy for acute appendicitis: evidence for a change in clinical practice

BACKGROUND

Randomized studies have indicated that acute appendicitis may be treated by antibiotics without the need of surgery. However, concerns have been raised about selection bias of patients in such studies. Therefore, the present study was aimed to validate previous findings in randomized studies by a full-scale population-based application.

METHODS

All patients with acute appendicitis at Sahlgrenska University Hospital (May 2009 and February 2010) were offered intravenous piperacillin plus tazobactam according to our previous experience, followed by 9 days out-hospital oral ciprofloxacin plus metronidazole. Endpoints were treatment efficacy and complications. Efficient antibiotic treatment was defined as recovery without the need of surgery beyond 1 year of follow-up.

RESULTS

A total of 558 consecutive patients were hospitalized and treated due to acute appendicitis. Seventy-nine percent (n = 442) received antibiotics as first-line therapy and 20 % (n = 111) had primary surgery as the second-line therapy. Seventy-seven percent of patients on primary antibiotics recovered while 23 % (n = 100) had subsequent appendectomy due to failed initial treatment on antibiotics. Thirty-eight patients (11 %) of the 342 had experienced recurrent appendicitis at 1-year follow-up. Primary antibiotic treatment had fewer complications compared to primary surgery.

CONCLUSIONS

This population-based study confirms previous results of randomized studies. Antibiotic treatment can be offered as the first-line therapy to a majority of unselected patients with acute appendicitis without medical drawbacks other than the unknown risk for long-term relapse, which must be weighed against the unpredicted but well-known risk for serious major complications following surgical intervention.

Transposon mutagenesis of the anaerobic commensal, Bacteroides fragilis, using the EZ::TN5 transposome

Genetic analysis of Bacteroides fragilis (BF) is hindered because of the lack of efficient transposon mutagenesis methods. Here, we describe a simple method for transposon mutagenesis using EZ::TN5, a commercially available system that we optimized for use in BF638R. The modified EZ::TN5 transposon contains an Escherichia coli conditional origin of replication, a kanamycin resistance gene for E. coli, an erythromycin resistance gene for BF , and 19 basepair transposase recognition sequences on either ends. Electroporation of the transposome (transposon-transposase complex) into BF638R yielded 3.2 ± 0.35 × 10(3) CFU μg(-1) of transposon DNA. Modification of the transposon by the BF638R restriction/modification system increased transposition efficiency sixfold. Electroporation of the EZ::TN5 transposome results in a single-copy insertion of the transposon evenly distributed across the genome of BF638R and can be used to construct a BF638R transposon library. The transposon was also effective in mutating a BF clinical isolate and a strain of the related species, Bacteroides thetaiotaomicron. The EZ::TN5-based mutagenesis described here is more efficient than other transposon mutagenesis approaches previously reported for BF.

[Microbiological diagnosis of intra-abdominal infections]

Intra-abdominal infections represent a large and wide group of diseases which include intra- and retro-peritoneal infections. Some of them could be defined as uncomplicated, where the infectious process is limited to the organ or tissue of origin (appendicitis, diverticulitis, cholecystitis…). Complications occur when the infection spreads to the peritoneum, triggering localised peritonitis and abdominal abscesses. Most intra-abdominal infections are due to perforation or inflammation of the intestinal wall. The microorganisms that cause these infections come from the gastrointestinal flora, and therefore produce polymicrobial infections mixed with a predominance of anaerobic bacteria. Microbiological diagnosis is essential to determine the aetiology and the susceptibility of antimicrobial agents of the microorganism involved, especially in nosocomial infections or in community infections in predisposed patients due to increasing bacterial resistance to antimicrobial agents, multidrug resistance and fungal involvement. Despite the advances in microbiological diagnosis, in the case of intra-abdominal infections it still remains direct, being based on stains and cultures, the most notable progress is the introduction of mass spectrometry (MALDI-TOF) for the rapid identification of the pathogens involved. This review will provide recommendations on the collection, transport and microbiological processing of clinical specimens. Comments on the pathogenesis, clinical and microbiological diagnosis of peritonitis primary, secondary, tertiary and peritonitis (and other infections) associated with peritoneal dialysis, intra-abdominal abscesses (intraperitoneal, retroperitoneal and visceral), biliary tract infections, appendicitis and diverticulitis are also presented.

