Journal of Postgraduate Medicine
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Year : 1981  |  Volume : 27  |  Issue : 2  |  Page : 99-104  

Non-specific seminal tract infection and male infertility : a bacteriological study.

NN Mogra, AA Dhruva, LK Kothari 

Correspondence Address:
N N Mogra


70 infertile males with epididymal tenderness, pus cells in the semen, and/or history of urinary tract infection were studied by semen culture examination. Significant growth of Streptococcus fecalis, Escherichia coli, coagulase positive Staphylococci, Proteus valgaris, Pseudomonas pyocyanea, and beta hemolytic Strepticocci was found in 42.9% of the cases. Most of the tested strains were sensitive to ampicillin, cotrimoxazole, nitrofurantoin, erythromycin, and chloramphenicol. In a control group of 20 healthy fertile males, only an insignificnat growth of Staphylococcus albus and Streptococcus facalis was found in 65% of the samples. Nonspecific seminal tract infection can be an important cause of male infertility. These infections may affect fertility in several ways: by damaging sperm, hampering their motility, altering the chemical composition of the seminal fluid, or by producing an inflammatory structure in the tract. Seminal infection could also be the cause of the chronicity of urinary tract infection by acting as the reservoir of infection.

How to cite this article:
Mogra N N, Dhruva A A, Kothari L K. Non-specific seminal tract infection and male infertility : a bacteriological study. J Postgrad Med 1981;27:99-104

How to cite this URL:
Mogra N N, Dhruva A A, Kothari L K. Non-specific seminal tract infection and male infertility : a bacteriological study. J Postgrad Med [serial online] 1981 [cited 2023 Feb 1 ];27:99-104
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Nonspecific seminal tract infection, other than sexually transmitted diseases and tuberculosis, can play an important role in the etiology of male infertility.[5] Such infections may often go unnoticed but could hamper fertility in several ways. Inflammation and fibrosis could obstruct the passage, sperms could be directly damaged and immobilised7, 11 or the chemical composition of the seminal plasma could be adversely affected. Keeping this in view, we have investigated the role of non-specific bacterial infections in relation to male infertility and delineated appropriate therapeutic measures through semen culture and antibiotic sensitivity tests.


This study is based on 90 male subjects (age 20 to 42 years) divided into two groups:

Group 1 (infertile) : This group consisted of 70 patients attending the Male Fertility Clinic (Human Fertility Research Unit) under the Department of Physiology, Rabindranath Tagore Medical College, Udaipur, during 1976-78, for investigation of an infertile marriage. They were selected for bacteriological study on the basis of one or more of the following conditions:

(a) Epididymal tenderness,

(b) Presence of pus cells in the seminal fluid,

(c) Positive history of urinary tract infection.

Group 2 (Control) : This group consisted of 20 married males of proven fertility without any urinary complaints, epididymal tenderness or pus cells in the semen.

None of the subjects, in either group, were on antibiotic therapy during or just prior to the study.

The seminal fluid was collected by masturbation in a sterile petri-dish, under aseptic precautions, after 5 days' abstinence. Mid-stream urine was collected for culture 2-5 days after the semen collection but never on the same day. This was possible in all the 20 fertile subjects (control) and 23 infertile patients taken randomly.

Bacterial culture

The semen was allowed to liquefy completely and then inoculations were done with undiluted, 1:10 diluted, and 1:100 diluted samples using standard loop method. The diluent used was sterile distilled water and the bacterial count was done by the method described by Hoeprich4 Undiluted samples were inoculated on nutrient agar, blood agar, McConkey's agar, chocholate agar and glucose and thioglycollate broths. Diluted samples were inoculated separately on nutrient agar and blood agar media. All the medic, were incubated at 37C for 18 to 24 hours and then examined for any evidence of growth. Subcultures on solid media and biochemical tests were employed for the proper identification and confirmation of the organisms isolated 2 Urine samples were cultured in a similar manner on nutrient agar, McConkey's agar and glucose broth.

(B) "In-vitro" antibiotic sensitivity tests were done against the organisms isolated by the standard disc diffusion technique.'

(C) V.D.R.L. test was done in cases giving a history of contact by slide flocculation technique.3

(D) Routine semen examination was done for sperm count, motility, morphology and presence of pus cells and R.B.C.

(E) Statistical analysis was done by Student's `t' test for unpaired data.


In the 70 infertile males investigated, epididymal tenderness was present in 90% cases, including 30% who also had significant number of pus cells in the semen (more than 10 per high power field) and 14.3% who gave a positive history of urinary tract infection. Remaining 10% did not have epididymal tenderness or a definite history of urinary tract infection but had a substantial number of pus cells in the semen. In 27.1% of the patients, there was azoospermia while in 61.4% there was oligospermia with sperm counts below 40 million/ml. The remaining 11.5% cases had counts in the normal range. In the control (fertile) group, the sperm counts ranged between 55 to 110 million/ml.

The frequency and the type of organisms isolated from the semen are shown in Table 1. Similarly, the bacteria isolated from urine in both the groups are shown in Table 2. The correlation between the culture findings in the semen and the urine is shown in Table 3. "In vitro" antibiotic sensitivity of the isolated strains, employing the antibiotics at present in clinical use, is shown in Table 4.

