Quantitative study of the aerobic and anaerobic faecal flora in neonatal necrotising enterocolitis.

Abstract

SUMMARY Faeces from 24 neonates with proved necrotising enterocolitis (NEC), from 12 with clinically suspected NEC, and from 41 control infants were quantitatively cultured under aerobic and anaerobic conditions. An important difference in colonisation with Klebsiella was found between the NEC groups and the control group. Although the cause of NEC is unknown, colonisation with Klebsiella seems to increase the risk.Necrotising enterocolitis (NEC) is found especially among preterm infants. Its principal clinical signs are distended abdomen, retention of food, and faecal blood loss. A typical radiological appearance is gas in the intestinal wall (pneumatosis intestinalis) and evidence suggests that this gas originates from bacteria.1 NEC is usually found in the terminal ileum, but it may extend to other parts of the intestine. It is associated with necrosis of the intestinal wall and in many cases leads to perforation and peritonitis. The incidence is usually reported as 10-1-5/1000 live born infants, with a mortality of about 30 %. Published figures show that the incidence of NEC is higher and the prognosis more unfavourable in infants of low birthweight and young gestational age.2 Although NEC is an important problem in neonatal intensive care units (ICU), its cause is unknown. Several factors probably play a part in its aetiology-intestinal mucosal injury (caused by ischaemia, mechanical damage, or toxic substances), enteral feeding, and the presence of bacteria.3 Whether certain bacterial species increase the risk of NEC is uncertain and a prospective controlled study of the faecal flora in NEC was undertaken to investigate this. MethodsPatients. Three groups of patients were studied. Group 1 comprised 24 children in whom NEC was diagnosed radiologically or at operation, or both, or at necropsy. Group 2 comprised 12 children who showed clinical signs of NEC-distended abdomen, retention of food, and facael blood loss-but in whom the diagnosis could nct be proved. Group 3 comprised 41 control infants, matched for birthweight and gestational age, who were cared for in the same ICU during the study period. A subgroup of the controls was considered separately in the analysis of results. This was group 4, comprising 19 children whose faeces were cultured within 7 days before or after NEC was diagnosed in another child in the ICU.Collection of material and culture. Between 20 September 1980 and 1 January 1982, faeces were collected from children who were at high risk from NEC. These were infants aged less than 1 month, born at a gestational age of less than 34 weeks, and with a birthweight of less than 2000 g, who were admitted to the ICU. Faecal cultures were made on the first day of illness in groups 1 and 2. In group 3 this was done on about day 10, which is the usual age of onset of NEC.After collection, a small amount of faeces was transferred to a bottle containing 3 ml glycerol broth, stored at 4°C, and used within 24 hours for quantitative cultures under aerobic and anaerobic conditions.4 The amount of faeces...

Evidence for Clostridial Implication in Necrotizing Enterocolitis through Bacterial Fermentation in a Gnotobiotic Quail Model

“…Moreover, several authors did not find any relation between the isolation of C. difficile and/or detection of its toxins and NEC (21,24,25). In Westra-Meijer's study (19), C. difficile colonization was similar in the NEC groups and the healthy group (~50%). However, in very rare cases, C. difficile might be involved in severe enterocolitis in infants, the most obvious relationship being in regards to enterocolitis in Hirschsprung's disease (26).…”

“…Westra-Meijer et al (19), comparing aerobic and anaerobic fecal flora in healthy preterm infants and infants with NEC, observed a higher colonization with Klebsiella species in infants with NEC but no difference in clostridia populations. Nevertheless, a careful analysis of the published results showed that the proportion of infants who were colonized with high levels of clostridia (Ն10 8 /g of feces) was higher in the two NEC groups (54%) than in the healthy group (25%).…”

“…Moreover, compared with C. butyricum, butyric acid is also a major end product of lactose fermentation by C. perfringens, and when quails were fed a diet deprived of lactose, no lesion was observed (16). C. paraputrificum, like C. butyricum, may be found in healthy neonates (19,29,30) and does not produce any toxin. It is a lactose-fermenter species that produces acetic and butyric acids.…”

Early Intestinal Bacterial Colonization and Necrotizing Enterocolitis in Premature Infants: The Putative Role of Clostridium

“…Previous studies have explored the establishment of bacterial flora in term and preterm infants (2)(3)(4). Several studies noted that initial bacterial colonization could play a pivotal role in the development of NEC (5-7).…”

Neonatal Necrotising Enterocolitis

“…from peritoneal fluid or blood and more severe disease. Clostridium bulyricum and Clostridium difficile have also been implicated in the pathogenesis of NEC [47,48] but these organisms are frequently iso lated from the stools of asymptomatic neo nates [49][50][51][52][53].…”