Bacterial flora of the appendix fossa in appendicitis and postoperative wound infection

Bacteria were isolated from 153 (47.5%) swabs of the appendix fossa in 322 patients undergoing appendicectomy. The commonest organism was Bacteroides species found in 78% of specimens. Other Gram-negative bacilli such as Klebsiella, or Enterobacter, and Esch. coli were present in 29 and 27% respectively. Gram-positive cocci were less frequently isolated.A positive culture was obtained more commonly in perforated appendicitis (79%) than where chronic fibrosis, lymphoid hyperplasia, or acute appendicitis was present or when the appendix was normal. Bacteroides was isolated twice as often in perforated appendicitis.The incidence of wound infection was 19% and varied according to the state of the appendix, being 63% in perforated appendicitis and 9.5% where lymphoid hyperplasia was present. Bacteroides was isolated from over 90% of the wound infections.In the patients with perforated appendicitis where effective chemotherapy was given the incidence of wound infection was 15% whereas in untreated or inappropriately treated patients it was over 50%.The isolation of bacteroides requires special precautions to be taken both in the collection of the specimen and laboratory culture. It is important that the chemotherapy of postappendicectomy infections include an antibiotic active against bacteroides.     

Lymph node pathology in Henoch-Schönlein purpura

This report describes two cases of Henoch-Schönlein purpura with unusual lymph node pathology. The patients presented with severe colicky abdominal pain mimicking acute appendicitis but a normal appendix was removed in each case. Enlarged mesenteric lymph nodes were removed, with a clinical suspicion of Yersinia infection. Cultures and serology were negative. Histological examination of the lymph nodes revealed follicular granulomas, follicular microabscesses and leucocytoclastic vasculitis. Immunohistochemical studies revealed deposition of IgA, IgG and C₃ in the vessel walls, the finding of IgA supporting a diagnosis of Henoch-Schönlein purpura.     

Parasitic infection of the appendix as a cause of acute appendicitis

The association between parasitic infection of the appendix and acute appendicitis has been widely investigated. The aim of this retrospective study was to evaluate the prevalence of parasitic infection of the appendix in a tropical area at southeast Brazil and to assess its possible relation to acute appendicitis in surgically removed appendices. Of the 1,600 appendectomies performed during a 10-year period, 24 (1.5%) were found to have helminths within the appendix. Enterobius vermicularis was observed in 23 of the 24 specimens (95.8%), and Taenia sp. was detected in only one case. Sixteen patients (66.7%) were less than 10 years old; 15 patients were male and nine female; 21 patients were white, and three were nonwhites. Pathologic analysis disclosed acute neutrophilic inflammation in the appendix wall in 12 of the 24 specimens and lymphoid hyperplasia in 10 of the 24 appendices. Gangrenous appendicitis was diagnosed in three cases, and peritonitis was found in 11 of the 24 infected appendices. The results of the present study indicate that E. vermicularis is the commonest worm found in the appendix and that its presence can cause pathologic changes ranging from lymphoid hyperplasia to acute phlegmonous inflammation with life-threatening complications like gangrene and peritonitis.     

Predictive value of stool examination in acute diarrhea

We prospectively evaluate the value of fecal blood and fecal leukocytes in predicting whether acute diarrhea in adults is associated with a stool culture positive for a bacterial pathogen. One hundred thirteen patients, aged 19 to 50 years, seen in a two-year period in an urban adult outpatient setting underwent stool culture for the presenting symptom of diarrhea. Heterosexual men represented 48% of the cohort, women represented 17%, and homosexual men represented 35%. Overall, 53 (47%) of the patients had positive stool cultures for enteric pathogens. Campylobacter jejuni was the most common organism in the entire cohort, but Shigella species were most common in homosexual men. The best predictive variables for a stool culture positive for a bacterial pathogen were the presence of both fecal leukocytes and fecal blood in the stool, compared with only one or neither. When both were present, the sensitivity was 81%, the specificity 74%, and the predictive values of a positive and negative test were 81% and 83%, respectively; the likelihood ratio was 4.87. When homosexual men and the rest of the cohort were analyzed separately, the combination of fecal leukocytes and fecal blood remained the best method of predicting a positive stool culture in both. Examination of stool for fecal leukocytes and fecal blood is a rapid, reliable, and inexpensive way to differentiate between bacterial and other causes of acute diarrhea in the adult acute care setting.     

