Is there a role for Serratia marcescens in male infertility: An experimental study?

OBJECTIVE: Establishment of a male BALB/c mouse model to study the role of sperm impairing S. marcescens on mouse reproductive potential. The current study can add to use of reliable animal models to provide a noteworthy evidence for the microbial cause of infertility.

METHODS: The mice in the test groups II, III, IV were intraperitoneally administered with different doses (10(4), 10(6) or 10(8) cfu) of S. marcescens whereas, group I serving as control, received PBS, for 10 consecutive days. The groups were evaluated for any change in body weight, tissue somatic index (%), seminal parameters and histology. Confirmation of S. marcescens from reproductive organs was done by reisolating the same by cultural characteristics and biochemical tests.

RESULTS: The results showed that weight gain was evident only in mice receiving PBS (group I), whereas a decrease was recorded in the test groups (group II, III and IV). Only testes of test groups showed significant changes in TSI values whereas, no change in TSI was observed in any reproductive organ of any test group. Seminal parameters viz. sperm count, motility and viability were found to decrease in test groups II, III and IV as compared to control group I. Interestingly, the number of pus cells and percent decapitation was more prominent in test groups which received higher doses (i.e. group III and group IV). The histopathological examination revealed mild to dense inflammation in vas deferens and caudal epididymis in all test groups except hypospermatogenesis which was observed only in test group III and IV. However, in group I, neither adverse changes nor any sign of inflammation were observed.

CONCLUSION: Intraperitoneal inoculation of S. marcescens could lead to alteration of semen parameters, induction of decapitation in spermatozoa and histopathological changes, thereby decreasing the reproductive potential of male mice.