Amniotic fluid antibacterial activity and nutritional parameters in term Mozambican and Swedish pregnant women

Purification and antimicrobial activity studies of the N-terminal fragment of ubiquitin from human amniotic fluid

A 4.3-kDa antimicrobial peptide was isolated from human amniotic fluid by dialysis, ultrafiltration, and C18 reversed-phase high performance liquid chromatography. This peptide, which we named Amniotic Fluid Peptide-1 (AFP-1), possessed antimicrobial activity but lacked hemolytic activity. In addition, AFP-1 potently inhibited the growth of a variety of bacteria (Escherichia coli, Salmonella typhimurium, Listeria monocytogenes and Staphylococcus aureus), filamentous fungi (Botrytis cinerea, Aspergillus fumigatus, Neurospora crassa and Fusarium oxysporum) and yeast cells (Candida albicans and Cryptococcus neoformans). Automated Edman degradation showed that the N-terminal sequence of AFP-1 was NH(2)-Met-Gln-Ile-Phe-Val-Lys-Thr-Leu-Thr-Gly-Lys-Thr-Ile-Thr-Leu-Glu-Val-Glu-. The partial sequence had 100% homology to the N-terminal sequence of ubiquitin. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry revealed that the molecular mass of AFP-1 was 4280.2 Da. Our data show an antimicrobial activity of ubiquitin N-terminal derived peptide that makes it suitable for use as an antimicrobial agent.

Antimicrobial polypeptides of human vernix caseosa and amniotic fluid: implications for newborn innate defense

Antimicrobial peptides/proteins are widespread in nature and play a critical role in host defense. To investigate whether these components contribute to surface protection of newborns at birth, we have characterized antimicrobial polypeptides in vernix caseosa (vernix) and amniotic fluid (AF). Concentrated peptide/protein extracts were obtained from 11 samples of vernix and six samples of AF and analyzed for antimicrobial activity using an inhibition zone assay. Proteins/peptides in all vernix extracts exhibited strong antibacterial activity against Bacillus megaterium (strain Bm11), in addition to antifungal activity against Candida albicans, whereas AF-derived proteins/peptides showed only the former activity. Fractions obtained after separation by reverse-phase HPLC exhibited antibacterial activity, with the most pronounced activity in a fraction containing alpha-defensins (HNP1-3). The presence of HNP1-3 was proved by dot blot analysis and confirmed by mass spectrometry. Lysozyme and ubiquitin were identified by sequence analysis in two fractions with antibacterial activity. Fractions of vernix and AF were also positive for LL-37 with dot blot and Western blot analyses, and one fraction apparently contained an extended form of LL-37. Interestingly, psoriasin, a calcium-binding protein that is up-regulated in psoriatic skin and was found recently to exhibit antimicrobial activity, was characterized in the vernix extract. The presence of all of these antimicrobial polypeptides in vernix suggests that they are important for surface defense and may have an active biologic role against microbial invasion at birth.

Introduction of the Misgav Ladach caesarean section at an African tertiary centre: a randomised controlled trial

OBJECTIVE

To determine whether the Misgav Ladach caesarean section technique can offer benefits compared with conventional caesarean section technique in the prevailing conditions of a busy African tertiary centre.

DESIGN

A randomised controlled trial.

SETTING

A tertiary African obstetric unit with 18,000 deliveries annually.

PARTICIPANTS

Three hundred and thirty-nine women undergoing caesarean section.

METHODS

Eight residents and registrars were instructed in the Misgav Ladach technique for caesarean section during one week, after which the study commenced. The course participants instructed their colleagues; in total, 16 doctors participated. Women requiring caesarean section were randomised to Misgav Ladach or to the conventional lower midline incision procedure, excluding those with a previous scar.

RESULTS

During 11 weeks 339 randomised procedures (328 of which were emergency procedures) were carried out. Mean operating time was 25 x 3 minutes for Misgav Ladach and 32 x 6 minutes for the lower midline incision procedure (95% CI -8 x 3; -6 x 3). Mean blood loss was 354 mL and 447 mL (-133; -53), and the number of sutures 3 x 1 and 6 x 1 (-3 x 1; -2 x 9), respectively. No significant difference was found in Apgar scores. Mobilisation was earlier with the Misgav Ladach procedure. No difference was found in overall post-operative infection rates i.e. wound infection or febrile illness, but the combination of wound infection and fever was more common in the Misgav Ladach group.

CONCLUSION

The Misgav Ladach caesarean section confers benefits such as reduced blood loss, conservation of time and suture material, and rapid mobilisation, but more studies are needed to explore modifications aimed at reducing post-operative infections in settings with limited resources.