Severe diarrhea associated withArcobacter butzleri

Two patients with chronic disease (diabets mellitus type I, hyperuricemia and alcohol abuse, respectively) were hospitalized with persistent diarrhea and severe abdominal cramps. Using routine methods, the only pathogen isolated in stool specimens wasArcobacter butzleri. In both cases acute symptoms subsided quickly after antibiotic therapy. After termination of antibiotic treatment,Arcobacter butzleri could no longer be detected in stool specimens. Although very little is known about the clinical significance ofArcobacter butzleri infections in humans, it is highly likely that in both casesArcobacter butzleri played a major causative role in acute disease.     

Improved Microbiological Techniques Using the Polymerase Chain Reaction and Pulsed-Field Gel Electrophoresis for Diagnosis and Follow-Up of Enterohaemorrhagic Escherichia coli Infection

 The aims of the present investigation were to evaluate the microbiological diagnostic procedures, especially polymerase chain reaction (PCR) versus culture and seroagglutination, in relation to the clinical features of enterohaemorrhagic Escherichia coli (EHEC) infection and to study the status of EHEC in the western part of Sweden. During 1997 and 1998, stool specimens from 3,948 patients were analysed by PCR for the presence of EHEC with verotoxin (VT)1- and/or VT2-producing DNA sequences. The stool specimens were also cultured for Escherichia coli O157 : H7, Salmonella, Campylobacter, Shigella and Yersinia. Fifty-five patients were positive by PCR. Thirty-nine patients were positive for EHEC by PCR and culture. Of these, 29 were infected with EHEC serogroup O157 : H7 strains. All EHEC isolates were analysed by pulsed-field gel electrophoresis (PFGE); 17 different clones were identified. Studies on the duration of the presence of EHEC in the gut showed that EHEC often disappears rather quickly, i.e. within 2 weeks. In one patient, however, EHEC remained for several months. In conclusion, PCR, rather than culture and agglutination, should be the method of choice for microbiological diagnosis of EHEC infection. PCR is more sensitive than culture for detecting EHEC in the gut.     

Ultrasound with graded compression in the evaluation of acute appendicitis

Acute appendicitis is the most common diagnosis made (in the Western world) in patients with an "acute abdomen." Although the mortality rate has been vastly reduced, the diagnostic inaccuracy rate of 15% to 20% has remained unchanged in the past 100 years. In this article, the authors report the ultrasonographic findings in 80 patients examined using a small linear-array transducer, which enables direct visualization of the inflamed appendix. During 22 months, 80 patients (28 males and 52 females; age range, 3 to 81 years; mean, 32.3 years) with equivocal clinical signs and symptoms of acute appendicitis were examined sonographically. Of the 29 patients whose appendicitis was verified at surgery, ultrasonography was positive in 26, with an overall sensitivity of 90%. Of the 51 patients who did not have appendicitis, ultrasonography was negative in all, with a specificity of 100%. The authors concur with reports in the literature that ultrasonography is helpful in diagnosing appendicitis.     

Value of routine stool cultures in hospitalized patients with diarrhea

In a prospective study conducted over a six-month period, the relative yield of 721 routine cultures of stool from adult inpatients as a function of the time after hospital admission was assessed.Salmonella, Campylobacter, Shigella orYersinia spp. were recovered from 10.9 % (41/377) of patients within three days of hospitalization and from only 1.5 % (5/344) after three days. However, a review of these patients' charts did not suggest nosocomial transmission but rather a delay in stool collection or asymptomatic carriage.Clostridium difficile was isolated with a high frequency in patients both within and after three days of hospitalization (10.3 % and 10.2 %, respectively). Thus, stool specimens from adults hospitalized for more than three days should not be cultured except forClostridium difficile unless there are plausible clinical or epidemiological reasons to do so.     