A good number of cases (35.7%) gave a positive history of contact. Only 3 out of 25 such cases, however, had a positive V.D.R.L. test. All these 3 had taken long acting penicillin injections and their semen revealed no growth on bacterial culture.


The idea that bacterial infections may be partly responsible for male infertility arises from the clinical observation that epididymal tenderness is surprisingly common in such patients. In out patients, the tenderness was sometimes quite severe and radiating into the abdomen, but still they had never considered it necessary to seek medical advice for this. Almost 30% of these patients also had pus cells in the seminal fluid, again indicating infection. Homonnai5 successfully treated a few patients of male infertility with a standard regime of an antibiotic (Ampicillin) and an anti-inflammatory agent (Phenylbutazone). Nikkanen et al6 also observed silent infection of the male accessory genital organs in 22.3% of infertile men. But a course of tetracycline or sulfonamide-trimethoprim combination upto 4 weeks proved inadequate in controlling the infection and restoring fertility.

In the present study, only 10% of the infertile patients gave no growth on semen culture while in the remaining 90%, one or more types of bacteria were isolated. If those with less than 10,000 bacteria per ml are regarded as pathologically insignificant, the incidence falls to 42.9%. The excluded group consisted almost exclusively of Staphylococcus albus which is a common contaminant from skin and urethral meatus. Amongst the 42.9% samples giving a significant bacterial growth, the type of organisms isolated were Streptococcus fecalis (31.4%), Escherichia coli (17.1%), coagulase positive Staphylococci (14.3%) and in a few cases Proteus, Klebsiella, Pseudo, monas and beta-hemolytic Streptococci (Table 1). Other workers have found Corynebacterium,10 Escherichia coli12 and Gaffkiya9 as the common pathogens in the semen of infertile males. By contrast, 35% samples of the control group were sterile on culture and in the remaining 65% only quantitatively insignificant numbers of Staphylococcus albus and Streptococcus fecalis were grown. The comparable frequency of the Staphylococcus albus and Streptococcus fecalis in the 2 groups (Table 1) further substantiates their commensural status.

A maximum number of strains of Staphylococcus albus, Streptococcus fecalis and Escherichia colt were sensitive to Ampicillin, followed by Trimethoprim-Sulphamethoxazole (Co-trimoxazole), Nitrofurantoin, Erythromycin and Chloramphenicol (Table 4). The development of bacterial resistance against Penicillin, Sulphadimidine and Tetracyclines perhaps reflects upon the practice of too frequent and indiscriminate use of these antibiotics. All the strains of Staphylococcus aureus revealed resistance against Penicillin, thus indicating the high prevalence of Penicillin resistant Staphyfococci in this region.

An effort has also been made to correlate sperm count with the type or number of organisms isolated from semen. Out of 70 cases of infertility, 19 had azoospermia while 32 revealed oligospermia. No definite relationship could be observed between the type of bacteria and the sperm count. Although the immobilising effect of certain bacteria, particularly Escherichia colt,[11] on spermatozoa has been demonstrated, this cannot be the mechanism responsible for the oligospermia. An inflammatory obstruction in the seminal passage could be a more likely explanation as suggested by the presence of epididymal tenderness, pus cells in the semen and the isolation of pathogenic bacteria.

We could not obtain any direct correlation between the number of pus cells and the type of bacteria in the semen as noted by some other workers.[10],[12] But pathogenic organisms like Pseudomonas, Proteus, beta-haemolytic Streptococci and some strains of Staphylococcus aureus were isolated from the samples which had large number of pus cells (more than 10 per high power field). This can be expected on the basis of the chemotactic property of bacteria and/or their products. The accumulation of the neutrophilic leucocytes, which form the pus cells, is influenced by the positive chemotactic force at the local site and this property varies with the type of the organisms.

Urine culture gave essentially similar growth in 60.9% of the infertile males tested while in 30.4% subjects the urine was sterile (Table 3). It is assumed that urinary tract acts as a nidus of infection for the seminal tract. It is possible that the infected seminal tract, relatively inaccessible to most antibiotics, may then act as a reservoir of infection and may charge the urinary bladder from time to time by retrograde ejaculation. This could, therefore, be a factor in maintaining the chronicity of urinary infections in males.

Rehewy et al8 obtained positive bacterial cultures from the semen of 73% of asymptomatic infertile men. The most common aerobic organisms grown were Corynebacterium, Staphylococcus aureus. Staphylococcus epidermidis, Escherichia colt, Proteus mirabilis, Klebsiella pneumouiae and Mycoplasma, while amongst the anaerobes, Peptostreptococcus and Bacteroides fragilis were mostly isolated. Interestingly enough, 54% of the fertile controls also had a positive bacterial culture, largely confined to Staph. epidermidis, Staph. aureus and Corynebacterium. Obviously, a mere presence of bacteria in the ejaculate does not exclude fertility and their nature as well as numbers have to be taken into account while evaluating an infertile male. Thus, it would be worthwhile to screen all infertile males for a possible silent seminal tract infection and vigorously institute appropriate anti-bacterial therapy wherever indicated by significant semen culture.


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