Appendectomy versus antibiotic treatment for acute appendicitis

BACKGROUND

Acute appendicitis is one of the most common causes of acute abdominal pain. Present day treatment of choice for acute appendicitis is appendectomy, however complications are inherent to operative treatment. Though surgical appendectomy remains the standard treatment, several investigators have investigated conservative antibiotic treatment of acute appendicitis and reported good results.

OBJECTIVES

Is antibiotic treatment as effective as surgical appendectomy (laparoscopic or open) in patients with acute appendicitis on recovery within two weeks, without major complications (including recurrence) within one year?

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 6, 2011); MEDLINE (until June 2011); EMBASE (until June 2011); Prospective Trial Registers (June 2011) and reference lists of articles.

SELECTION CRITERIA

Randomised and quasi-randomised clinical trials (RCT and qRCT) comparing antibiotic treatment with appendectomy in patients with suspected appendicitis were included. Excluded were studies which primarily focused on the complications of acute appendicitis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. The review authors contacted the trial authors for additional information if required. Statistical analysis was carried out using Review Manager and MetaAnalyst. A non-inferiority analysis was performed, comparing antibiotic treatment (ABT) to the gold standard (appendectomy). By consensus, a 20% margin of non-inferiority was considered clinically relevant.

MAIN RESULTS

Five RCT's (901 patients) were assessed. In total 73.4% (95% CI 62.7 to 81.9) of patients who were treated with antibiotics and 97.4 (95% CI 94.4 to 98.8) patients who directly got an appendectomy were cured within two weeks without major complications (including recurrence) within one year. The lower 95% CI was 15.2% below the 20% margin for the primary outcome.

AUTHORS' CONCLUSIONS

The upper bound of the 95% CI of ABT for cure within two weeks without major complications crosses the 20% margin of appendectomy, so the outcome is inconclusive. Also the quality of the studies was low to moderate, for that reason the results should be interpret with caution and definite conclusions cannot be made. Therefore we conclude that appendectomy remains the standard treatment for acute appendicitis. Antibiotic treatment might be used as an alternative treatment in a good quality RCT or in specific patients or conditions were surgery is contraindicated.

Single incision versus conventional multi-incision appendicectomy for suspected appendicitis

BACKGROUND

Appendicectomy is a well established surgical procedure used in the management of acute appendicitis.  The operation can be performed with minimally invasive surgery (laparoscopic) or as an open procedure. A recent development in appendicectomy has been the introduction of less invasive single incision laparoscopic surgery, using a single multi-luminal port or multiple mono-luminal ports, through a single skin incision. There are yet unanswered questions regarding the efficacy of this new and novel technique including: patient benefit and satisfaction, complications, long-term outcomes, and survival.

OBJECTIVES

The aim of this review is to perform meta-analysis using data from available trials comparing single incision with conventional multi-incision laparoscopic appendicectomy for appendicitis, in order to ascertain any differences in outcome.

SEARCH STRATEGY

We searched the electronic databases including MEDLINE/PubMed (from 1980 to December 2010), EMBASE/Ovid (from 1980 to December 2010) and CENTRAL (The Cochrane Library 2010, Issue 11) with pre-specified terms. We also searched reference lists of relevant articles and reviews, conference proceedings and ongoing trial databases.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of patients with appendicitis, or symptoms of appendicitis, undergoing laparoscopic appendicectomy, in which at least one arm involves single incision procedures and another multi-incision procedures.

DATA COLLECTION AND ANALYSIS

There were no RCTs or prospectively controlled trials found that met the inclusion criteria.

MAIN RESULTS

Three authors performed study selection independently.No studies that met the inclusion criteria of this review were identified. Current evidence exists only the form of case-series.This review has been authored as 'empty' pending the results of 5 ongoing trials.

AUTHORS' CONCLUSIONS

No RCTs comparing single incision laparoscopic appendectomy with multi-incision surgery could be identified. No definitive conclusions can be made at this time. Well designed prospective RCTs are required in order to evaluate benefit or harm from laparoscopic surgical approaches for appendicectomy. Until appropriate data has been reported, the institutional polices of healthcare providers must be based on the clinical judgement of experts in the field.