Sonography in acute appendicitis

In two patients with an equivocal clinical diagnosis of acute appendicitis, high-resolution sonography demonstrated an inflamed appendix. The appendix of each appeared grossly abnormal and was removed at laparotomy. Pathologic examination confirmed the diagnosis of acute appendicitis. Coupled with a review of the literature, the authors suggest high-resolution sonography as the examination of choice in patients with equivocal clinical findings of acute appendicitis.     

Current evidence for human yersiniosis in Ireland

Yersiniosis associated with abdominal pain was commonly reported in Ireland in the 1980s. However, the Health Protection Surveillance Centre (HPSC) currently records only three to seven notified cases of yersiniosis per year. The most common cause of yersiniosis worldwide is Yersinia enterocolitica, and the leading source for this organism is consumption of pork-based food products. In contrast to the apparent current scarcity of yersiniosis cases in humans in Ireland, pathogenic Y. enterocolitica are detectable in a high percentages of pigs. To establish whether the small number of notifications of human disease was an underestimate due to lack of specific selective culture for Yersinia, we carried out a prospective culture study of faecal samples from outpatients with diarrhoea, with additional culture of throat swabs, appendix swabs and screening of human sewage. Pathogenic Yersinia strains were not isolated from 1,189 faeces samples, nor from 297 throat swabs, or 23 appendix swabs. This suggested that current low notification rates in Ireland are not due to the lack of specific Yersinia culture procedures. Molecular screening detected a wider variety of Y. enterocolitica-specific targets in pig slurry than in human sewage. A serological survey for antibodies against Yersinia YOP (Yersinia Outer Proteins) proteins in Irish blood donors found antibodies in 25?%, with an age-related trend to increased seropositivity, compatible with the hypothesis that yersiniosis may have been more prevalent in Ireland in the recent past.     

A comparison of surgical impression, histological findings and microbiological results at open appendicectomy

There is no accurate predictor of complications following open appendicectomy. Surgical impression, histological findings and peritoneal culture swabs have been used. The value of peritoneal culture swab was assessed in this study. All patients undergoing open appendicectomy between January 2003 and December 2005 were included in the study. During the 24-month period, 952 patients underwent open appendicectomy. Peritoneal culture swabs were taken from 309 patients (32%). There was a significant difference in the mean postoperative length of stay +/- SEM between those with a positive culture (7 days +/- 0.6), those with a sterile culture result (3.7 days +/- 0.2) and those on whom a culture swab was not taken (4.9 days +/- 0.3); p<0.0001, ANOVA. Surgeons were more likely to overcall the severity of the appendix pathology (p < 0.0001 surgical vs. histological findings; Fisher's exact test), however, there was no significant difference in the power of surgical or histological assessment of the appendicitis at predicting a positive peritoneal culture result. Complex appendicitis was more likely to be associated with a positive peritoneal culture (P < 0.0001; Fisher's exact test). No antibiotic regime was changed on the basis of a positive culture swab. Fifteen patients were readmitted within 6 months of appendicectomy, predictors of readmission included histologically confirmed complex appendicitis and a positive peritoneal culture swab. Peritoneal culture swabs do not improve immediate postoperative therapy based on surgical impression and rapid histological reporting, however, the routine use of peritoneal culture swabs may be of value in identifying patients requiring outpatient follow-up.     

Acute appendicitis in minority communities: an epidemiologic study.

This study examines the incidence and epidemiological factors of acute appendicitis in various ethnic groups in an urban minority community. The charts of 278 consecutive patients who underwent appendectomy at The Bronx-Lebanon Hospital Center, Bronx, New York, between January 1988 and December 1990 were reviewed. Thirty-eight patients who underwent incidental appendectomy and one patient who had an interval appendectomy were excluded. The remaining 239 patients, all of whom had acute appendicitis, constituted the study population. The incidence of appendicitis for each ethnic group was calculated as a percentage of the total emergency surgical admissions for that group. Acute appendicitis constituted 3.1% of all emergency admissions to the surgical service over the period studied and represented 4.5% of surgical service admissions from the emergency department in Hispanics, 1.9% in African Americans, 1.5% in whites, and 21% in Asians. These differences were statistically significant except some comparisons involving whites. There were no significant differences in the pathological findings regarding the diseased appendix in different racial groups. These results indicate that acute appendicitis is responsible for a higher incidence of emergency admissions among Hispanics than among African Americans. This finding was statistically significant. High white blood cell counts indicated inflammation of the appendix, but had no predictive value for the type of pathology. Surgical findings were similar in all groups.     

Rotavirus infection increases the risk of bacteremia in children with nontyphoid <Emphasis Type="Italic">Salmonella</Emphasis> gastroenteritis

To evaluate whether there is any impact of rotavirus infection on nontyphoid Salmonella (NTS) gastroenteritis, a total of 207 diarrheal children who had positive stool culture for NTS and also a stool examination for the rotavirus antigen were retrospectively analyzed. According to the positivity of the stool rotavirus antigen, patients were divided into two groups and compared with regard to demographic data, clinical features, laboratory findings, and complications. The results showed that there were no significant differences between the two groups of patients with regard to demographic data, clinical features, and laboratory findings, except that vomiting was more common in patients with a coinfection of rotavirus (70.4% vs 40.0%, P = 0.003). Complication by bacteremia occurred more frequently in patients with coinfection of rotavirus (32% vs 9.3%, P = 0.004), but none of them developed extraintestinal focal infections, which were observed only in patients with isolated NTS infection. Our study indicated that concomitant rotavirus infection increased the risk of bacteremia in children with NTS gastroenteritis, although the prognosis remained favorable.     

Is there a role for leukocyte and CRP measurements in the diagnosis of acute appendicitis in the elderly?

Objectives: The diagnosis of acute appendicitis is still difficult and the results are unsatisfactory in three particular patient groups: in children, in fertile-age women and in elderly patients. As our population ages, the challenge for expedient diagnosis and intervention in older age groups will become more and more significant. The present study aimed at clarifying the role of leukocyte count and C-reactive protein (CRP) measurements in the diagnosis of acute appendicitis in the elderly. In particular, are there patients with acute appendicitis but unelevated leukocyte count and CRP? Methods: Eighty-three consecutive elderly patients underwent appendectomy for suspected acute appendicitis. The mean leukocyte count and CRP value were calculated in patients with an uninflamed appendix (group A) and in those with acute appendicitis (group B). The percentages of patients with: (1) both values unelevated; (2) only leukocyte count elevated; (3) only CRP value elevated; (4) both values elevated were calculated within the groups A and B. Results: There was no statistically significant difference in leukocyte counts or CRP values between patients with an uninflamed appendix (group A) and those with acute appendicitis (group B). When the patients were divided into the four subgroups, the most conspicuous finding was that group B (acute appendicitis, n=73) contained no patients with both values unelevated. Conclusions: Although elevated leukocyte count and CRP value cannot effectively establish the diagnosis of acute appendicitis in the elderly, unelevated values exclude it. Accordingly, appendectomy is not recommended to be performed in an elderly patient with unelevated leukocyte count and CRP value, although clinical symptoms and signs indicate acute appendicitis.     

Three-Hour Molecular Detection of Campylobacter,Salmonella, Yersinia,and Shigella Species in Feces with Accuracy as High as That of Culture

Campylobacter jejuni and Salmonella, Shigella, and Yersinia species (along with Shiga toxin-producing Escherichia coli) are the most common causes of acute bacterial diarrheal disease in the United States. Current detection techniques are time-consuming, limiting usefulness for patient care. We developed and validated a panel of rapid PCR assays for the detection and identification of C. jejuni, C. coli, Salmonella, and Yersinia species and Shigella and enteroinvasive E. coli in stool samples. A total of 392 archived stool specimens, previously cultured for enteric pathogens, were evaluated by PCR. Overall, 104 stool specimens had been culture positive (C. jejuni/coli [n = 51], Salmonella species [n = 42], Shigella species [n = 6], and Yersinia species [n = 5]). Compared to culture, the overall sensitivity and specificity of PCR detection of these organisms were 92 and 98% (96/104 and 283/288), respectively, from fresh or Cary Blair stool (P = 0.41); 87 and 98% (41/47 and 242/246), respectively, from fresh stool (P = 0.53); and 96 and 98% (55/57 and 41/42), respectively, from Cary Blair stool (P = 0.56). For individual genera, PCR was as sensitive as the culture method, with the exception of Salmonella culture using selenite enrichment for which PCR was less sensitive than culture from fresh, but not Cary Blair (P = 0.03 and 1.00, respectively) stools. This PCR assay panel for the rapid diagnosis of acute infectious bacterial diarrheal pathogens has a sensitivity and specificity equivalent to that of culture for stools in Cary Blair transport medium. Paired with reflexive culture of stools testing positive, this should provide an improvement in care for patients with acute infectious diarrheal disease.Despite advances in water treatment, food safety, and sanitary conditions, acute diarrheal disease remains a leading cause of morbidity and mortality worldwide. Most bacterial enteric infections in the United States originate within the food supply chain. According to the Centers for Disease Control and Prevention, 43% of laboratory-confirmed bacterial enteric infections in the United States are caused by Salmonella species, followed by Campylobacter species (33%), Shigella species (17%), Shiga toxin-producing Escherichia coli (4.1%), and Yersinia species (0.9%) (4).Although most common agents of bacterial enteric infection are easily cultivated on standard selective and differential bacteriologic media, isolation and final identification are time-consuming, leaving patients without a diagnosis for several days, and putting them at risk for untreated infection and spread of infection to others. Alternatively, empirical antimicrobial therapy may have adverse consequences for some diarrheal pathogens, such as E. coli O157:H7 (16). At Mayo Clinic (Rochester, MN), the time to final identification for Salmonella, Shigella, and Yersinia species from stool culture ranges from 3 to 5 days and that for Campylobacter species ranges from 2 to 4 days.We recently described a rapid real-time PCR assay for detecting Shiga toxin-producing E. coli in stool that showed performance equivalent to that of culture for detecting E. coli O157:H7 and which additionally detects non-O157 Shiga toxin-producing E. coli (6). We have also developed a stool PCR assay that is as accurate as culture for detecting toxigenic Clostridium difficile in stool samples (12). These assays are currently the only ones used for detection of the associated pathogens in our laboratory. Based upon the success of Shiga toxin and C. difficile stool PCR, we developed and validated assays to rapidly detect and differentiate Campylobacter, Salmonella, and Yersinia species, and Shigella species/enteroinvasive E. coli in stool and compared the results to those of routine stool cultures on specimens submitted for testing for enteric pathogens.(This study was presented in part at the 110th General Meeting of the American Society for Microbiology, San Diego, CA, 23 to 27 May 2010.)     

Procalcitonin as a predictor of severe appendicitis in children

The aim of this study was to assess the diagnostic value of procalcitonin (PCT) in 212 children with appendicitis and compare it with that of the standard diagnostic modalities, C-reactive protein (CRP) level, leukocyte count, and abdominal ultrasound findings, in relation to the surgical and histological findings of the appendix. A PCT value of >0.5 ng/ml was found to be indicative of perforation or gangrene with 73.4% sensitivity and 94.6% specificity, a CRP level of >50 mg/l and a leukocyte count of >10⁴/mm³ were useful diagnostic markers for perforation, while abdominal ultrasonography had a sensitivity of 82.8% and a specificity of 91.2% for detecting appendicitis with imaging findings. PCT measurement seems to be a useful adjunctive tool for diagnosing acute necrotizing appendicitis or perforation, and surgical exploration will probably be required in patients with PCT values >0.5 ng/ml.     

Assessment of the value of pelvic ultrasonography in pre-menopausal women with right iliac fossa pain

The aim of this study was to determine whether ultrasound examination performed in the acute setting can avoid the need for diagnostic laparoscopy in pre-menopausal women presenting with right iliac fossa pain in whom the diagnosis of acute appendicitis is suspected. All female patients aged fifty or under, who presented to the Emergency Department with right iliac fossa pain over an eighteen-month period, and who went on to have a diagnostic laparoscopy performed, were included in the study. Ultrasound and operative findings were recorded. 147 patients fulfilling the study criteria were identified. 38 (26%) had pre-operative ultrasound performed. 15 of these had normal findings, 10 had gynaecological pathology identified, 8 had non-specific findings. Of the 38 patients who had pelvic ultrasound pre-operatively, 26 (68%) had acute appendicitis at laparoscopy, only 5 of whom had a sonographic diagnosis of acute appendicitis made pre-operatively. We conclude that while positive ultrasound findings in cases of acute appendicitis are helpful, negative studies do not exclude the diagnosis. Patients in whom there is a strong clinical suspicion of acute appendicitis should proceed directly to laparoscopy while patients in whom the diagnosis is less certain, should be admitted for a period of observation facilitating repeated clinical evaluation. In this subgroup of patients, further imaging studies such as computed tomography may be indicated.     

Pseudoappendicitis caused by Plesiomonas shigelloides.

A 20-year-old patient was hospitalized with clinical signs of acute appendicitis. After surgery, the histological findings in the appendix and a lymphatic node suggested the diagnosis of pseudoappendicitis caused by Plesiomonas shigelloides, which was isolated in pure culture from the lymphatic node. The strain of P. shigelloides was found to elaborate a heat-stable toxin and harbored two plasmids of 280 and 4 kilobases. A large plasmid has previously been implicated as a virulence marker in P. shigelloides infections.     

Acute appendicitis due to both Klebsiella pneumoniae and serotype 35B Streptococcus pneumoniae, an emergent serotype

Streptococcus pneumoniae has been rarely considered as an infectious agent in appendicitis. We report a case of a 47-year-old woman with acute appendicitis caused both by serotype 35B S. pneumoniae and Klebsiella pneumoniae. The pathway of the appendix colonisation remains unclear. It could be explain by direct infection via mucosal translocation or by hematogenous spread. Pneumococcal appendicitis could progress to perforation more frequently. The use of intraoperative samples for management of appendicitis is controversial. But, culture with appropriate media is the only mean to isolate bacteria not very often encountered in appendicitis and to identify species of epidemiologic interest as serotype 35B S. pneumoniae, a non vaccinal serotype resistant to penicillin which is considered as a potential emergent pathogen. In the case of S. pneumoniae appendicitis, it could be recommended to take complementary directed samples to understand its pathophysiology.     

Sessile serrated adenoma is associated with acute appendicitis in patients 30 years or older

Sessile serrated adenoma is a relatively recently described entity that can occur in the appendix. The incidence of this finding is unknown. We entirely submitted 100 consecutive appendices sent for acute appendicitis and correlated the histologic findings with clinical parameters and the findings in 100 routinely (partially) submitted cases. In cases submitted routinely, only 1 sessile serrated adenoma was found. In contrast, in cases entirely submitted, 11 adenomas were found, all in patients 30 years or older. All sessile serrated adenomas were present in 3 cross-sections or fewer of the appendix. The incidence of sessile serrated adenoma in patients with acute appendicitis is significantly increased in patients 30 years or older (P = .001), and detection is dependent on thorough tissue sampling.